Head and Neck Flashcards
(554 cards)
1
Q
Where does the neck descend from and to?
A
The lower margin of the mandible to the suprasternal notch of the manubrium, and upper part of the clavicle.
2
Q
Where is the investing fascia attached to - superiorly, posteriorly and inferiorly?
A
Superiorly - lower mandible, mastoid process, superior nucheal line and external occipital protuberance.
Posteriorly - spinous processes and ligamentum nuchae.
Inferiorly - clavicle, acromium and spine of the scapula.
3
Q
What muscles and glands does the investing layer split?
A
Muscles - sternocleidomastoid and trapezius.
Glands - parotid and submandibular.
4
Q
What is the pre-tracheal layer attached to superiorly, and what does it blend to inferiorly?
A
Attached to the hyoid bone, blending with the fibrous pericardium, in the thorax.
5
Q
What are the two layers of the pre-tracheal fascia?
A
Muscular layer - enclosing the infrayoid muscles.
Visceral layer - enclosing the thyroid gland, trachea and oesophagus.
6
Q
Where does the pre-vertebral fascia extend to and from?
A
From the base of the cranium to the 3rd thoracic vertebra.
7
Q
Where does infection within the deep neck spaces often arise from, and why are they not actually spaces?
A
They arise from the teeth, tissues of the pharynx or sinuses.
They are filled with loose connective tissue.
8
Q
What can physical compression of a retopharyngeal abscess cause?
A
Airway issues, due to the close proximity of the trachea.
9
Q
Why are retropharyngeal abscesses more common in children?
A
Retropharyngeal lymph nodes atrophy after the age of 3-4.
10
Q
What is the more common cause of retropharyngeal abscesses in adults?
A
Penetrating injuries of the pharynx or oesophagus.
11
Q
How can a goitre cause impedance of venous blood vessels, and what can this present as?
A
It can extend retrosternally, compressing them.
This means there is an accumulation of blood, causing facial plethora.
12
Q
What is the Pemberton manoeuvre?
A
When the arms are raised above the head, there is narrowing of the thoracic inlet, meaning that facial plethora will develop, due to compression of the venous structures by a retrosternal goitre.
13
Q
What is the main function of the scalene muscles, and what do they form?
A
Accessory muscles of respiration.
They form the floor of the posterior triangle.
14
Q
What muscles do the trunks and subclavian vessels pass between?
A
The anterior and middle scalenes.
15
Q
What is the function of the buccinator?
A
Keeping the cheeks taut to prevent food from pooling between the cheeks and teeth.
16
Q
What are the different muscles that are involved in elevating and depressing the mandible?
A
Elevating - medial pterygoid, temporalis and masseter.
Depressing - lateral pterygoid and suprahyoids (4).
17
Q
What do the pterygoid muscles attach to?
A
They originate from the pterygoid plates, located at the base of the skull.
They insert onto the mandible.
18
Q
What are the two bellies of the occipitofrontalis, what are they joined by and what are each of their actions?
A
Occipitalis and frontalis, joined by the epicranial aponeurosis.
Frontalis - attaches to the skin of the eyebrows to wrinkle the skin.
Occipitalis - movement of the scalp.
19
Q
Where is the orbicular oculi located and what are the two bellies’ role?
A
Encircling the orbits of the eyes.
Orbital is to protect the eyes by squeezing them tightly.
Palpebral is to close them gently to keep the eyes moist - blinking.
20
Q
What is the origin and insertion of the orbicularis oris and what is its function?
A
It arises from the maxilla and mandible, and inserts into the skin and membrane of the lips.
It’s function is to purse the lips together for speech and to seal the mouth closed whilst eating.
21
Q
What is the origin and insertion of the platysmus, and what is the function?
A
Arises from the fascia of the anterior chest, inserting into the mandible and overlying subcutaneous tissue.
It function is to tense the skin, and to a small degree, depress the mandible.
22
Q
What are the cranial nerves of the facial and trigeminal nerves?
A
Facial - 7.
Trigeminal - 5.
23
Q
What are the 5 extra-cranial branches of the facial nerve?
A
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Temporal.
Zygomatic.
Buccal.
Marginal Mandibular.
Cervical.
24
Q
What is the House-Brackmann’s scale?
A
A scale used to determine the severity of the facial nerve injuries.
25
Which branch of the trigeminal nerve innervates the muscles of mastication?
The mandibular division of the trigeminal nerve.
26
What is the nerve supply to the supra-hyoid and infra-hyoid muscles?
Supra-hyoids - cranial nerves 5 and 7.
Infra-hyoids - cervical nerves (C1-C3), ansa cervicalis.
27
What is torticollis?
Involuntary contraction of the sternocleidomastoid, causing asymmetrical head/ neck position.
Can be acquired or congenital.
28
What is the sternocleidomastoid and trapezius innervated by?
Accessory nerve - cranial nerve 11.
29
What are the borders of the anterior triangle?
Medial - midsagittal line of the neck.
Lateral - anterior border of the sternocleidomastoid.
Superior - inferior border of the mandible.
30
What are the borders of the posterior triangle?
Posterior - anterior trapezius.
Anterior - sternocleidomastoid.
Inferior - clavicle.
Floor - scalene muscles.
Roof - cervical fascia.
31
What 3 things are enclosed in the carotid sheets?
Internal jugular vein (laterally), the common carotid artery (medially) and vagus nerve (posteriorly).
32
What are the contents of the posterior triangle?
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S - Scalene muscles.
P - Phrenic Nerve.
B - Brachial plexus (trunks).
S - subclavian vessels.
P-O - posterior omohyoid.
A - accessory nerve.
E - external jugular vein.
33
What runs within the superficial cervical fascia?
The accessory nerve and the external jugular vein.
34
What is the main complication of a retropharyngeal abscess?
Mediastinitis.
35
What is the commonest presentation of a facial nerve lesion, and what is the most common aetiology?
Bell’s Palsy.
Viral infection, predominantly herpes virus.
36
What is the function of the medial and lateral pterygoids, when working together?
To move the mandible side to side.
37
Which muscles retract and protract the mandible?
Retract - temporalis.
Protract - medial and lateral pterygoids, and partially the masseter.
38
Outline the action, location and innervation of the digastric muscle.
39
Outline the action, location and innervation of the omohyoid muscle.
40
What layer of the scalp are the 5 arteries supplying the scalp found in?
The dense connective tissue layer.
41
What nerve is the carotid sinus a branch of, and what types of specialised cell does it contain?
The glossopharyngeal nerve.
It contains baroreceptors.
42
Where is the superior cervical ganglion located?
Posterior to the carotid sheath, at the level of the 2nd and 3rd vertebra.
43
Which vertebra does the vertebral artery not run through? State what the transverse foramina does transmit.
C7 - instead it runs anterior to the transverse foramen. It only transmits the vertebral vein.
44
What nerve does the inferior thyroid nerve travel anterior to, and what is its function?
Recurrent laryngeal nerve.
It is a branch of the vagus nerve that gives sensory and motor innervation to the larynx.
45
What is the intra-cranial drainage into the internal jugular vein?
The sigmoid sinus drains directly into the internal jugular vein.
The cavernous sinus drains into the internal jugular vein via the superior and inferior petrosal sinuses.
46
Outline the route of the internal jugular vein (IJV) back to the heart.
IJV drains into the subclavian vein, then into the brachiocephalic trunk, then into the SVC and then into the right atrium.
47
What is the pterygoid venous plexus located within?
The infra-temporal fossa.
48
Outline the superficial veins that drain intra-cranially.
49
What 2 veins drain into the external jugular vein?
The superficial temporal vein an the posterior auricular vein.
50
What do emissary veins do?
Drain extra-cranial veins into the dural venous sinuses.
51
Where is the carotid body located, and what types of cells does it contain?
Located within the adventitia of the common carotid bifurcation.
It contains chemoreceptors that monitor blood-oxygen concentration. It is also sensitive to pH and blood-carbon dioxide concentration.
52
What nerve supplies the carotid sinus and carotid body?
Carotid sinus nerve - a branch of the glossopharyngeal nerve - sends signals to the brainstem.
53
What pathological condition can arise in the superficial temporal artery? Describe it and its main complication.
Temporal arteritis - inflammation of the walls of the artery, leading to them hardening. It can lead to vision loss in the eye due to it giving branches to the retina of the eye.
54
State the 2 main branches of the maxillary artery and their functions.
Middle meningeal artery which runs behind the pterion, anterior to the periosteum to supply the meninges and skull.
Sphenopalatine artery which supplies the nasal cavity. This is a source for epistaxis (nose bleeds).
55
What do the following branches of the ECA supply:
- Superior thyroid.
- Lingual.
- Facial.
- Occipital.
- Posterior auricular.
- Maxillary.
- Superficial temporal.
ST - thyroid gland.
L - tongue.
F - main tissues of the face (from behind the mandible to the corner of the eye).
O - posterior scalp.
PA - posterior to the ear to supply the posterior scalp.
M - deep facial structures.
ST - anterior to the ear.
56
What kind of haemorrhage and shape does a middle meningeal artery laceration cause?
Extradural haemorrhage.
57
What are the 2 branches of the internal carotid, as it exits the cavernous sinus?
Opthalamic artery, which enters the orbit.
Branches that enter the circle of Willis.
58
What procedure is performed to remove the atherosclerotic plaque at the bifurcation of the common carotid artery?
Carotid endartectomy.
59
Where does the IJV begin from, and what is it a continuation from?
Formed at the jugular foramen, as a continuation of the sigmoid sinus.
60
Why do you use the internal jugular vein, as opposed to the subclavian vein, for insertion a central line?
Less risk of pneumothorax.
61
What gland do the maxillary and superficial temporal arteries supply blood to?
Parotid gland.
62
What does the perpendicular plate help to form?
Septum of the nose.
63
What is the Crista galli an attachment for?
Falx cerebri.
64
What does the petrous bone house, and how is it adapted for this?
Cochlea and vestibocochlear nerve.
These are delicate so it is extremely hard.
65
What can ethmoid fractures present with?
CSF rhinorrhoea.
66
What X-ray view would a zygomatic arch fracture and mandibular fracture be taken in, respectively?
Zygomatic arch - bucket-handle.
Mandibular - OPG = orthopartomogram, which pans round.
67
What is the boundary between the middle and posterior cranial floors?
The petrous part of the temporal bone.
68
In what bone is the stylomastoid foramen located, and what does it transmit?
The temporal bone.
It transmits the facial nerve.
69
What two bones is the jugular foramen formed between?
The occipital and temporal (petrous part) bones.
70
Outline some regions in which the lymph nodes can be palpable and non-palpable.
When are palpable lymph nodes often seen without infections?
Cervical lymph nodes can be palpable in children (28-55%).
71
What are the locations of the tonsils in the Waldeyer’s ring?
Pharyngeal/ adenoid - nasopharynx.
Tubal - nasopharynx.
Palatine - oral cavity.
Lingual - back of the posterior aspect of the tongue.
72
What can andenoid tonsil swelling lead to?
Obstruction of nasal breathing.
Snoring.
Blockage of the Eustachian tube, potentially leading to infection in the middle ear.
73
What is the most common cause of tonsillitis and which tonsils are most commonly seen?
Viral aetiology.
The palatine tonsils, with inflammatory exudate present - this is extensive in streptococcus pyogenes infections.
74
What do the superficial cervical lymph nodes drain and where are they found, collectively?
They are found in the superficial cervical fascia.
They drain the face, scalp and parts of the tongue.
75
What do the post-auricular (superficial) lymph nodes drain?
Posterolateral half of the scalp.
76
What do the submental (superficial) lymph nodes drain?
Inferior and posterior chin.
Floor of the mouth.
Tip of the tongue.
Lower incisor teeth and gums.
77
What do the occipital (superficial) lymph nodes drain?
Posterior scalp.
78
What do the pre-auricular and parotid (superficial) lymph nodes drain?
Anterolateral scalp.
Upper half of the face including the eye lids.
Cheeks.
79
What do the submandibular (superficial) lymph nodes drain?
The centre of the face and cheek.
Teeth and gingivae - gums.
Parts of the anterior tongue.
80
What lymph nodes can conjunctivitis cause swelling of?
Pre-auricular and parotid superficial lymph nodes.
81
What drains the different aspects of the tongue?
82
What are the 3 different deep cervical lymph nodes, where do they all receive drainage from collectively?
Jugulo-digastric.
Jugulo-omohyoid.
Supraclavicular.
They all receive drainage from the superficial lymph nodes.
83
Where are the jugulo-digastric lymph nodes found and what do they drain, specifically?
Related to the upper third of the internal jugular vein, within the carotid sheath.
They drain the tonsils, tissues of the upper digestive tract, pharynx and part of the tongue.
84
Where are the jugulo-omohyoid lymph nodes found and what do they drain, specifically?
Associated with the lower third of the internal jugular vein, within the carotid sheath.
Drains part of the tongue, oral cavity, trachea, oesophagus and thyroid gland.
85
Where are the supraclavicular lymph nodes found and what do they drain, specifically?
They are found within the supra-clavicular fossa, in the posterior triangle.
They drain the deep parts of the thoracic and abdominal cavity.
86
What is cervical lymphadenitis, and how does it present?
Infection/ inflammation of the lymph nodes.
It presents with unilateral, red, hot lumps in the neck, often with fever. This is due to bacteria within the lymph node.
87
What is the palpation of lymph nodes with metastatic cancer like?
It is hard, tethered to the surrounding tissues and painless to the patient.
88
What is the palpation of lymph nodes with lymphoma like?
Rubbery, fast-growing and painless to palpate.
89
What forms the border between the anterior and middle cranial fossa?
The lesser wings of the sphenoid.
90
What forms the border between the middle and posterior cranial foramen?
The petrous bone of the temporal bone.
91
What two pathologies of the thyroid may cause a (off-)midline neck lump?
Malignant or benign neoplasm, forming a nodule or lump within the gland.
Diseases causing diffuse enlargement - goitre, such as Grave’s disease.
92
What are some pathologies that can cause salivary gland lumps, and which glands are they most common in - where would they be located?
Calculus (stone).
Inflammation or infection.
Neoplasm - benign or malignant.
They are most common in the submandibular or parotid glands.
They would be located in the lateral aspect of the neck.
93
What are some causes for vascular lumps within the neck, and where would they be located?
How can these be distinguished from other lumps?
Aneurysm of the carotid artery.
Carotid body tumours.
They are found in the lateral aspect of the neck.
They have a pulsating nature and are able to move side to side, not up and down.
94
What are two possible causes for benign lumps of the skin or subcutaneous tissue?
Lipoma - can be moved around and able to get under it.
Sebaceous cyst.
These can be found anywhere on the neck.
95
List the 5 possible congenital lesions causing neck lumps, and where would they be seen?
Thyroglossal duct cysts - midline.
Branchial cyst - lateral, in the anterior triangle.
Dermoid cyst - midline.
Laryngocoele - lateral (air filled sac).
Cystic hygroma - lateral, in the posterior triangle.
96
What are cystic hygromas, what is their aetiology and what is the management?
They are fluid-filled sacs that transilluminate and can be compressed.
They occur in infants/ fetal development due to lymphatic malformation.
They can be treated with surgical excision or drainage.
97
How do thyroglossal duct cysts present?
They are non-tender, well-defined lumps that are found deep to the cervical fascia.
They therefore moves up with tongue protrusion.
98
What can thyroglossal ducts complications be, and how are they treated?
They can become inflamed and infected, leading to them becoming painful.
This requires antibiotic treatment and surgical excision.
99
What arteries run into the subarachnoid space, and what do they form? What do these run alongside?
The vertebral arteries and internal carotid artery, forming the cerebral arteries.
The cerebral veins also run in this space which drain into the dural venous sinuses.
100
Describe the 3 layers of the meninges.
Pia mater - a microscopically thin layer that adheres completely to the brain, following the sulci (dips) and gyri (bumps).
Arachnoid mater - this is a soft, fibrous translucent membrane.
Dura mater - formed of a periosteal layer which is lines the inner table of the calvaria and the meningeal layer which is on the inner aspect. There is only a single layer that surrounds the spinal cord, not 2 like with the brain.
101
What is between the dura and the arachnoid mater, and why is this the case?
There is a potential space between them, and the CSF within the subarachnoid space pushes the arachnoid mater against the dura mater.
102
What is the tentorial notch, and what goes through it?
Space that is formed between the inner surfaces of the tentorium cerebelli.
The brainstem traverses through.
103
What do the superior and inferior petrosal sinuses run between?
Superior petrosal sinus is between the cavernous sinus and the transverse sinus.
Inferior petrosal sinus is between the cavernous sinus and the sigmoid sinus.
104
What dural venous sinus is formed between the junction of the falx cerebri and tentorium cerebelli? What does it drain into and what drains into it?
The straight sinus, which drains into the confluence of the sinuses.
The inferior sagittal sinus drains to this.
105
Where are the cavernous sinuses located?
In the middle cranial fossa, either side of the body of the sphenoid.
106
What do the bridging and emissary veins run between, respectively?
Bridging veins from the dural venous sinuses to the cerebral veins of the subarachnoid space.
Emissary veins from the scalp into the dural venous sinuses.
107
What is the clinical appearance of an extradural haemorrhage?
Rupture of a meningeal artery (often middle) due to significant head trauma (often at the pterion), leading to bleeding within the space between the periosteal dura mater and calvaria. Consciousness can be lost for seconds to minutes before waking up and behaving normal for around an hour - lucidity period. They then rapidly deteriorate in neurological function, due to compression of the intra-cranial contents.
108
What is the radiographical appearance of an extradural haemorrhage?
A lentiform appearance due to blood pooling between the inner table of the skull and the periosteal layer of the dura mater.
Periosteum cannot be adhered away from the suture lines due to the strong adherence.
109
What is the clinical appearance of an subdural haemorrhage, and who does this occur in more often?
A head injury incurs, leading to rupture of the bridging vein, usually at the point where it crosses the dura mater. Venous pooling occurs within the subdural space, between the dura mater and arachnoid mater. They can initially be unconscious or not, and after they often complain of a headache. The rate of deterioration is much slower.
Due to cortical shrinkage of the brain, there is increased pressure of the bridging veins in the elderly.
110
What is the radiographical appearance of an subdural haemorrhage - why?
Crescent shaped appearance due to blood filling one half of the hemisphere of the brain.
111
What is the clinical appearance of an subarachnoid haemorrhage?
Trauma to the head or spontaneous rupture of a blood vessel, due to aneurysm - a branch of the circle of Willis.
Blood leaks into the subarachnoid space, between the arachnoid mater and pia mater, mixing with the CSF and irritating the meninges.
It is sudden and often fatal.
112
How are subarachnoid haemorrhage’s diagnosed?
CT head imaging - the faster it is done, the greater the chance of being able to see the haemorrhage.
Lumbar puncture - if a prolonged period has passed, then haemoglobin degradation product test will be done.
113
What pathology seen in the skin can cause lumps on the scalp?
Sebaceous cysts.
Haematoma.
114
Why do superficial cuts to the scalp bleed so profusely?
The dense connective tissue inhibits the vessels from vasoconstricting, leading to an increase in blood loss.
115
Why can there be avulsion of more than one layer of the scalp when hair becomes trapped and pulled out?
The skin and epicranial aponeurosis are strongly adhered to the dense connective tissue, meaning that they all get pulled off together.
116
What is the function of the loose connective tissue of the scalp?
Allows for movements in all directions.
It contains emissary veins which drain the scalp to the dural venous sinuses.
117
Where can the spread of blood go to if the laceration is to the depth of the loose connective tissue?
It can track under the epicranial aponeurosis, under the obicularis oculi, leading to bruising over the orbits.
It can also lead to intracranial infections due to the bacteria spreading into the dural venous sinuses via emissary veins.
118
Why do deep lacerations gape, and how are they treated?
The epicranial aponeurosis pull each side of the laceration apart.
The aponeurosis must be sutured first and then the superficial structures.
119
What is the usual shape of the motor and sensory neurones?
Motor - unipolar.
Sensory - pseudounipolar.
120
What is the cephalic flexure?
The neuraxis flexing at the level of the midbrain.
121
Outline where the rostral, caudal, ventral and dorsal aspects of the brain would appear, in normal topography.
122
What is the forebrain formed of and how does it split?
It is formed of the cerebrum and the diencephalon.
It splits into the left and right hemispheres.
123
What is the diencephalon formed from, and what are their functions?
Thalamus - directs sensory information from the peripheries to the brain for perception.
Hypothalamus - endocrine function.
124
What is the function of the cerebellum and where is it found?
It is part of the CNS that is involved in co-ordination and balance.
It is found at the back of the brainstem.
125
What is the significance of the anatomical position of the foramen magnum?
It is the point at which the brainstem is found above and the spinal cord is found below.
126
Where are the cell bodies and nuclei found, within the forebrain?
Cortex of the brain - grey matter, also containing unmyelinated axons and glial (support) cells.
127
What is the function of the sulci and gyri?
To increase the surface area of the grey matter.
128
What do the central sulcus, lateral fissure and parieto-occipital sulcus split?
Central sulcus - separates the frontal lobe from the parietal lobe.
Lateral fissure - separates the temporal from the parietal and frontal lobes.
Parieto-occipital sulcus - splits the parietal and occipital lobes, can only be seen medially.
129
What is the structure and function of the corpus collosum?
It is formed of bundles of axons that allows for communication between hemispheres.
130
What separates the two lateral ventricles of the brain?
Septum pellucidum.
131
What is the function of the frontal lobe?
132
What is the function of the temporal lobe, and is there any difference between the functions in the left and right sides?
Does occur in both hemispheres, just dominant in one over the other.
133
What is the function of the parietal lobes?
Somatosensory perception.
Spatial awareness.
Body image.
134
What is the function of the occipital lobe?
Visual perception.
135
What is the function of the pre- and post-central gyri?
Pre-central = primary motor cortex.
Post-central = primary somatosensory cortex.
136
What are the functions of the 3 parts of the brainstem, and what is its overall function?
Midbrain - eye movement coordination and pupillary response to light.
Pons - feeding, sleep and consciousness.
Medulla - cardiovascular and respiratory function.
The sensory and motor pathways run up and down through the brainstem.
137
Where do the motor pathways become spinal nerves, and what from?
Explain how they control certain sides of the body.
Upper motor nerves, with their cell bodies in the primary motor cortex, descends through the brain and decussates at the level of the medullary pyramids, where they synapse onto spinal nerves.
138
What is a lower motor neurone?
The motor fibres of the spinal nerve - PNS.
139
How do cranial nerves with motor function decussate?
The upper motor neurone, from the primary motor cortex, decussate at the level of the cranial nerve nuclei.
140
If the upper motor neurone is lost, what happens to some of the cranial nerves?
They have a back-up cortical input from the ipsilateral motor cortex.
141
How can there be injury to the neurones within the forebrain or brainstem, that connect to the spinal nerves?
There can be tumours that compress the neurones during their pathway.
A stroke can occur.
142
What are the mixed, sensory, and motor cranial nerves?
State where they arise from.
143
What is the commonest cause for anosmia, and how does this occur?
Common cold or upper respiratory tract infections lead to swelling of the tissues, inhibiting the chemicals from reaching the olfactory nerves.
144
What is the olfactory mucosa?
The olfactory receptors, which are within the epithelium of the superior aspect of the nasal cavity.
145
How could a tumour cause anosmia?
A frontal lobe tumour could compress the olfactory bulb or tract.
146
What medical conditions are associated with olfactory nerve complications?
Parkinson’s disease.
Alzheimer’s disease.
147
What stimulates the generation of action potentials for the optic nerve to pass on signals?
Photons.
148
What are the clinical findings of examinations of optic nerve lesions?
149
What can some fibres of the optic tracts terminate at?
Some fibres communicate with the brainstem, giving information about light intensity to control pupil size.
Most continue on the visual pathway, to the occipital lobe.
150
How can the optic nerve be compressed?
If there is an increase in intracranial pressure, the optic nerves can be compressed against the free tentorial edge.
If there is a pituitary tumour then the optic chiasm can be compressed.
151
What is the difference in appearance of injury to the optic nerve or optic chiasm, and why?
Optic nerve - visual symptoms or blurring on the affected side.
Optic chiasm - visual disturbances in both eyes as the optic nerve neurones cross here. Bitemporal hemianopia.
152
What opening in the cranial floor do CNS III, IV and VI pass through?
The superior orbital fissure.
153
What two smooth muscles does the CN III - oculomotor nerve - supply, and what are their functions? State which afferent fibres supply which.
Sphincter pupillae - found in the iris to constrict the pupil size. Visceral afferents (parasympathetic).
Ciliary body - controls the size of the lens of the eye. Visceral afferents (parasympathetic).
154
What skeletal muscles does the CN III - oculomotor nerve - supply, and what are their functions? State which efferent afferent supply which.
All extra ocular muscles, except 2 - eye movements.
Levator palpebrae superioris - keeps the eyelid retracted.
These are supplied by the somatic (motor) afferent fibres.
155
What kind of herniation causes oculomotor nerve lesions?
Uncul (tectorial) herniation.
156
Which artery is at risk of aneurysm, causing an oculomotor nerve lesion?
Posterior communicating artery.
157
What muscle is supplied by the trochlear nerve?
Superior oblique muscle.
158
Which muscle is supplied by the abducens nerve, and what is the abnormal eye position with lesions?
Lateral rectus muscle - meaning that there is medial deviation of the eye.
159
What is the importance of the route of the abducens nerve, when considering pathology?
Compression is likely due to the upward trajectory, as it runs along the clivus.
This can lead to stretching of the CN.
160
What is the function of the cerebellar tonsils, and where are they located?
They coordinate voluntary movement of the distal part of the limbs.
They appear on the inferior aspect of the cerebellum, protruding downwards.
161
What is the function of the midline vermis and cerebellar peduncles?
Midline vermis - splits the cerebellum into left and right. Controls trunk musculature.
Cerebellar peduncles - connect the cerebellum to the brainstem.
162
What condition is optic neuritis associated with?
Multiple sclerosis.
163
What are the neurosensory cells for the optic nerve?
Cones and rods.
164
What movement of the eye is affected by a trochlear nerve injury?
Difficulty moving the eye down and out.
165
What are cranial nerve lesions?
How do they present on each side of the body?
Disease/ injury involving the nuclei of the cranial nerve, within the brainstem, or with the cranial nerve outside of the CNS.
Lesions to the cranial nerve on one side of the body will lead to palsy on that side of the body.
166
What type of conditions can cause symptoms on the opposite side of the body, why?
Injuries within the CNS, such as strokes and intracranial pressure increases.
This is because the neurones supplying the cranial nerves, within the brain are yet to decussate.
167
What are the sensory innervations of the trigeminal nerve?
The skin and tissues of the face, parts of the scalp, the surface of the eye and some deep facial structures.
Anterior 2/3rds of the tongue.
168
What deep facial structures does the trigeminal nerve supply?
Orbital structures, the nose and nasal cavity, the paranasal air sinuses and parts of the oral cavity.
169
What is the motor innervation of the trigeminal nerve?
Muscles of mastication.
170
How is the trigeminal nerve examined?
Light touch in the dermatomes of Va, Vb and Vc, on either side of the face with the patients’ eyes closed.
Ask the patient to tense the jaw and feel for the tension in the temporalis and masseter, also get the patient to wiggle jaw side to side for the pterygoids.
Corneal reflex.
171
What is the corneal reflex, and what is it testing for within the trigeminal?
Both eyes are open and touching of the cornea of one of the eyes causes both eyes to close.
The opthalamic division of CN V senses the touch, which sends impulses to the brain, stimulating the facial nerve to respond - motor (obicularis oculi, closing the eyes).
172
What are some causes of trigeminal nerve lesions?
Trigeminal herpes zoster.
Trigeminal neuralgia.
Orbital and mandibular fractures - distal branches.
Posterior cranial fossa tumours.
Brainstem infarcts/ lesions.
173
What determines where trigeminal herpes zoster will infect?
The division in which the herpes zoster virus travels down from the trigeminal ganglion determines where the virus will be seen.
174
What is trigeminal neuralgia?
Compression of the trigeminal ganglion from an aberrant blood vessel (deviated from its normal path), causing electric shock-like pain in the region of the affected division.
175
What foramina do each of the branches of the trigeminal nerve pass through?
Opthalamic - superior orbital fissure.
Maxillary - foramen rotundum.
Mandibular - foramen ovale.
176
What are the branches of the opthalamic division of the trigeminal nerve, and what are their functions?
Lacrimal - sensation of the lacrimal glands.
Frontal - gives sensation to skin around the eyes, via the supraorbital and supratrochlear nerves.
Nasociliary - sensation to the eyeball and dorsum of the nose.
177
What is Hutchinson’s sign?
Trigeminal herpes zoster where the is involvement of the tip of the nose, increasing the risk of the eyeball being involved, as there is communication via the nasocilliary branch. Scarring due to vesicle formation there leads to visual defects.
178
What are the branches of the maxillary division of the trigeminal nerve, and what are their functions?
Infraorbital nerve - runs through the infraorbital foramen, giving sensation to the lower eyelid and cheek.
Superior alveolar nerve - gives sensation to the upper jaw, teeth and the gums.
179
How can the infraorbital nerve be damaged?
Orbital blow-out fractures, where it runs through the floor of the orbit.
180
What are the branches of the mandibular division of the trigeminal nerve, and what are their functions?
Motor branch supplying the muscles of mastication.
Lingual nerve - sensation to the anterior 2/3rds of the tongue.
Inferior alveolar nerve - travels within the mandible, giving sensation to the teeth and gums of the lower jaw, and from the skin of the chin (mental nerve).
Auriculotemporal nerve - innervates the temporal-mandibular joint and the side of the head.
181
What nerve can mandibular fractures put at risk?
Inferior alveolar nerve.
182
What is the functions of the facial nerve?
Motor - muscles of facial expression and stapedius.
Parasympathetic - lacrimal, nasal and salivary glands.
Taste - anterior 2/3rds.
183
What foramen does the facial nerve pass through to emerge through the base of the skull?
Through the internal acoustic meatus and then through the stylomastoid foramen.
184
What are the 3 intra-petrous branches of the facial nerve, and what are their functions?
Greater petrosal nerve - carries parasympathetic innervation to the lacrimal and nasal glands.
Nerve to stapedius.
Chorda tympani - taste of the tongue and parasympathetic innervation of the salivary gland.
185
How can the facial nerve be damaged?
Lesions around the internal acoustic meatus.
Posterior cranial fossa tumours.
Basal skull fractures, involving the petrous bone.
Middle ear disease.
Facial nerve palsy - Bell’s palsy, Ramsay-Hunt Syndrome.
Parotid malignancy.
186
What is the function of the vestibulocochlear nerve?
Innervates the cochlear for hearing.
Innervates the vestibular system for balance.
187
What do patients present with, with a vestibulocochlear nerve injury and how can these patients be examined?
Presents with hearing loss with or without tinnitus; dizziness/ vertigo.
Tested with bedside hearing tests such as a whisper or finger rub. Can also perform a tuning fork test.
188
How can the vestibulocochlear nerve be damaged?
Vestibular schwannoma and other posterior cranial fossa tumours.
Occlusion of labyrinthine artery.
Petrous bone fractures.
189
What is the route of the glossopharyngeal and vagus nerves?
Medulla.
Run through posterior cranial fossa.
Exit through jugular foramen.
Enter into carotid sheath:
- CN IX exits carotid sheath proximally.
- CN X continues down length of neck.
190
What is the function of the glossopharyngeal nerve?
Sensation of the oropharynx/ tonsils, and the middle ear cavity.
Gives sensation and taste to the posterior 1/3rd of the tongue.
Parasympathetic innervation to the parotid gland.
Afferent nerve fibres from the carotid sinus and carotid body.
191
Why may the glossopharyngeal nerve not be classed as a purely sensory nerve?
It gives a small contribution to the muscles of the pharynx.
These innervations join with the vagus nerve to form the pharyngeal plexus.
192
What is the function of the vagus nerve?
Gives motor function to the muscles of the larynx/ pharynx, including the soft palate.
Sensation to the larynx/ laryngopharynx.
Parasympathetic innervation of gut, cardiac and airway tissues.
Sensation to the parts of the external ear.
193
What may patients present with CN X nerve lesions?
Difficulties with speech.
Changes in voice.
Difficulty swallowing.
Weak cough.
194
How can you test for CN X lesions?
Speech and cough.
Asking the patients to open their mouth and say ‘ahhh’ to see if the soft palates elevate on both sides - uvula pulled to one side if one vagus nerve is injured.
Swallowing.
195
How can you test for CN IX and X lesions?
Gag reflex - touching the oropharynx on both sides. The sensation is by CN IX and motor by CN X.
196
How can CN IX and X be damaged?
Recurrent laryngeal nerve can be damaged by thyroid pathology or surgery, as well as superior thorax/ mediastinal pathology.
Pathology of the carotid sheath.
Posterior cranial fossa tumours.
Fractures to the base of the skull, involving the jugular foramen.
Medullary brainstem lesions, such as strokes.
197
What is the common and differing routes of the accessory and hypoglosal nerves?
Common - arise from the medulla (and spinal nerves for CN XI) and run through the posterior cranial fossa. Enter into carotid sheath.
Different:
- Hypoglossal exits and travels towards the tongue. Initially through hypoglossal canal.
- Accessory exits and heads towards the posterior triangle. Initially through jugular foramen.
198
What is the function of the hypoglossal nerve?
Innervates the muscles of the tongue for movements and protrusion.
199
How is the hypoglossal nerve examined?
Movements of the tongue from side to side.
Protrusion of the tongue can lead to deviations of the tongue, towards the side innervated by the damaged nerve.
200
What are some causes for hypoglossal nerve lesions?
Surgery or pathology involving the internal or external carotid arteries.
Posterior cranial fossa tumours.
Motor neurone disease.
Ischaemia of the brainstem, where the hypoglossal nucleus lies.
201
How is the accessory nerve tested for?
Turn the head (SCM) and shoulder shrug (trapezius) against resistance.
202
What are some causes for accessory nerve injuries?
Surgery, injury or pathology involving the posterior triangle.
Posterior cranial fossa tumours.
Fractures of the base of the skull, involving the jugular foramen.
203
What do the pharyngeal arches make up, in the embryo?
The lateral walls of the embryonic pharynx.
204
What does the first pharyngeal cleft become?
The external auditory meatus.
205
What is the external ear formed from?
Swellings of the first and second pharyngeal arch.
206
What is the relationship between the sizes of the pharyngeal arches?
The first is the largest, and they get progressively smaller.
207
What is the cartilaginous bar of the first pharyngeal arch known as?
Meckel’s cartilage.
208
What does the Meckle’s cartilage give rise to?
The mandible, malleus (hammer) and incus (anvil).
209
What do the 4th and 6th arches give rise to?
The thyroid, arytenoids and cricoids.
210
What are the cranial nerves associated with each of the pharyngeal arches?
211
What does the facial skeleton arise from?
The frontonasal prominence and the first pharyngeal arch.
212
What is the muscular derivative of the first pharyngeal arch?
Muscles of mastication.
213
What is the muscular derivative of the second pharyngeal arch?
Muscles of facial expression.
214
What is the muscular derivative of the third pharyngeal arch?
Stylopharyngeus - muscle of the pharynx.
215
What is the muscular derivative of the fourth and sixth pharyngeal arch?
216
What is the derivative of the first pharyngeal pouch?
Pharyngotympanic (Eustachian) tube and middle ear cavity.
217
What is the derivative of the second pharyngeal pouch?
Palatine tonsil.
218
What is the derivative of the third pharyngeal pouch?
Inferior parathyroid.
Thymus.
219
What is the derivative of the fourth pharyngeal pouch?
Superior parathyroid.
C-cells (parafollicular) of the thyroid.
220
What are the 5 building blocks of the development of the face?
Frontonasal prominence.
Two maxillary prominences.
Two mandibular prominences.
221
What does the frontonasal prominence form?
Forehead, bridge of the nose, upper eyelids and the centre of the upper lip - philtrum.
222
What will the maxillary prominences form?
Middle third of the face, the upper jaw and most of the lip and sides of the nose.
223
What will the mandibular prominences form?
Lower third of the face - lower jaw and lip.
224
What two structures that form the face, make up the first pharyngeal arch?
The maxillary and mandibular prominences.
225
What are each of the mandibular and maxillary prominences formed from?
Mesenchyme surrounded anteriorly by ectoderm and posteriorly by endoderm.
226
What are the nasal placodes and what do they form?
Ectodermal thickenings on the frontonasal prominence that give rise to sensory structures, the nasal pits which are the future nostrils.
227
What are the nasal pits and stomodaeum separated by, and what happens to it?
A thin sheet of cells - oronasal membrane.
This disappears to form a continuous space between the oral and nasal cavities.
228
What does the merging of the medial nasal prominences form?
The medial nasal prominences merge at the midline, separating the nostrils from the mouth and forming the philtrum of the upper lip, and the primary palate.
229
How is the palate formed?
Developmental tongue drops down.
Two palatal shelves grow from each maxillary prominence, towards the midline.
These fuse with each other and the primary palate.
230
How are the nasal and oral cavities separated?
By the secondary palate.
231
How does a cleft lip form?
Failure of fusion of the medial nasal prominences and the maxillary prominences.
232
How does a cleft palate form?
When the palatal shelves do not fuse at the midline.
233
What are the causes of a cleft lip or a cleft palate?
A mixture of genetic and environmental factors.
234
How is a cleft lip or palate diagnosed?
Ultrasound scan - usually at mid-pregnancy in the anomaly scan.
If not picked up, then it is diagnosed after delivery.
235
What are the problems with a cleft lip or palate?
Difficulties with feeding and speech.
236
How are cleft lips and palates treated?
Surgery:
- Lip = around 3 months.
- Palate = around 9-12 months.
Up to then, specialist feeding techniques are shown to the mother.
237
What is the skeletal derivative of the second pharyngeal arch?
Stapes - middle ear bone.
Superior part of the hyoid.
238
What is the skeletal derivative of the third pharyngeal arch?
Inferior part of the hyoid.
239
What is the skeletal derivative of the 4th and 6th pharyngeal arches?
Laryngeal cartilages.
240
What are the abnormalities due to incomplete obliteration of the cervical sinuses?
Why do these occur?
Branchial cysts - fluid-filled cysts that lie in the anterior triangle.
Pharyngeal sinus - pits near to the ear that communicates with the skin.
Pharyngeal fistulae - communication between the skin and pharynx.
These may occur due to the incorrect obliteration of the cervical sinuses, as the second pharyngeal arch does not correctly grow ventrally over the pharyngeal clefts.
241
What can cause mal-ascent of the ears?
Fetal alcohol syndrome.
242
What are the auricular hillocks?
Evaginations of the first and second pharyngeal arches.
243
What nerves of each of the areas of skin of the frontonasal process, maxillary process and mandibular process supplied by?
Frontonasal - opthalamic nerve.
Maxillary - maxillary nerve.
Mandibular - mandibular nerve.
244
What are the muscles of the tongue formed from?
Occipital somites at the level of the hypoglossal nerve.
245
Why would the muscles of the lower face only be paralysed on one half of the face?
Pathology of the upper motor neurone supplying facial nerves that supply that side of the face, from the primary motor cortex.
The upper half of the contralateral (as has not decussated) has a back-up innervation and so is spared.
246
When would there be paralysis of a whole half of the face?
When there is pathology or injury to the facial nerve from its exit of the pons of the brainstem to its innervation of the target tissue.
This is ipsilateral as the decussation has already occurred.
247
At what spinal level do the sympathetic innervation of the head and neck exist?
T1 and T2, on the left and right.
248
Describe the route of the sympathetic innervation to the tissues of the head and neck.
From T1 and T2, the spinal nerves enter the sympathetic chain.
They they ascend into the neck to the superior and middle cervical ganglion.
They then synapse onto post-ganglionic neurones, which run with the internal and external carotid arteries.
249
Where, in relation to the carotid sheath, do the cervical ganglion lie?
Posterior and medial to the carotid sheath.
250
What is the association between the sympathetic nerves and carotid arteries?
They form a plexus around the internal and external carotid arteries.
251
What are the routes of the sympathetic with the:
- Internal carotid artery.
- External carotid artery.
Internal carotid artery - enter the eye and orbit, where they run with the ophthalmic artery and distal branches of Va.
External carotid artery - run to the sweat glands of the face and neck.
252
What is the function of the sympathetic innervation, associated with the ICA?
Innervates the dilator pupillae, to dilate the pupil.
Innervates the smooth muscles aspect of levator palpebrae superioris - superior tarsal muscle - to elevate the upper eyelid.
253
Why can spinal cord injuries lead to sympathetic dysfunction?
There is a central pathway between the hypothalamus and the sympathetic nerves exiting the spinal cord.
254
What are first, second and third order neurones, relating to the sympathetic nervous system?
1st order - within the CNS, the hypothalamic connection.
2nd order - pre-ganglionic neurones, run to and within the sympathetic chain.
3rd order - post-ganglionic neurones, that run with blood vessels.
255
What head and neck pathologies can affect the sympathetic nerves?
Categorise the order of these lesions.
Lung cancers that can invade the sympathetic trunk - 2nd order neurone lesion.
Common/ internal carotid artery dissection or aneurysm - 3rd order neurone lesion.
256
What is the clinical manifestation of Horner’s syndrome?
Partial ptosis - sympathetic innervation to the superior tarsal muscle.
Miosis - pupillary constriction.
Anhidrosis - lack of sweating on one side of the face.
Enopthalamus - apparent sinking of the eye.
257
What is the association between the pre-ganglionic parasympathetic neurone and the cranial nerves?
Their nuclei lie close to the cranial nerve nuclei.
They exit with one of 4 cranial nerves.
They synapse at the parasympathetic ganglia, which the cranial nerve runs straight through, and continue with the distal branches of trigeminal nerve.
258
Explain the difference between the parasympathetic fibres and the oculomotor nerve, and the other cranial nerves that have parasympathetic fibres.
The parasympathetic fibres run between the axons of the CN VII, IX and X.
The parasympathetic fibres run along the outside of the CN III.
259
Explain the route of the parasympathetics associated with the facial nerve, and its targets.
Cell bodies of the pre-ganglionics are found in the superior salivary nucleus.
They travel to the pterygopalatine ganglia and the submandibular ganglia, via the greater petrosal nerve and Chorda tympani, respectively.
Post-ganglionics then go and innervate:
- Pterygopalatine - lacrimal, nasal and mucosal glands.
- Submandibular - submandibular and sublingual glands.
260
Explain the basic route of the parasympathetics associated with the glossopharyngeal nerve, and its targets.
Cell bodies of the pre-ganglionics are found in the inferior salivary nucleus.
They travel to the otic ganglia.
Post-ganglionics then travel along the Vc branch of the trigeminal nerve to go and innervate the parotid gland.
261
Explain the route of the parasympathetics associated with the vagus nerve, and its targets.
Cell bodies of the pre-ganglionics are found in the dorsal motor nucleus.
They travel to ganglia that sit very close to or within the target tissue.
Post-ganglionics then go and innervate the mucous glands and smooth muscle of the respiratory and GI tract, and the cardiac muscle.
262
What are the two parasympathetic branches of the facial nerve, that are given off in the petrous bone, and what are their associated ganglia?
Greater petrosal nerve - pterygopalatine ganglion.
Chorda tympani - submandibular ganglion.
263
Explain the route of the parasympathetics associated with the glossopharyngeal nerve.
The pre-ganglionics arise from their own nuclei (inferior salivary) within the brainstem, in close proximity to the CN IX nuclei.
They exit the medulla with other axons, forming the glossopharyngeal nerve.
They all exit through the jugular foramen.
The parasympathetics then hitch-hike with the tympanic nerve, and then the lesser petrosal nerve.
They synapse onto the otic ganglion, where the post-ganglionic parasympathetics run with the auriculotemporal nerve (Vc branch), to the parotid gland.
264
How many cervical ganglia are there?
3:
- Superior cervical ganglia.
- Middle cervical ganglia.
- Inferior cervical ganglia.
265
What is the only cranial nerve to arise from the dorsal aspect of the midbrain?
Trochlear nerve.
266
What foramen does the facial nerve pass through?
Internal acoustic meatus.
267
How does the consensual light reflex differ from the direct light reflex?
There is communication between the pre-tectal nucleus on one side of the body to the edinger-westphal nucleus on the other side, for the pre-ganglionic on the opposite side of the body to innervate the sphincter pupillae of the iris. This causes the pupil on the opposite side of the body to constrict.
268
What is the relationship between the parasympathetic ganglion and the cranial nerve, associated with that parasympathetic neurone?
The specific cranial nerve passes through the ganglion, without synapsing.
269
Where are the cell bodies of the sympathetic pre-ganglionic neurones found?
Lateral horn of the grey matter.
270
What is the otic ganglion located?
Within the infratemporal fossa.
271
What is tinnitus?
Sounds ‘perceived’ from an external source - ringing, humming, whistling, etc.
272
Label the following diagram.
273
What branch of the glossopharyngeal nerve supplies the medial surface of the tympanic membrane and middle ear cavity?
Tympanic nerve.
274
What is the self-cleaning function of the external acoustic meatus?
Desquamatisation - dead squamous epithelium - migrate laterally out from the tympanic membrane.
275
How are the ears moved in adults and children for otoscaopy?
Adults - outwards, up and back.
Children - down and back.
276
What is tympanosclerosis?
Hardening of the tympanic membrane giving the appearance of white plaques, which is from healed trauma, that give no hearing deficits.
277
What are the muscles in the middle ear, and what are their functions?
Stapedius and tensor tympani.
They contract if there is excessive vibration from loud noise of the ossicles, decreasing the perception of the loudness of the noise.
278
What is hyperacusis, and what is it commonly due to?
Ineffective actions of the stapedius and tensor tympani to decrease the vibrations and loudness of the noises perceived, leading to sensitivity to loud noise.
It is most commonly due to facial nerve lesions (nerve to stapedius).
279
Why is there more commonly pathology of the middle ear canal in children than adults?
The pharyngotympanic tube is shorter, wider and more horizontal in children making passage for infections from the nasopharynx easier.
The adenoids in children are larger than in adults and so are more prone to obstructing the Eustachian tube.
NOTE: acute otitis media is much more common in children and infants.
280
How are the semicircular canals arranged?
The anterior, posterior and horizontal/ lateral semicircular canals are at 90 degree orientations to each other.
281
What is found in the utricle and saccule that can displace to cause pathology?
Otoliths - calcium carbonate crystals.
282
What causes the generation of action potentials in the vestibular system?
Head movements causes movement of fluid within the semicircular canals, utricle and saccule.
Fluid shifts the gelatinous matrix - cupula and otolithic membrane.
This causes the stereocilia to bend, generating action potentials down CN VIII.
These signals are perceived as a sense of position and balance, in the cerebellum, to cause head and postural adjustments.
283
What is the vestibuloocular reflex?
The movement of the stereocilia in the ear that generates action potentials, which feeds into the reflex controlling the eye position.
This involved the medial-longitudinal fasciculus.
284
Where are the stereocilia within the cochlear?
Spiral organ of corti.
285
Describe the physiology of hearing.
286
Where is the blood accumulation in a pinna haematoma, and how can a cauliflower ear develop from this?
Subperichondrial - blood accumulates between the cartilage and perichondrium due to shearing of blood vessels in the perichondrium.
If the blood is not drained then the cartilage is deprived of blood and the pressure from the haematoma against the cartilage causes fibrosis.
287
What organisms often cause acute otitis externa?
Staphylococcus aureus and pseudomonas aeruginosa.
288
What are the risk factors for developing acute otitis externa?
Injury to the external auditory meatus.
Swimming and warm weather.
Skin problems such as eczema.
289
What are the symptoms and treatment of acute otitis externa?
Symptoms - otalgia, custard-like discharge that smells, and hearing loss.
It is treated with topical antibiotics (ear drops), with steroids if severe.
290
What is necrotising otitis externa?
Complication of acute otitis externa where the infection travels deeper, causing osteomyelitis of the temporal bone and base of the skull.
291
What is the causative organism of necrotising otitis externa?
Pseudomonas aeruginosa.
292
What are the risk factors for necrotising otitis externa?
Male, diabetic, immunocompromised and older age (>65).
293
What are the symptoms of necrotising otitis externa, and how is it treated?
Symptoms - severe otalgia, purulent discharge, worsening acute otitis externa, hearing loss, and cranial nerve involvement.
Treatment - IV antibiotics (can be oral with topical drops), and analgesia.
294
What is the presentation with somebody with acute otitis media?
Babies and young children (up to 4), that has otalgia (often seen pulling their ear), a fever and red/ bulging tympanic membrane.
295
What is the treatment for acute otitis media?
It is often self-limiting, lasting 3 days to a week, so nothing.
Analgesia.
Back-up antibiotic prescription.
296
What are some complications of acute otitis media?
Tympanic membrane perforation - instant pain with blood discharge.
Facial nerve involvement.
Mastoiditis.
Intracranial complications - meningitis, sigmoid sinus thrombosis, brain abscess.
297
What is the pathophysiology of a patient with otitis media with effusion?
Infant or child with pharyngotympanic dysfunction that causes negative pressure and fluid accumulation within the middle ear.
It decreases the mobility of the tympanic membrane and ossicles causing hearing loss.
The child is otherwise healthy.
298
What is the presentation of cholesteatoma?
Red lesion at the attic (pars flaccida) of the tympanic membrane.
Foul-smelling discharge.
Progressive hearing loss.
Secondary symptoms due to the destruction of other tissues.
299
What causes cholesteatoma and how is it treated?
It can be due to chronic middle ear infections, or congenital.
Treated surgically - mastoidectomy - but can cause facial nerve damage.
300
How do middle ear infections cause cholesteatoma?
Accumulation of fluid in the middle ear canal pulls to tympanic membrane inwards, forming a retraction pocket.
This allows for dead keratinised stratified squamous epithelium to accumulate within the pars flaccida.
Thus epithelium can then grow into the middle ear and beyond, destroying subsequent structures.
301
What is the Dix-hallpike manoeuvre?
Patients head is tilted 45 degrees whilst sat up.
They are then lowered to 20 degrees below the table and held there for up to one minute to see nystagmus - uncontrolled movement of the eyes.
It is a diagnostic test for benign paroxysmal positional vertigo.
302
What causes benign paroxysmal positional vertigo?
A displaced otolith in the posterior semicircular canal, when movement of this otolith occurs, there is perception of movement when none has occurred.
303
What is the Epley manoeuvre?
A series of positional changes to move the otolith back into the utricle or saccule to treat BPPV.
304
What is the presentation and treatment of sudden sensorineural hearing loss?
Sudden unilateral hearing loss, within 3 days.
Treated by immediate referral to ENT for early steroid treatment.
305
Who is normally effected by otosclerosis, and what do they experience?
Females, starting at teenage to 20s.
They have progressive conductive hearing loss that starts unilateral and ends bilateral, often with tinnitus.
306
What is the treatment for otosclerosis?
Hearing aids and surgery - replacing stapes with prosthesis.
307
What is an acoustic neuroma?
A benign slow growing posterior cranial fossa tumour of the Schwann cells in the vestibular component of the vestibulocochlear nerve, that can compress other structures due to increasing size.
308
What are the signs and symptoms of acoustic neuroma?
309
How are acoustic neuromas diagnosed and treated?
MRI.
Surgery and radiation.
310
Describe Rinne’s test.
311
Describe Weber’s test.
312
What is the name of the thin section of the ethmoid bone?
Lamina papyracea.
313
What increases the strength of the lamina papyracea?
The anterior, posterior and middle ethmoid air cells.
314
What is the drawback of the ethmoid air cells?
They can become infected, forming acute sinusitis.
They can break through the thin lamina papyracea, tracking into the orbit, forming orbital cellulitis.
315
What is transmitted through the optic canal, superior orbital fissure and inferior orbital fissure?
316
What is the function of the outer layer of the eyeball?
Sclera gives structure to the eyeball, and continues posteriorly as the dural sheath, protecting the optic nerve. It also provides attachments for extra-ocular muscles.
Anteriorly, the sclera is the cornea, which refracts light to improve visual acuity.
317
What covers the sclera, and what is its anatomy?
A thin transparent layer of cells called the conjunctivae.
It extends up to the edge of the cornea - limbus - and reflects back covering the internal surface of the upper and lower eyelids. Blood vessels run trough the conjunctivae.
318
What are some autoimmune conditions associated with uveitis and what is the treatment of it?
Ankylosing spondylitis and inflammatory bowel disease.
Referral to ophthalmology for corticosteroid treatment.
319
What is the pigmented epithelial layer of the retina, and what is its function?
A layer of cells that contain melanin which help to absorb scattered light to reduce reflection, allowing images to be focussed onto the retina.
320
What is the macula?
What is its appearance on fundoscopy?
An area of the retina which contains a high proportion of cones, in which an object in the visual field falls if gazed directly at.
It is a slightly darker area of the retina.
321
What is the centre of the macula?
Fovea - only photoreceptors contained are cones.
322
What causes colour vision deficiency?
Who does it affect more?
An absence or dysfunction of on of the red, green or blue sensitive cones.
It is more commonly seen in males.
323
What is the difference between the vitreous and aqueous humour?
Vitreous is jelly-like and found posterior to the lens.
Aqueous is a transparent liquid found anterior to the lens, that supports the shape of the eyeball.
324
What is the irido-corneal angle?
The space between the anterior surface of the iris and the posterior extremity of the cornea.
325
What is tonometry?
Directing a brief puff of air against the cornea.
Used to measure the intraocular pressure.
326
What condition is acetazolamide used in and why?
Closed-angle glaucoma.
It is a diuretic that reduces the amount of aqueous humour produced.
327
Why are muscarinic eye drops used for acute angle-closure glaucoma?
They cause pupillary constriction that helps to open the irido-corneal angle, improving the drainage of aqueous humour.
328
Who is most at risk of closed-angle glaucoma?
Long-sighted middle aged or elderly people.
People with shallow anterior chambers.
329
What is the iris?
A thin contractile diaphragm, containing the sphincter- and dilator- pupillae, and gives rise to the colour of the eye.
330
What structure is the lens?
Transparent and biconvex.
331
What nerve innervates the ciliary muscle?
The parasympathetic fibres, associated with the oculomotor nerve.
332
How is an orbital blowout factor managed?
CT of the orbit.
Avoid blowing nose, valsava manoeuvres and driving (diplopia).
Conservatively for 1 week to reduce the swelling to resolve the enophthalmus and diplopia (entrapment).
Surgical repair if symptoms persist after a week or 2.
333
What can be seen on a CT scan of an orbital blowout fracture?
Orbital contents prolapsing and bleeding into the maxillary sinus.
Soft tissues and muscles trapped in the fracture site.
334
What is the orbital septum and what is its function?
A thin fibrous sheet originating from the orbital rim, that is continuous with the tarsal plate (dense connective tissue).
It acts as a barrier against infection spread, from the superficial eye, into the orbital cavity.
335
What are potential complications of post-septal (orbital) cellulitis?
How is it treated?
Sight-threatening due to increased pressure, compressing the optic nerve.
Can spread intracranially via the superior and inferior ophthalmic veins, causing cavernous sinus thrombosis or meningitis.
It is treated with IV antibiotics.
336
What are the structures that become infected, in an orbital cellulitis?
The orbital tissues and fat.
Extra-ocular muscles.
337
What does the levator palpebrae superioris insert into?
Orbital septum and tarsal plate.
338
What are meibomian glands, and what are their functions?
Glands within the tarsal plate, located at the back of the eyelid.
Modified sebaceous glands that provide a thin layer of tear film that prevents tear evaporation and spillage over the lid.
339
What glands are associated with the lash follicle?
Sebaceous glands.
340
What is a stye, its cause and treatment?
341
What is a meibomian cyst, its cause and treatment?
342
What is the appearance, cause and treatment of blepharitis?
Inflammation of the eye lid margin, with crusting, dry eyelids that can be red and swollen.
Multifactorial cause - staphylococcus, meibomian gland dysfunction, etc.
Treated with a warm compress and regular cleaning of the eyelid to remove any blockages.
343
What are the layers of the tear film?
Meibomian glands producing oily secretions.
Lacrimal gland producing watery secretion.
Goblet cells in the conjunctiva secreting mucus.
344
What is the blinking reflex?
When the cornea becomes dry, the eyelids carry a film of fluid over the cornea, and sweep any dust or foreign material into the medial angle of the eye to be removed.
345
What is the lacrimal apparatus?
The secretions from the lacrimal gland then enters the excretory ducts of the lacrimal gland.
The watery secretions enter the lacrimal punctum and then into the lacrimal canaliculi.
It then drains into the lacrimal sac, then into the nasolacrimal duct.
The fluid then drains into the inferior meatus of the nasal cavity.
346
What is epiphora?
Overflowing of tears over the lower eyelid, due to obstruction to drainage - infection, injury or stenosis.
347
What is the eyeball maintained in its position by?
Suspensory ligament.
6 extra-ocular muscles.
Orbital fat.
348
What can cause proptosis/ exophthalmos?
Retro-orbital (retrobullar) haemorrhage.
Grave’s disease.
349
How is retrobullar haemorrhage treated?
Lateral cantholysis - lateral canthus of the eye is cut to relieve fluid pressure behind the eye.
350
What is the difference in presentation between different causes of conjunctivitis?
Always an uncomfortable, gritty feeling of the eye.
Viral - watery discharge.
Bacterial - thicker, purulent discharge.
Allergic - red, itchy and leaky eye that is bilateral (Hay fever).
351
What is the limbus?
The junction between the sclera and cornea.
352
Where do the central retinal artery and vein run?
Through the middle of the optic nerve.
353
What are some corneal injuries, what is the body’s adaptation to this, and how can they be diagnosed?
Abrasions, foreign bodies and ulcers that cause painful red eyes.
The outer epithelial layer of the cornea is constantly undergoing mitosis so easily regenerates if damaged, so providing it is superficial injury, then no lasting damage occurs.
An orange dye (fluorescein) is added and a blue light is shone, where any injury will show up as green.
354
What is keratitis?
Inflammation of the cornea, which can be sight threatening.
355
What is scleritis?
Inflammation of the sclera that causes intense pain and has a risk of rupturing the sclera, due to thinning of the sclera.
It can be sight-threatening.
356
What is the presentation of uveitis, and how it treated?
Red appearance of the eye that is painful, which is made worse with high light intensity due to iris constriction.
Treated with anti-inflammatories and steroids.
357
What is the production and drainage of aqueous humour?
358
What causes the narrowing of the irido-corneal angle in acute glaucoma?
The iris being pushed forward.
359
What is the normal optic cup proportion and what causes this to increase in glaucomatous eyes?
1/3rd.
Death of the axons increases the proportion of the optic disc that is cupped.
360
What is macula degeneration?
Degradation of the macula, leading the thinning and atrophy.
It can be dry or wet - where bleeding occurs.
It results in a gradual loss of central vision, that is usually bilateral.
361
What is the blood supply to the retina?
Central retinal artery (a branch of the ophthalmic artery).
Anterior and posterior ciliary arteries from the underlying choroid layer.
The retina required both circulations to function properly.
362
What is central retinal artery occlusion, its presentation and presentation on ophthalmoscopy?
An embolic occlusion within the central retinal artery.
It is sudden loss of vision in one eye that develops over a few seconds and is painless.
The underlying choroid layer remain perfused but insufficient for the retina, causing ischaemia. This makes the retina appear pale, accentuating the macula, forming a cherry-red spot.
363
What is the pathophysiology of cataracts?
Degradation of proteins within the lens of the eye causes clouding which scatters the light.
This means it is not focussed on the macula, so visualisation is blurry.
364
What is the treatment of cataracts?
Surgical removal of the lens and replacement with a prosthesis.
365
How is light refracted to concentrate against the macula of the retina?
The conjunctiva, cornea, lens and aqueous/ vitreous humour refract the light.
366
How does phototransduction occur?
Photons are fired at the cones or rods, generating action potentials.
These action potentials are propagated down the retinal ganglion cells (axons).
These retinal ganglion cells collect at the optic disc, forming the optic nerve,
The action potentials propagate down the optic nerve to the occipital lobe to be interpreted.
367
How is visual acuity measured, and what is the meaning of the outcome?
Snellen chart - reading a set of letters that are increasingly smaller, one eye at a time, 6m away. Glasses are worn if they normally wear glasses.
6:6 - first 6 represents 6m away. Second number shows their score. Lower the score, the better the acuity.
368
How can transparency diseases decrease visual acuity and how is this tested for?
Cataracts or vitreous haemorrhage that inhibits correct refraction.
Tested using the red reflex using ophthalmoscope, as the light reflects back.
369
What can some refractive causes of decreased visual acuity, anterior to the retina be?
370
What can leukocoria be a sign of?
Retinal blastoma - ocular malignancy, seen in children.
371
Label a retinal artery, retinal vein, optic disc and macula on the following.
372
What is the adaptation for having two eyes?
Stereoscopic vision - depth perception.
Wider field of vision.
373
What is the conjugate gaze?
Where the visual axes of both eyes are aligned and move together.
This means that the point of fixation is equal in both eyes.
Two images reaching the visual cortex can be fused and perceived as one.
374
What is the point of fixation?
The point at which the light is concentrated on the retina.
If it is central vision then it is on the macula.
375
What are the different types of diplopia, why do they occur, generally?
Seeing two images:
- Side-by-side.
- Vertical.
- Diagonally.
The point of focus is different on each area of the retina, so the brain is unable to fuse the images.
376
What is the primary resting gaze, and how does this relate to the different axes?
Primary resting gaze is where the position of the eyes is straight ahead, at rest, due to the equal and opposite actions of the extra-ocular muscles.
The orbital axes is at an acute angle to the visual axes.
377
When is the superior rectus muscle a dominating muscle, and in what action is this?
When the eye is positioned laterally, the superior rectus muscle is the dominant elevator.
378
When is the inferior rectus muscle a dominating muscle, and in what action is this?
When the eye is positioned laterally, the inferior rectus muscle is the dominant depressor.
379
When is the superior oblique muscle a dominating muscle, and in what action is this?
When the eye is positioned medially, the superior oblique muscle is the dominant depressor.
380
When is the inferior oblique muscle a dominating muscle, and in what action is this?
When the eye is positioned medially, the inferior oblique muscle is the dominant elevator.
381
What is the origin of the rectus muscles?
Common tendinous origin - annulus of Zinn.
382
What is the route of the superior oblique muscle?
Originates from the sphenoid and passes through the fascial pulley, the trochlear, and inserts on the lateral, posterior, superior aspect of the sclera.
383
What is the route of the inferior oblique muscle?
It originates from the maxillary bone and inserts onto the inferior, lateral, posterior aspect of the sclera.
384
What do the following mean:
- Strabismus.
- Esotropic.
- Hypertropic.
Strabismus - eye deviation.
Esotropic - medial deviation.
Hypertropic - superiorly deviated.
385
What are the common causes of strabismus in children in adults?
Children can form ocular misalignment in infancy, or it can be congenital.
Adults form ocular misalignment due to acquired pathology:
- Neuromuscular junction defects, e.g., myasthenia gravis.
- Extra-ocular muscle fibrosis or teathering.
- Lesions to the nerves supplying the extra-ocular muscles, CNs III, IV, VI.
386
What can be the cause of trochlear nerve injuries?
Minor head trauma.
Space-occupying lesion, such as a tumour.
Microvascular ischaemia, e.g. diabetes or hypertension.
387
What can be the cause of an oculomotor nerve injury, and how can the causes present differently?
Space-occupying lesion.
Posterior communicating artery aneurysm.
Raised intra-cranial pressure.
Microvascular ischaemia - this will be pupil-sparing as the parasympathetics are not involved.
388
What are the causes of an abducens nerve injury?
389
What are the clinical features of a trochlear nerve injury?
Elevated and adducted eye.
Vertically displaced diplopia.
Worsening diplopia when walking down stairs or reading due to looking down - superior oblique is lost and so the angle difference between the visual axes increases.
Possible head tilt to compensate for the loss of intortion.
390
What are the clinical features of an occulomotor nerve injury?
Severe ptosis.
Blown pupil (if not microvascular).
Pupil positioned down and out (as lateral rectus and superior oblique are spared).
391
What are the clinical features of an abducens nerve injury?
Pupil positioned medially.
Side-by-side diplopia.
Worsening diplopia on horizontal gaze, towards the affected eye.
392
How many teeth does an adult have, and how many of each are seen in each ‘quarter’ of the mouth?
32 teeth:
- Central incisor.
- Lateral incisor.
- Canine.
- 2 pre-molars.
- 3 molars; posterior molar is the wisdom tooth.
393
What are the different types of intrinsic muscles of the tongue, and what is the nerve supply?
What makes them intrinsic muscles?
4 paired muscles - 2 longitudinal, 1 transverse and 1 vertical.
Hypoglossal nerve.
They have no tendinous or bony origin, they are bound to other muscles.
394
What are the extrinsic muscles of the tongue and what are they innervated by?
Hypoglossal nerve:
- Genioglossus.
- Hypoglossus.
- Styloglossus.
Vagus nerve:
- Palatoglossus.
395
Where is the submandibular gland found, and what are the borders for this structure?
Submandibular triangle:
- Anterior = anterior belly of digastric.
- Posterior = posterior belly of digastric.
- Superior = mandible.
396
What are the borders of the parotid gland?
397
What does the stensen duct drain, originate from, pass through and open to?
Drains the parotid gland.
Originates from the anterior surface of the parotid gland.
Passes through the masseter and buccinator.
Opens near the second upper molar.
398
How many excretory ducts does each lingual salivary gland have - what are they called?
Have 8-20 ducts per gland - the rivinus ducts.
399
What salivary glands do most salivary stones from in and why?
In general, why do they form?
Submandibular gland - concentration of calcium is double that of the parotid gland.
Dehydration and reduced salivary flow.
400
What is a peritonsillar abscess, why does it form, and what are the symptoms?
A bacterial infection and accumulation of pus that occurs in tissues around the tonsils, often due to an (partial or) untreated tonsillitis, or arises by itself via aerobic or anaerobic bacteria.
They have severe throat pain, fever, bad breath, drooling, and difficulty opening the mouth.
401
What does the nasopharynx contain?
The adenoid tonsils.
Pharyngotympanic tube.
402
What do the palatine tonsils lie between?
The palatoglossal arch and the palatopharyngeal arch.
403
What are the 3 longitudinal muscles that elevate the larynx and pharynx, and why do they do this?
Stylopharyngeus, palatopharyngeus and salpingopharyngeus.
They do this to shorten the distance that food and drink has to move to prevent aspiration.
404
What is the origin, insertion and nerve supply of the stylopharyngues?
Origin - styloid process.
Insertion - posterior border of the thyroid cartilage.
NS - glossopharyngeal nerve.
405
What is the origin, insertion and nerve supply of the palatopharyngeus?
Origin - hard palate.
Insertion - posterior border of the thyroid cartilage.
NS - pharyngeal branch of the vagus nerve.
406
What is the origin, insertion and nerve supply of the salpingopharyngeus?
Origin - cartilaginous part of the eustachian tube.
Insertion - palatopharyngeus muscle.
NS - pharyngeal branch of the vagus nerve.
407
What are the 3 circular muscles that constrict the walls of the pharynx when swallowing?
What are their nerve supply?
Superior pharyngeal constrictor.
Middle pharyngeal constrictor.
Inferior pharyngeal constrictor.
Innervated by the vagus nerve.
408
What is the origin and insertion of the pharyngeal constrictors?
Superior pharyngeal constrictor - pterygomandibular raphe.
Middle pharyngeal constrictor - hyoid bone.
Inferior pharyngeal constrictor:
- Thyropharyngeal = thyroid cartilage.
- Cricopharyngeal = cricoid cartilage.
All insert into the pharyngeal raphe.
409
Where is a pharyngeal pouch most commonly seen, and what is it usually due to?
Seen at the Killian dehiscence.
Due to:
- Failure of the upper oesophageal sphincter to relax.
- Abnormal swallowing timing.
- Increased pressure in the laryngopharynx.
410
What is the pharyngeal plexus?
Located on the middle constrictor muscle surface, formed of the vagus, glossopharyngeal and cervical sympathetic nerves.
411
Describe the pharyngeal phase of swallowing.
412
What does the oral cavity begin and extend to?
Begins at the oral fissure, which is bound by the lips.
Extends posteriorly to the oropharyngeal isthmus - opening bound by anterior and posterior pillars, soft palate (superiorly) and the superior tongue.
413
What is the tongue covered by - surface of the tongue?
Mucous membrane - squamous epithelium.
414
What is the sensation of the pharynx?
Nasopharynx - maxillary branch of trigeminal.
Oropharynx - glossopharyngeal nerve.
Laryngopharynx - vagus nerve.
415
What can cause a cranial nerve IX or X lesion?
Medullary infarction.
Basal skull fracture, involving the jugular foramen.
416
What is the oral phase of swallowing?
417
What is the oesophageal phase of swallowing?
418
Identify the frontal, ethmoid air and maxillary sinuses on the facial X-ray.
State what the black line is pointing to and why.
Increased fluid level due to blood pooling here as there is an orbital blowout fracture.
419
Identify the maxillary sinus ostium, the middle conchae and middle meatus.
What is circled in red?
Ethmoid air cells.
420
On a CSF sample with blood, what is seen?
Halo sign.
421
How does CSF reach the nasal cavity in a basilar skull fracture?
Rupture of the dura and arachnoid leads to CSF in the arachnoid layer leaking into the nasal cavity, through the fracture site.
422
Which lymph nodes would be swollen in a patient with tonsillitis?
Jugulodigastric lymph nodes.
423
How are peritonsillar abscesses managed?
Fluid and anti-pyretics with analgesia, for supportive.
Aspirate/ incise the abscess and penicillin antibiotics given (streptococcus pyogenes).
424
Why is epistaxis common in younger children and older patients?
Younger children - visible trauma, such as picking their nose.
Older patients - nasal mucosa dries up so more friable, and often are on blood thinners so the bleeding is more noticeable.
425
Why is the sphenopalatine epistaxis more worrying?
There is higher pressure in this so greater bleeding.
It is a posterior bleed which is much harder to pack and control.
Blood can enter the oropharynx and be swallowed which can lead to vomiting, increasing the pressure, causing more bleeding, as well as further decreasing the ECF.
426
What does the nasal cavity run from and to?
Runs from the nares to the choanae.
427
What is the function and location of the vestibule?
It is found at the entrance to the nasal cavity.
It is formed of stratified squamous epithelium and has nasal hair, sweat glands and other features of skin.
It prevents foreign bodies and infectious organisms from entering.
428
What is the roof and floor of the nasal cavity?
Roof - sphenoid sinus, ethmoid bone, frontal sinus and nasal bones.
Floor - palatine bone (more posterior) and maxilla (more anterior).
429
What forms the lateral wall of the nasal cavity and what are the functions?
3 conchae, which get bigger as you go down - superior, middle and inferior.
The function of these is to slow the flow of air down and increase the surface area so there is greater humidification.
3 meatuses - superior, middle and inferior, which are all related to the conchae - drainage of the paranasal air sinuses and nasolacrimal duct.
430
What forms the medial wall of the nasal cavity?
Septal cartilage.
Perpendicular plate of the ethmoid bone.
Vomer bone.
431
Which structure may undergo avascular necrosis in a septal haematoma and how is it treated?
Why?
Septal cartilage.
Drainage of the haematoma to prevent saddle nose deformity and abscess formation, with packing of the nose to repose the perichondrium to the septal cartilage.
432
How long after fracture will re-setting of the nasal bone fracture be done by A&E doctors, before referral to ENT?
3 hours.
433
What are the common symptoms of a nasal bone fracture?
Deformity of the nose.
Swelling around the nose.
Epistaxis.
Anosmia due to shearing of the delicate olfactory nerves at the cribiform plate.
CSF leak.
434
What are the 5 arteries of the medial wall of the nasal cavity, and where do they arise from?
Ophthalmic artery gives rise to:
- Anterior ethmoid artery.
- Posterior ethmoid artery.
Maxillary artery gives rise to:
- Greater palatine artery.
- Sphenopalatine artery.
Superior labial artery (from the facial artery).
435
What is the arterial supply to the lateral wall of the nasal cavity?
Anterior ethmoid artery.
Posterior ethmoid artery.
Sphenopalatine artery.
436
What are the nervous supplies to the nasal cavity?
Ophthalmic and maxillary branch of the trigeminal nerve.
437
What can cause nasal polyps, and who is it most commonly seen in?
Chronic rhinitis.
Aspirin insensitivity.
Cystic fibrosis.
Males (2:1), over the age of 40. They are usually bilateral.
438
What is post-nasal drip?
Rhinorrhoea that drips onto the larynx, irritating the vocal cords, causing a chronic cough.
439
What are the different causes and treatments of infective and allergic rhinitis?
Infective;
- Viruses, such as coronaviruses and rhinoviruses.
- Fluid and paracetamol.
Allergic;
- Hypersensitivity to pollen, animal fur, dust, etc.
- Intranasal antihistamines, then oral antihistamines and then daily nasal steroids.
440
What paranasal air sinuses drain into the middle meatus?
Frontal sinus.
Maxillary sinus.
Anterior ethmoid sinus.
Middle ethmoid sinus.
441
What drains into the inferior meatus?
Nasolacrimal duct.
442
Where does the sphenoid sinus drain?
Into the spheno-ethmoid recess.
443
What do the paranasal air sinuses drain through to get to their middle meatus, and spheno-ethmoid space?
Small channels called ostia.
444
What is the innervation of the different paranasal air sinuses?
Va - frontal, ethmoid and sphenoid.
Vb - maxillary.
445
Label the following diagram.
446
What is the pathophysiology of acute sinusitis?
Viral upper respiratory tract infection spreads to the sinus.
Inflammation of the respiratory mucosa causes swelling, reduced cilia movement and increased secretions.
Ostia become blocked.
Fluid accumulated in the sinus, increasing the pressure causing pain.
Secondary bacterial infection can occur.
447
What are the symptoms of acute sinusitis?
How is it treated?
Blocked nosed.
Rhinorrhoea - can be green/ yellow discharge.
Pyrexia.
Headache/ facial pain that is worse leaning forward or pressure applied.
Conservatively as almost always from recent viral URTI.
448
What makes a bacterial sinusitis infection more likely?
Symptoms without improvement for over 10 days.
Discoloured or purulent nasal discharge.
Fever greater than 38 degrees Celsius.
Severe local pain.
Symptoms that worsen after initial improvement.
449
What are the functions of the larynx?
Ventilation - moving air in and out of the lungs.
Airway protection - preventing food/ fluid entering the airways.
Cough reflex - rapidly expel material entering the airway.
Aiding phonation.
450
What is the start and end of the larynx?
Laryngeal inlet to the inferior aspect of the cricoid cartilage at C6.
451
What are the cartilaginous and membranous structures that form the laryngeal skeleton?
Hyoid - suspends the larynx, not part of the larynx itself.
Thyrohyoid membrane, which connects the hyoid bone to the thyroid cartilage.
Thyroid cartilage.
Arytenoid cartilages.
Cricothyroid membrane.
Cricoid cartilage.
Cricotracheal membrane.
452
What are the ligaments of the cricotracheal and cricothyroid membranes?
The thickened aspect of the membranes, in the middle.
453
What are the structures of the thyroid, arytenoid and cricoid cartilages?
Thyroid - superior and inferior horns, laryngeal prominence and lamina.
Arytenoid - pyramidal.
Cricoid - signet ring, bigger at the back.
454
How do we find the cricothyroid membrane?
Find the laryngeal prominence and descend down.
Spongy bit that can be palpated between the thyroid and cricoid cartilages.
455
What do the true vocal cords run between?
Arytenoid cartilages to inner surface of the thyroid cartilage.
456
What are the different synovial joints of the larynx and what are their functions?
Thyroid-cricothyroid - allows the thyroid cartilage to pivot forward, increasing the tension of the vocal cords for higher pitched sounds.
Cricoid-arytenoid - adduction and abduction of the true vocal cords.
457
What is the framework of the laryngeal inlet?
458
What forms the aryepiglottic fold, the false vocal cord and true vocal cord?
AF - free upper border of the quadrangular membrane.
FVC - free lower border of the quadrangular membrane, the vestibular ligament.
TVC - free upper border of cricothyroid membrane, the vocal ligament.
459
What are the divisions of the larynx, and what do they run from and to?
Supraglottis - epiglottis to and including the false cords.
Glottis (narrowest part) - below false cords to true cords and 1 cm below.
Infraglottis - below the glottis to lower boundary of the cricoid cartilage.
460
What is the colour difference between the true vocal cords and the rest of the larynx, why?
Lighter in colour, much paler.
Stratified squamous epithelium protects from air abrasion, but the pink colour is pseudostratified columnar epithelium.
461
What are two methods of viewing the vocal cords, and how do you orientate yourself?
Flexible nasendoscopy.
Endotracheal tube.
The point of the rima glottidis points anteriorly.
462
What are the two main actions of the intrinsic laryngeal muscles, and how do these occur?
Alter the size and shape of the laryngeal inlet - muscles within the aryepiglottic fold contract to narrow the inlet and flatten the epiglottis.
Alter the tension and position of the true vocal cords - muscles acting on the arytenoid cartilages.
463
What is the protective function of the tongue to the larynx when swallowing?
Pushes against the hard palate, pushing the epiglottis down, covering the laryngeal inlet.
464
What are the functions of the posterior cricoarytenoid muscles?
Abduction of the vocal cords when breathing.
Adduction of the vocal cords when swallowing.
465
How does the position of the vocal cords produce sound and how can the position affect the different sounds?
Vocal cords are closely adducted with a small gap for air to be forced through, vibrating the cords (mucosal wave) and then the air.
Taught cords - high-pitched sounds.
Less taught - low-pitched sounds.
466
How does the cricothyroid muscle affect phonation and what is it innervated by?
Tilts the thyroid cartilage forward, increasing the tension in the vocal cords for higher pitched sounds.
Innervated by the external superior laryngeal nerve.
467
What are the branches of the vagus nerve that innervate the larynx?
Superior laryngeal nerve:
- Internal branch = sensory to supraglottis and glottis (with vocal cords).
- External branch = motor to cricothyroid muscle.
Recurrent laryngeal nerve = motor to intrinsic laryngeal muscles. Sensory to infraglottis.
468
What artery does the external superior laryngeal nerve run in close proximity to?
Superior thyroid artery.
469
What do the recurrent laryngeal nerves run in?
Tracheo-oesophageal grooves.
470
What are the symptoms and position of the vocal cord in the unilateral recurrent laryngeal nerve lesion?
Hoarse voice.
Weak/ ineffective cough.
Paramedian position.
471
What are the symptoms and position of the vocal cord in the bilateral recurrent laryngeal nerve lesion?
Significant airway obstruction leads to difficulty breathing, due to a narrowed rima glottis.
Both paramedian positions requires immediate surgery.
472
Why is there voice loss with laryngitis?
The true vocal cords are swollen and so do not come together effectively.
473
What is laryngeal oedema most commonly due to?
Anaphylactic shock.
474
How long can nasogastric tubes be in place for, and what should be done by the patient whilst one is being inserted?
Why?
Up to 6 weeks.
The patient should swallow - elevation of the larynx, narrowing and closing over by the epiglottis, reducing the risk of entering the respiratory tract.
475
What is done to confirm correct placement of NG tubes?
Aspiration to conform the pH is less than 5.5.
Chest X-ray.
476
Why may NG tubes be inserted?
To temporarily deliver liquefied food.
Drain/ empty the stomach of excess gas and fluid.
477
What nerve can be affected by an aortic arch aneurysm?
Left recurrent laryngeal nerve.
478
Where does the posterior ethmoid sinus drain into?
Superior nasal meatus.
479
Describe the cough reflex.
480
What is the thyroid isthmus located anterior to?
Tracheal rings.
481
What forms the inferior border of the posterior triangle?
Middle-third of the clavicle.
482
What intracranial complication can result from sinusitis - how?
Cavernous sinus thrombosis.
Venous anastomoses draining the paranasal air sinuses, into the cavernous sinus.
483
Why does Grave’s disease cause bilateral lid retraction?
Increased expression of noradrenaline receptors on the superior tarsal muscle.
484
What is the relationship between the subclavian vessels and the scalene muscles?
The subclavian vein travels in front of the anterior scalene muscle.
The subclavian artery travels behind the anterior scalene muscle.
485
Where does the brachial plexus and phrenic nerve run in relation to the scalene muscles?
Brachial plexus runs between the anterior and middle scalene muscle.
Phrenic nerve runs superficial to the anterior scalene muscle.
486
What is epiglottitis?
State the structures which it affects.
Inflammation and oedema of the epiglottis and supraepiglottic structures, affecting the:
- epiglottis.
- aryepiglottic folds.
- false vocal cord.
- true vocal cord.
487
What is the most likely causative pathogen of epiglottitis?
Haemophilus influenza B.
488
What is the most likely causative pathogen of croup?
Parainfluenza virus.
489
What head position will be seen on a patient with epiglottitis, and why?
Sniffing position - extension of the head.
Prevents the tongue from blocking the airway, and straightens the larynx, allowing more air to enter the lungs.
490
Which vessel does a pancoast tumour usually invade?
Right subclavian artery due to its close proximity to the apex of the lung.
491
What can occur due to an endotracheal tube being present for more than 2 weeks?
State what will need to be done because of this.
Fibrosis of the true vocal cords, meaning that they can be fixed in a paramedian position, which can cause severe breathing difficulties.
They will require a tracheostomy.
492
What is a pyramidal lobe?
Why do they develop?
A normal anatomical variant, present in 10-30% of the population, seen as a third lobe (usually superior to the isthmus) due to persistence of the thyroglossal duct, which develops as thyroid tissue.
493
Why does the thyroid gland move up on swallowing?
It is invested in the pre-tracheal fascia, which attaches to the hyoid bone, so when the hyoid bone is elevated by the suprahyoids, the thyroid is, too.
Thyroid is also attached to the cricoid via Berry’s (suspensory) ligament.
494
What is a thyroid ima?
State what it can arise from.
An additional artery supplying the isthmus of the thyroid in 7.5% of people, which runs in the midline, anterior to the trachea, to the isthmus.
It arises from the brachiocephalic trunk or arch of the aorta.
495
What do the thyroid veins drain into?
The superior and middle drain into the internal jugular vein.
The inferior thyroid vein drains into the left brachiocephalic trunk, after anastomosing.
496
What do the thyroid arteries arise from?
Superior thyroid artery from the external carotid artery.
Inferior thyroid artery from the thyrocervical trunk, which arises from the subclavian arteries.
497
Why do thyroglossal duct cysts move when swallowing and on tongue protrusion?
The thyroglossal duct has an attachment to the tongue, due to its development from the foramen caecum.
498
Where does the cervical plexus lie?
In the posterior triangle, on the surface of the scalenus medius and levator scapulae muscles, deep to the sternocleidomastoid.
Within the pre-vertebral layer of the cervical fascia.
499
Where do the sensory branches of the cervical plexus emerge from and what do they supply, generally?
Emerge from the middle of the posterior border of sternocleidomastoid.
Supply the skin of the neck, part of the scalp and ear, and the superior part of the thorax.
Contribute to dermatomes C2-C4.
500
What are the roots of the ansa cervicalis, what is it and what does it supply?
A loop of motor branches from C1 to C3.
It supplies the infrahyoid muscles.
501
What structure does the ansa cervicalis overly anteriorly?
The carotid sheath.
502
Where can the recurrent laryngeal nerve be found?
In Baehr’s triangle.
503
What are the borders of Baehr’s triangle?
Laterally - common carotid artery.
Medially - oesophagus/ trachea.
Superiorly - inferior thyroid artery.
504
What are the tumour subtypes of the lip/ oral cavity, the pharynx and larynx?
Lip/ oral cavity - tongue and floor of the mouth.
Pharynx:
- Oropharynx (including the tonsil).
- Nasopharynx.
- Laryngopharynx/ hypopharynx.
Larynx:
- Supraglottic.
- Glottis.
- Infraglottis.
505
What are the ages in which thyroid gland lumps are more likely to be malignant in?
Under the age of 20.
Over the age of 70.
506
What are some thyroid-specific risk factors for cancer?
Irradiation exposure - radioactive iodine and radiation leaks.
Family history and certain inherited conditions, such as FAP.
507
What are two pre-malignant states that increase the risk of head and neck cancers?
Leucoplakia - white patches on the tongue.
Erythroplakia - red patches on the tongue.
508
What are some specific risk factors for oral and oropharyngeal cancer?
Oral - betal nut chewing and dental hygiene.
Oropharyngeal - HPV.
509
What are the medical and surgical management of head and neck cancers, generally?
Medical:
- Radiotherapy.
- Chemotherapy, given to patients under the age of 70.
- Immunotherapy.
Surgical:
- Biopsy.
- Removal.
- Reconstruction.
510
What is the supportive management of head and neck cancers?
Help with:
- Swallowing.
- Feeding.
- Voice rehab.
- Pain.
- Supportive care.
511
What are the presentations, investigations and treatments of lip/ oral cancer?
Presentation;
- Lump, which can bleed or not.
- Pain, including referred pain to the ear (otalgia).
- Fixation of the tongue.
- Dysphagia and odynophagia.
Investigations:
- Biopsy.
- CT, MRI (including chest) and PET scan.
Treatment:
- Small tumour = excise and repair defect.
- Radiotherapy.
- Large tumours may need extensive surgery.
512
What are the presentations, investigations and treatments of pharyngeal cancer?
Presentation:
- Lump (nodal mets or primary).
- Pain, inc. otalgia.
- Dysphagia and odynophagia.
- Weight loss (often present late).
Investigations:
- CT and MRI (include chest), PET scan.
- Biopsy.
Treatment:
- Robotic or laser surgery for small tumours.
- Radiotherapy.
- Feeding assistance with gastrostomy tubes.
- Large tumours need extensive surgery.
513
What are the presentations of laryngeal cancer?
Dysphonia - voice change.
Dysphagia.
Referred otalgia.
Glogus - feeling of a lump in the neck.
Neck lump.
Weight loss.
Cachexia.
514
What are the investigations and treatment of the larynx?
Investigations:
- Imaging with CT and MRI (including chest).
- PET scan.
- Biopsy.
Treatment:
- Small tumours for resection, superficial with laser.
- Medium size do well with radiotherapy and chemotherapy.
- Larger tumours need extensive surgery.
515
What are some major surgeries associated with oral/ lip, pharyngeal or laryngeal cancer?
Oral/ lip - hemiglossectomy/ total glossectomy.
Pharyngeal - pharyngectomy or mandibular split.
Laryngeal - laryngectomy.
516
What is the difference between laryngectomy and tracheostomy?
Laryngectomy is where the swallowing and breathing mechanisms are disconnected through the removal of the larynx. A hole is then made into the trachea to help breathing.
Tracheostomy - a hole made into the trachea to help breathing, which can be temporary or permanent.
517
How does thyroid cancer usually first present?
Lump in the neck.
Compressive symptoms:
- Dysphagia.
- Feelings of strangulation.
Voice change.
Rarely have thyroid hormonal problems.
518
What is the investigations of thyroid cancer?
Triple assessment:
- History and examination.
- Imaging, ultrasound.
- Fine needle aspiration cytology, under ultrasound.
519
What are the 4 types of thyroid cancer?
State the extra one.
Papillary adenocarcinoma.
Follicular adenocarcinoma.
Medullary carcinoma.
Anaplastic carcinoma.
Lymphoma.
520
What are the treatment options for thyroid cancer?
Thyroidectomy - hemi or total.
Radioactive iodine.
Radiotherapy/ chemotherapy.
521
Which 3 cancers have a median survival of around 6 months?
Anaplastic carcinoma of the thyroid.
Mesothelioma.
Pancreatic cancer.
522
What are the potential consequences of thyroid surgery?
Bleeding.
Neck scar.
Laryngeal nerve damage.
Hypoparathyroidism - hypocalcaemia.
Hypothyroidism, given lifelong thyroxine.
Recurrence.
Thyroid storm - hyperthyroidism.
523
What are the nerves of the cervical plexus that run with the hypoglossal nerve?
State their roots and functions.
Nerve to geniohyoid - C1 - moves the hyoid bone anteriorly and upwards, expanding the airway.
Nerve to thyrohyoid - C1 - depresses the hyoid bone and elevates the larynx.
524
What muscles, supplied by larger nerves, receive branches from the cervical plexus?
C2-C3 - pre-vertebral muscles and sternocleidomastoid.
C3-C4 - levator scapulae, trapezius and scalenus medius.
Middle and anterior scalenes, too.
525
What are the roots of the greater auricular nerve and what does it innervate?
State what it communicated with.
C2 and C3.
Supplies the sensation to the external ear and skin over the parotid gland.
Communicates with the auricular branch of the vagus nerve and posterior auricular branch of the facial nerve.
526
What are the roots of the transverse cervical nerve and what does it innervate?
C2 and C3.
Supplies sensation to the anterior neck, anterolateral skin of the neck and upper sternum.
527
What are the roots of the lesser occipital nerve and what does it innervate?
What does it communicate with?
C2 (with some C3 from some people).
Supplies the posterosuperior scalp.
It communicated with the posterior branch of the greater auricular nerve.
528
What are the roots of the supraclavicular nerve and what does it innervate?
C3 and C4.
Supplies the skin overlying the supraclavicular fossa and upper thoracic region. Also supplies the sternoclavicular joint.
529
At what point in gestation does the thyroglossal duct normal regress?
10th week.
530
What does a thyroglossal cyst result from and what can occur if they are not treated?
State how they are treated.
Results from a build-up of secretions within the duct, presenting as a midline lump.
If untreated, the lump can become infected and form a cutaneous fistula.
Thyroglossal cysts and fistulae are treated with surgical excision.
531
What are the superior and inferior parathyroid glands derived from?
Superior - fourth pharyngeal pouch.
Inferior - third pharyngeal pouch.
532
What is the arterial supply and venous drainage to the parathyroid glands?
Arterial supply is from the inferior thyroid arteries.
Collateral arterial supply is from the superior thyroid and thyroid ima arteries.
Venous drainage is from the superior, middle and inferior thyroid veins.
533
What is the lymphatic drainage of the parathyroid glands?
Paratracheal and deep cervical lymph nodes.
534
What is the nervous supply to the parathyroid glands?
Sympathetic nerves derived from thyroid branches of the cervical ganglia.
535
What are the clinical features of hypocalcaemia?
Tetany.
Muscle cramps.
Paraesthesia of the fingers, toes and mouth.
536
What head and neck cancers do EBV and sunlight increase the risk of developing?
EBV for nasopharyngeal.
Increased sunlight exposure is lip cancer.
537
Which sex do thyroid cancers present in more, and why?
Women, due to hormonal differences.
538
Why use radiographs for the head and neck?
Minor skull trauma.
Cervical spine trauma.
Foreign bodies within the head and neck.
Looking for potential facial fractures.
539
Why use ultrasound for the head and neck?
Thyroid evaluation and fine needle aspiration.
Superficial head and neck masses, particularly of the parotid and submandibular glands.
Superficial infection.
Lymphadenopathy.
Carotid Doppler to evaluate the risk of strokes.
540
Why use CTs for the head and neck?
Urgent trauma cases.
Acute focal neurological symptoms - impairments of cranial nerve, spinal cord or brain function, e.g. seizures, facial weakness, etc.
Malignancy - can stage, such as neck tumours with spread to the nodes.
Infection - retropharyngeal abscess.
Angiographic imaging of the arteries and veins.
541
Why use MRI for the head and neck?
Tumour evaluation.
Epilepsy.
Cervical spinal cord traumatic injury.
Head and neck tumours.
542
What pathologies can be seen on a skull radiograph?
Skull fractures.
Suture lines.
Pneumocranium - air within the cranial cavity.
Fluid level.
Lytic soft tissue - erosion of the bone (mets/ myeloma).
543
What is pointed to in this X-ray?
Yellow - coronal sutures.
Red - lamdoid sutures.
Blue - middle meningeal artery impression on the skull.
544
What is seen on this X-ray?
Sagittal suture.
545
What abnormality is seen on this X-ray?
Fracture of the maxilla is not seen but may be there as could be blood pooling in the maxillary sinus.
Could be acute sinusitis.
546
What abnormality is seen on this X-ray?
State the tissue which is most likely to be compromised.
Inferior rectus muscle most likely to be involved.
547
What abnormality is seen in this X-ray?
Black eyebrow sign, signifying gas in the orbit.
548
What abnormalities can be seen on this MRI?
Basal skull fractures.
549
Why would cervical spine radiographs be performed?
Fractures/ subluxations.
Atlanto-axial subluxation.
Facet dislocation.
Vertebral erosion.
Soft tissue widening.
Lung lesions/ pneumothorax.
550
What abnormality is seen on this X-ray?
Jefferson fracture - burst fracture of the atlas.
551
What is seen in this X-ray?
Spondylolisthesis - C6 vertebra fracture-dislocation of the pars interarticularis.
552
Label the required lobes and ventricles of the brain MRI.
553
Label the required lobes and ventricles of this MRI.
554
How do you treat an extradural, subdural haemorrhage and subarachnoid?
Extradural - neurosurgical emergency.
Subdural - correction of anticoagulation (warfarin) if small, neurosurgical emergency is large or symptomatic.
Subarachnoid - trauma is smaller, so usually correction of anticoagulation; aneurysms are much larger so usually neurosurgical.
