Head & Neck Flashcards
(289 cards)
1
Q
Describe 3 structural differences between cervical vertebrae and others
A
Triangular vertebral foramen
Bifid spinous process
Transverse foramina within the transverse processes
2
Q
What passes through the transverse foramina?
A
The vertebral artery, vein and sympathetic nerves
3
Q
How does C7 differ to other cervical vertebrae?
A
The vertebral artery runs around the vertebral body rather than through the transverse foramina.
The spinal nerves appear above AND below C7 - which is why C8 is present when there are only 7 cervical vertebrae.
4
Q
At which level do the vertebral arteries enter the transverse foramina?
A
C6
5
Q
Describe the relationship of the vertebral arteries to C1 (atlas)
A
The vertebral artery runs around along the groove for the vertebral artery rather than through transverse foramen.
6
Q
State the joints at which rotation and flexion of the head occur
A
Rotation - atlanto-axis joint
Flexion - atlanto-occipital joint
7
Q
Name the muscle which causes rotation of the head & it’s innervation
A
The sternocleidomastoid. Innervated by the spinal accessory nerve (CNXI)
8
Q
Explain why vertebral subluxation at C2/3 is more dangerous than at C6/7
A
Vertebral subluxation at C2 involves the anterior displacement of C2 with respect to C3. This is likely to have spinal cord involvement with a risk of quadraplegia or death
9
Q
Describe the pattern of trauma associated with hangman’s fracture.
How is this different to a Jefferson #?
A
Hangman’s fracture is due to the hyperextension of the head on the neck which leads to fracture of the pars interarticularis of the axis - the result of which is shearing or compression of the spinal cord.
Jefferson fracture, or burst fracture is also known as the “burst #” and could be due to a head first fall from height. The axis breaks into several segments although this is less dangerous due to the wide vertebral foramen.
10
Q
Explain why CNXI (Spinal Accessory Nerve) can be tested by asking the patient to shrug their shoulders
A
The descending fibres of the trapezius muscle are supplied by CNXI. The action of these fibres is to elevate the spine of the scapula and clavicle leading to shrugging of the shoulders.
11
Q
Describe the actions of the sternocleidomastoid
A
Rotation and lateral flexion of the head
12
Q
Name the 4 suprahyoid muscles and state their action
A
digastric, mylohyoid, stylohyoid, geniohyoid
These elevate the hyoid and larynx during swallowing
13
Q
Name the 4 infrahyoid muscles and state their action
A
Omohyoid, thyrohyoid, sternohyoid and sternothyroid.
14
Q
How does the nerve supply to the anterior and posterior bellies of the digastric muscle differ?
A
Anterior belly = inferior alveolar nerve from the mandibular branch of trigeminal.
Posterior belly = digastric branch of the facial nerve
15
Q
Name the muscle responsible for, and the branch of the facial nerve responsible for their innervation:
a) Elevating eyebrows
b) Smiling
c) Keeping cheeks taut
d) Closing the eyelids
A
a) Frontalis- temporal branch
b) Levator anguli oris
c) Buccinator muscle - buccal
d) Orbicularis oculi - zygomatic
16
Q
Explain why damage to the facial nerve causes ptosis
A
Ptosis is the drooping of the eyelid. This is because of loss of innervation to the muscles that elevate the brow which gives an overall drooped appearance to the eyelid
17
Q
Explain why yawning can lead to dislocation of the TMJ
A
Can over-open the jaw causing the mandible to displace anteriorly from the mandibular fossa
18
Q
Name the 4 muscles of mastication and what is their innervation?
A
Masseter, temporalis, medial and lateral pterygoids.
These are innervated by the mandibular branch of the trigeminal nerve (V3)
19
Q
Describe the structure of the bones of the cranium
A
The bones are flat bones which form fibrocartilaginous joints, or sutures with one another.
20
Q
Name the bones which articular at each of the following lines:
a) Lamboid
b) Coronal
c) Sagittal
A
a) Occipital and parietal
b) Frontal and parietal
c) Parietal bones
21
Q
Explain why damage to the pterion can lead to an extradural haematoma and why is this dangerous?
A
The middle meningeal artery runs underneath the pterion which can be ruptured if this structure is damaged. This is dangerous because of increased intracranial pressure.
22
Q
Explain why damage to the ethmoid bone can lead to anosmia?
A
The ethmoid bone allows passage for the olfactory nerve fibres through the cribriform plate. If this is damaged then the olfactory cells can be damaged resulting in a loss of smell.
23
Q
Describe the structure of the mandible
A
The mandible is a symmetrical horseshoe shaped, irregular bone that forms the jaw. It also articulates with the temporal bone at the TMJ joint.
24
Q
Describe how the structure of the skull differs in the neonate. Why is this important? Therefore why is premature birth a risk?
A
- Cranial sutures are wide, bones are held together by thick connective tissue
- Lambda and bregma do not exist (more a membranous islands)
The open sutures allow for the bones to be pushed together during birth, with the serrated bone edges temporarily interlocking to protect the brain.
If birth is premature then the bones do not interlock which means a high probability of brain damage.
25
State 4 roles of the fascia in the head and neck
- Compartmental
- Aid in movement of structures
- Form natural planes
- Determine the spread of infection
26
Explain why infection in the retropharyngeal space can lead to a unilateral abscess?
How far can an infection spread?
This is a potential space, posterior to the oesophageal wall and anterior to the pre-vertebal fascia. Infection can come from the nasopharynx, paranasal sinuses and middle ear.
This could spread to the diaphragm
27
State how far an infection can spread along the parapharyngeal space.
Describe a complication of infection within this space.
Up to the level of the mediastinum (T2/3).
Could affect the carotid sheath structures causing internal jugular vein thrombosis or
28
Describe the borders and contents of the carotid triangle
Superior: posterior belly of digastric
Lateral: medial border of SCM
Inferior: Superior belly of omohyoid
Contents = common carotid artery, internal jugular vein, hypoglossal and vagus nerve
29
Describe the borders and contents of the posterior triangle
Anterior: posterior border of SCM
Posterior: anterior border of trapezius
Inferior: middle 1/3 of clavicle
Contents: muscles, vasculature: EXTERNAL JUGULAR VEIN, CNXI
30
Name the triangle formed by the anterior and posterior bellies of digastric and the mandible.
Submandibular triangle
31
What is the clinical significance of the carotid triangle?
Area of the carotid sinus - presence of baroreceptors (in. CNIX)
32
Explain why subdural haematomas have the potential to be life-threatening
Subdural haematomas increase the intracranial pressure which could cause compression on the brain. The brainstem may prolapse through the foramen magnum due to the increased pressure, compressing the breathing centres leading to death.
33
Describe the location at which the facial artery can be palpated
Can be palpated on the mandible just anterior to the masseter muscle.
34
What condition causes paralysis of SCM and how can childbirth be can cause?
Spinal accessory nerve palsy or torticollis. Childbirth may cause trauma to this nerve or the muscle directly due to hyperextension or tightening of the muscle during delivery.
35
Why is a runny nose is a symptom of a fracture of the ethmoid bone?
Damage to the cribriform plate of the ethmoid bone which leads to a route for cerbrospinal fluid to leak.
36
Why can a fracture of the mandible lead to numbness in the lower teeth and the central part of the lower lip?
The inferior alveolar nerve which supplies the lower teeth and the later mental nerve which supplies the lower lip may both be affected by injury to the mandible because they lie along the mandible and could be compressed.
37
At the start of week 4, what proportion of the embryo does the H+N occupy?
Folding has completed - H&N = about half of the length
38
Describe how the neural tube is formed
The notochord signals ectoderm thickening which causes the edges to elevate out of the plane of the disk, curling towards each-other to create the neural tube.
39
Describe the basic components of the pharyngeal arches
Each pharyngeal arch is a system of mesenchymal proliferations in the neck region of the embryo which develops into muscles, cartilages, nerves and arteries.
40
Describe the structures which are contributed to by the first arch
Nerve: trigeminal nerve (CNV)
Muscles: muscles of mastication, digastric & mylohyoid
Arteries: internal carotid artery
Cartilages: meckel's cartilage (becomes the mandible, malleus & incus)
41
How can the neural tube be segmented?
Anterior end can be split into 3 vesicles:
Prosencephalon - forebrain
Mesencephalon - midbrain
Rhombencephalon - hindbrain
42
Why are the muscles of facial expression innervated by CNVII?
Both are derivatives of pharyngeal arch 2.
43
Suggest why the nerve to stapedius originates from the second arch
Nerve to stapedius is a branch of the facial nerve (branches within the facial canal) which is the 2nd arch derivative
44
Describe the innervation of the tongue
Motor - hypoglossal (CNXII)
Sensory (general) - Glossopharyngeal (CNIX)
(special) Anterior 2/3 = chorda tympani (CNVII)
Posterior 1/3 = glossopharyngeal (CNIX)
45
Describe the remnants of the cartilage of the 3rd arch
Greater cornu (horn) of hyoid, Inferior body of hyoid bone
46
How does the mandible form?
Derived from Meckel's cartilage of the 1st arch. Undergoes membranous ossification.
47
Describe how the nerves given off by the 4th and 6th arches differ
Both arches nerves are from the Vagus nerve (CNX) however the 4th arch associates with the Superior laryngeal nerve
6th arch associates with the recurrent laryngeal nerve.
48
State the pharyngeal arch from which the thyroid cartilage arises
4th & 6th Pharyngeal arches
49
What is the primative aortic arch associated with:
a) Internal carotid
b) Aortic arch
c) Brachiocephalic trunk
d) pulmonary arch
a) 3rd
b) Left 4th
c) Right 4th
d) 6th
50
What is the clinical importance of the recurrent laryngeal nerve, with relation to the aortic arch?
The RLN loops under the 4th arch artery during development passing under the ductus arteriosus.
This is a site of possible compression and damage to the RLN.
51
On the whole, what do the pharyngeal pouches become?
The pharyngeal gut tube and it's glandular derivatives
52
Describe the development of the palatine tonsils
2nd Pharyngeal Pouch
Epithelial proliferation followed by colonisation of lymphoid precursors
53
Describe the development of the parathyroid glands and the thymus
The thymus is derived from the ventral component of the 3rd Ph. Pouch, developing as two seperate lobes that migrate inferiorly, merging to form a bilobular gland.
Parathyroid is derived from the dorsal component of the 3rd and 4th Ph. Pouches - superior and inferior respectively.
54
Describe the embryological origin of the external auditory meatus and middle ear.
1st Pharyngeal Pouch
Space between the cartilaginous bars of the 1st and 2nd arch which later become the ossicles.
55
What is a fisulae and why may babies be born with fistula or cysts along the anterior border of the SCM?
Fistula = abnormal opening between 2 epithelial lined tracts
Failure of the pharyngeal clefts to obliterate following 2nd arch growth.
56
List 3 functions of the lymphatic system
1. Returning lymph back to the blood circulation
2. Immune function - contains macrophages
3. Transport of FA via chylomicrons
57
Why do patients who are immobile suffer from lymphoedema?
Lymph vessels are valveless with no pump present - drainage relies on external muscle contraction to move the lymph against gravity. (Passive constriction)
58
Describe the composition of lymph
- Porous
- Tissue fluid
- Protein
- Microbes
- Chylomicrons
59
Describe the route of lymph from capillaries to the vasculature
```
Tissue fluid
Lymphatic capillaries
Lymphatic afferent vessels
Lymph nodes
Lymphatic efferent vessels
Lymphatic trunks
Lymphatic ducts
```
60
Why is the course of lymph vessels different between the body and the H&N region?
H&N lymphatic drainage is bilateral with an equal amount draining into the left lymphatic duct and the right lymphatic duct.
However the body does not have an equal distribution of drainage and the majority drains into the left lymphatic duct.
61
How can the lymphatics of the H&N be classified?
Superficial (regional) or deep (terminal)
62
What structures comprise waldeyer's ring?
Adenoids
Lingual Tonsils
Palatine tonsils
63
Why may infection of the tonsils cause small, firm swellings at the angle of the jaw?
Drainage of the tonsils is into the jugulo-digastric terminal lymph node which is positioned inferior to the angle of the mandible.
64
Name the lymph node which becomes inflammed in tonsilitis
Pharyngeal tonsil/adenoids
65
Describe the arrangement of the deep nodes of the neck
Deep to the sternocleidomastoid and in close relation to the internal jugular vein and carotid sheath are the jugulodigastric and jugulo-omohyoid
*note the supraclavicular lymph nodes should also be palpated on examination
66
Why does GI cancer lead to swelling of the left supraclavicular lymph node?
If cancer cells enter the lymphatic system from the GI system then they would drain into the supraclavicular lymph node as their primary mode of metastases.
67
Suggest a diagnosis for an enlarged right supraclavicular lymph node
- Lung infection
- Oesophageal cancer
(Drains the lungs, oesophagus & mid section of chest)
68
State the vertebral level at which the carotid artery bifurcates
C4
69
Explain why massaging this area can help manage a tachycardia
Stimulation of baroreceptors which increases vagal parasympathetic stimulation to the SAN to slow the rate of depolarisation and therefore slowing the heart rate (brachycardia)
70
Name 3 main branches of the subclavian artery
- Thyrocervical trunk
- Internal thoracic artery
- Vertebral artery
71
Describe the structure of the thyrocervical trunk
Branches to give ascending and transverse cervical; subscapular and the inferior thyroid artery
72
Describe the course of the vertebral artery
Ascends through the transverse foramen of cervical vertebrae (C6-C1)
*C1 the course is along the vertebral artery groove not through the transverse foramina
73
Explain why carotid artery bifurcation is a common site of atherosclerosis
It is an area of increased turbulance which increases the risk of endothelial cell injury. Endothelial cell injury allows for LDL uptake and deposition. This leads to inflammation and lumen narrowing.
74
Describe how atherosclerosis can lead to a stroke
More likely to lead to an ischaemic stroke.
Occlusion of a cerebral artery due to severe atherosclerosis or rupture of an atherosclerotic plaque which leads to thrombus formation and acute lumen narrowing. This results in reduced oxygen supply to an area of the brain leading to a stroke.
75
Name the branches of the external carotid artery
```
Superior thyroid artery
Ascending pharyngeal
Lingual
Facial
Occipital
Posterior auricular artery
Superficial Temporal artery
Maxillary
```
*latter 2 are terminal arteries
76
Name the branch of the maxillary artery that runs under the pterion
Middle meningeal artery
77
Name the two arteries of the scalp which come from the internal carotid
Supra-orbital & supratrochear
78
Explain why lacerations of the scalp lead to profuse bleeding
The blood supply to the scalp lies within the dense connective tissue layer just underneath the skin.
The blood supply is a vast anastamosis network which means bleeding can be severe.
79
Why may bursting a spot by the nose cause cavernous sinus thrombosis?
Danger triangle of the face is formed from the medial angle of the eyes to the corners of the mouth.
The drainage from this area is via the supratrocheal and supraorbital veins which form the angular (and then the facial) vein. The facial vein drains into the cavernous sinus.
As the veins of the face are valveless there is a risk of infection tracking back into the cavernous sinus. This would cause an immune response and blockage due to thrombosis.
80
Why may cavernous sinus thrombosis cause abnormalities in the motor functions of the eye?
The cavernous sinus has close relations to several nerves which supply the muscles of the eye*:
- CNIII (occulomotor)
- CNIV (trochlear)
- CNVI (abducens)
Thrombosis could damage these nerves which would result in loss of stimulation to the rectus and oblique muscles of the eye.
* + V1/V2
81
How may infection spread from the scalp to the meninges?
Drainage of the scalp is via the emissary and diploid veins which drain into the dural venous sinuses.
As these veins are valveless, infection could spread into these sinuses which lie between the periosteal and meningeal dura within the cranial cavity. This poses a risk to the meninges.
82
Describe the course of the thoracic plane (plane of ludwig) and name 3 events/structures which lie here.
Divides the mediastinum into superior and inferior sections. Horizontally runs from angle of louis to T4
- Pulmonary trunk
- Arch of the aorta
- The carina
- Ligamentum arteriosum
83
What is the origin of neural crest cells?
Specialised population of cells from the lateral neuroectoderm.
Known as a "fourth germ lineage".
84
What are the structures that arise from the maxillary prominences?
Cheeks, lateral upper lip, jaw, secondary palate.
85
What is the stomadodeum?
Depression within the FNP which is the position of the buccopharyngeal membrane.
86
What external features are derived from the frontonasal prominence?
Forehead, nose (+bridge of the nose), philtrum, front 4 teeth, primary palate.
87
Describe the formation of the nose
Nasal placodes form within the FNP.
Medial and lateral nasal prominences form around the nasal placode.
As the maxillary prominences of the 1st ph. arch begins to grow medially they push the nasal prominences along with them.
Medial nasal prominences fuse in the midline and with the maxillary prominences.
88
Explain how abnormalities in the development of the nose can lead to a cleft lip
Results from failure of either the primary or secondary palatal shelves to reach the midline or fuse in the midline.
89
Describe how the nasal and oral cavities become seperated
Maxillary prominences form palatal shelves.
Due to the slow development of the mandible these originally grow downwards
Once the mandible has formed the palatal shelves can grow towards each other where they fuse in the midline.
90
Explain the origin of a dual cleft lip and palate
This is where the maxillary prominence has failed to fuse with the medial nasal prominence and failed to fuse with the other maxillary prominence
91
How to the eyes develop?
Optic vesicle arises in the forebrain
Grows out towards the lens placode which invaginates and pinches off.
The optic vesicle gives rise to the lens and the retina is formed from diencephalon (forebrain)
92
How does the position of the eye change during development?
Originates from the sides of the head but moves anterio-medially as the facial prominences migrate.
93
Name the structures of the ear that arise from the 1st pharyngeal pouch
Eustachian tube, tympanic membrane.
94
Name the auricles which come from the 1st and 2nd pharngeal arches respectively
1st - Malleus & incus
| 2nd - Stapes
95
What is the fate of the otic placode
These invaginate to form auditory vesciles which form the membranous labyrinth of the inner ear (cochlea and semi-lunar canals)
96
Explain why exophthalmos occurs in hyperthyroidism
Exopthalmos = abnormal protrusion of the eyeball or eyeballs.
In hyperthyroidism this is due to inflammation of the fatty tissues and muscles behind the eyeball.
97
Explain why nasal secretions increase when people cry
Tears arise from the lacrimal gland which drains into the medial corner of the eye by lacrimal ducts.
Tears then drain into the nasolacrimal duct which drains into the inferior nasal meatus
98
State the part of the nose into which the nasolacrimal duct drains
Inferior meatus
99
Name two structures which pass through the optic canal
```
Opthalmic artery
Optic nerve (CNII)
```
100
Explain why raised ICP can cause papilloedema
Venous drainage from the eye is compromised leading to distension of the retinal veins which causes papilloedema
101
State the contents of the superior orbital fissure
```
CNIII (Superior and inferior branches)
CNIV
CNVI
Branches of CNV1
Superior opthalmic vein
```
102
Why does damage to the optic chiasm only affect lateral vision
The retina is essentally split into two halves with a slightly different nervous supply on the "temporal" half to the "nasal" half.
The nerves running through the optic chiasm supply the nasal retina, but the temporal retina innervation runs lateral to the chiasm so wouldn't be affected if it was damaged..
103
State a cause of damage to the optic chiasm
Pituitary adenoma
104
Which part of the orbit is most likely to be fractured in a blow to the skull and why?
Medial wall. This is because it is made of several small, thin bones.
105
Why may a blow out fracture of the orbit lead to infection of the cavernous sinus?
FIND THIS OUT
106
Describe two complications of blowout fractures of the orbit?
Trapped inferior rectus muscle
| Double vision
107
Why does damage to CNV1 increase the risk of infection to the eye?
CNV1 supplies the sensory innervation to the cornea. Damage to this nerve means loss of the corneal reflex. This means that dust, bacteria etc may get trapped leading to increased risk of infection
108
Describe the arterial supply to the eye
Opthalmic artery travels through the optic canal alongside CNII. This is a branch of the internal carotid artery and gives rise to the central retinal artery.
109
Why may a nasal furuncle cause cavernous sinus thrombosis?
Venous drainage of the nose is via the facial vein which drains into the cavernous sinus. The valveless nature of these veins increases the risk of spread of infection from the nose.
110
Describe the complications of cavernous sinus thrombosis
CNIII, CNIV, V1 & V2 and CNVI all travel lateral to the cavernous sinus. Thrombosis may damage these nerves leading to:
- Loss of motor movement of the eye
- Loss of sensation to the cornea
- Loss of sensation to the opthalmic and maxillary areas of the face
The internal carotid artery may also be affected. This could lead to loss of blood supply to neural structures and the eye
111
A patient suffers damage to CNVII. Give 2 reasons why they are more likely to suffer from eye infections
Parasympathetic supply to the lacrimal gland is prevented which leads to reduced lacrimal gland secretions so eye dries out.
Reduced motor innervation to the orbicularis oculi therefore the eye doesn't close fully - loss of protective blink reflex.
112
State 3 infectious causes of conjunctivitis
Staphylococcus aureus
Streptococcus pneumoniae
Haemophillus influenzae
113
A patient presents with an inability to blink. Give 3 potential causes of this
Facial nerve paralysis
Occulomotor nerve palsy - levator palpebrae superioris paralysed
Skin disorders such as Ichythyosis
114
Outline 3 causes of CNIII dysfunction.
Cavernous sinus thrombosis
Head injury
Brainstem injury
115
How may CNIII palsy present?
Double vision (loss of occulomotor function)
Ptosis (unopposed orbicularis oculi)
Mydriasis (unopposed dilator papillae)
116
Why do patients with horner's syndrome suffer from hemifacial anhydrosis?
Loss of sympathetic nerve supply to the sweat glands to the side of the face where the lesion has occurred.
117
Why do patient's with harlequin syndrome suffer from excessive sweating on the unaffected side and flushing on the affected side?
Harlequin syndrome is a sympathetic nervous system problem where there has been an ipsilateral lesion to the sympathetic neurones that usually cause vasodilation.
Patients with these lesions will have dysfunctional thermoregulation and therefore may have excessive sweating on the unaffected side to compensate for the lack of sweat production on the affected side. In some patients there is a lack of flushing on the affected side also.
118
Explain the difference between a stye and a meiobian cyst
Stye = tarsal gland inflammation
| Meiobian cyst = ciliary (or meiobian) gland infection
119
Describe the pathophysiology of a detacted retina
Retina and choriod develop from different tissues which mean there is a potential space between them. Head injury can cause secretions into this potential space which pushes away the two layers
120
Explain why a central artery embolism causes severe visual loss
The central artery is a terminal artery and therefore the only blood supply to the retina. If an embolism occurs there is no blood supply to the retina and therefore sight is lost.
121
Why can infection of the pterygoid venous plexus cause cavernous sinus thrombosis?
The pterygoid venous plexus drains into the cavernous sinus therefore as the plexuses are valveless, infection can spread.
122
State 3 functions of the nose
Olfaction
Respiration (humidification & warming of air)
Immune (filters large particles)
123
Outline the following features of the external nose:
a) bones
b) cartilages
a) Nasal bone; nasal process of maxillary bone; frontal bone
| b) minor and major alar cartilages; septal cartilage; lateral cartilage
124
Describe the boundaries of the nasal cavity
Anterior - nares
Medial - nasal septum & conchae
Lateral - nasal mucosa & skin
Posterior - choanae & nasopharynx
125
How does the histology of the nasal mucosa contribute towards the runny nose associated with infections
Epithelium = pseudostratified, ciliated mucosa.
Cilia trap bacteria to contribute to the nasal secretions.
Mucosa is continuous with the paranasal sinuses which may gather infection.
Glands within the mucosa increase rate of secretion
126
Where is the sphenoethmoidal recess?
Above the superior turbinate
127
What drains into the sphenoethmoidal recess?
Sphenoid sinus
128
Why may infection of the sphenoid sinus spread to the maxillary sinus?
Sphenoid sinus drains into the sphenoethmoidal recess which is superior to the hiatus semilunaris that the maxillary sinus drains into.
Infection can therefore drain directly into the maxillary sinus as it lies inferior to its duct.
129
Explain why maxillary sinusitis is the most common sinusitis
Drainage of the maxillary sinus is superior to it's position therefore pathogens can easily enter the sinus due to the simple effect of gravity
130
Name the locations for which the following sinuses drain:
a) frontal
b) maxillary
c) ethmoid
d) sphenoid
```
A-C = middle meatus via semilunaris hiatus (although ethmoid can be broken into 3 sections which have slightly different drainage sites)
D = sphenoethmoidal recess
```
(Anterior ethmoid - hiatus semilunaris; middle ethmoid - ethmoid bulla; posterior ethmoid - superior meatus)
131
Name the structure through which the olfactory nerve passes
Cribriform plate (ethmoid bone)
132
Other than anosmia, name and explain another sign of damage to the Cribriform plate of ethmoid
Rhinorrhoea* - this is due to leakage of cerebral spinal fluid due to damage to the ethmoid sinus which has relations to the anterior cranial fossa.
* general term for nasal secretions. If clear it is likely to be CSF. Red = blood
133
Describe the blood supply to the nose, naming the area of anastomoses
Area of anastomoses = littles area/keisselbachs area
Facial artery
Maxillary artery - sphenopalatine and greater palatine branches
Ophthalmic artery - anterior and posterior ethmoid branches
134
Explain why nosebleeds can be life threatening
Large blood supply - 3 major arteries supply the area and anastomose at littles area.
Posterior bleeds are more worrying as they are from the sphenopalatine artery which is larger and in a more difficult area to stop.
135
Describe the venous drainage of the nose
Ophthalmic -> facial vein -> cavernous sinus
| Pterygoid plexus
136
Explain why infection of the nose may spread to the cavernous sinus
Infection can drain into the cavernous sinus via the facial veins. The veins in this area (particularly the danger triangle) are valveless which means that infection can spread.
137
What is the potential consequences of infections spreading to the cavernous sinus?
Cavernous sinus thrombosis
Meningitis
Brain abscess
138
Describe the innervation of the nose
Special sensory - ophthalmic nerve (CNI)
General sensory - ophthalmic and maxillary branches of trigeminal (V1/2)
Motor - muscles of facial expression supplied by the facial nerve (CNVII)
139
State the innervation of each of the 4 sinuses
Frontal - supraorbital and supratrochlear branches of V1
Maxillary - infraorbital nerve & greater palatine branches of V2
Ethmoid - branches of CNI
Sphenoid - V1/2
140
Where may infection spread if the sphenoid sinus is infected
Middle cranial fossa superiorly or the poster cranial fossa & the pons posteriorly
141
Why may a deformed nasal septum predispose to sinusitis?
Blockage of the sinus ducts leading to stasis of secretions within the sinus. This can lead to irritation/infection and inflammation of the sinuses (sinusitis)
142
How can a deformed nasal septum be managed?
Rhinoplasty/submucosal resection
143
Describe the route by which infection may spread from the nose to the conjunctiva
Infection within the nasal cavity tracking up through the ethmoid air cells (within the ethmoid sinus) to enter the orbit and infect the conjunctiva.
Another possible route is via the venous drainage. As the veins of the face are valveless infection could spread via the ophthalmic vein which drains the nose and the orbit.
144
Why may infection of the ethmoid sinus affect a patient's vision?
Air cells are in close proximity to the optic nerve therefore if infection spreads through the ethmoid sinus it may damage the nerve
145
Why is it important to drain a septal haematoma?
Septum is made up of cartilage which is an avascular structure and is supplied by the periosteal layer. When a haematoma forms this layer is separated from the cartilage which means it is at risk of avascular necrosis. Therefore drainage followed by compression is important.
Furthermore, if a haematoma forms and then collapses there is a risk of nasal obstruction which could compromise the airways.
146
Why may dental work lead to maxillary sinusitis
Maxillary sinus is connected to the oral cavity via the front two molars. If damage to this plate occurs then a fistula may form which provides a route for bacteria to spread from the oral cavity.
147
What is a dangerous complication of infection spreading from dental work?
Sepsis
148
Name 5 risk factors for epistaxis
```
Trauma
Weakened septum
Mucosal drying
Medication side effects
Thinning of the nasal cavity
```
149
Describe the management ladder for epistaxis
1. Pinch cartilaginous part of the nose with thumb and index finger
2. Anterior packing
3. Posterior nasal packing
4. Surgical intervention - e.g. Ligation of sphenopalatine artery
150
Why does sinusitis cause headaches?
Inflammation causes swelling and congestion, including the blockage of drainage of the sinus. This leads to an increase in pressure which causes the headache symptoms.
151
State 3 functions of the nose
Olfaction
Respiration (humidification & warming of air)
Immune (filters large particles)
152
Outline the following features of the external nose:
a) bones
b) cartilages
a) Nasal bone; nasal process of maxillary bone; frontal bone
| b) minor and major alar cartilages; septal cartilage; lateral cartilage
153
Describe the boundaries of the nasal cavity
Anterior - nares
Medial - nasal septum & conchae
Lateral - nasal mucosa & skin
Posterior - choanae & nasopharynx
154
How does the histology of the nasal mucosa contribute towards the runny nose associated with infections
Epithelium = pseudostratified, ciliated mucosa.
Cilia trap bacteria to contribute to the nasal secretions.
Mucosa is continuous with the paranasal sinuses which may gather infection.
Glands within the mucosa increase rate of secretion
155
Where is the sphenoethmoidal recess?
Above the superior turbinate
156
What drains into the sphenoethmoidal recess?
Sphenoid sinus
157
Why may infection of the sphenoid sinus spread to the maxillary sinus?
Sphenoid sinus drains into the sphenoethmoidal recess which is superior to the hiatus semilunaris that the maxillary sinus drains into.
Infection can therefore drain directly into the maxillary sinus as it lies inferior to its duct.
158
Explain why maxillary sinusitis is the most common sinusitis
Drainage of the maxillary sinus is superior to it's position therefore pathogens can easily enter the sinus due to the simple effect of gravity
159
Name the locations for which the following sinuses drain:
a) frontal
b) maxillary
c) ethmoid
d) sphenoid
```
A-C = middle meatus via semilunaris hiatus (although ethmoid can be broken into 3 sections which have slightly different drainage sites)
D = sphenoethmoidal recess
```
(Anterior ethmoid - hiatus semilunaris; middle ethmoid - ethmoid bulla; posterior ethmoid - superior meatus)
160
Name the structure through which the olfactory nerve passes
Cribriform plate (ethmoid bone)
161
Other than anosmia, name and explain another sign of damage to the Cribriform plate of ethmoid
Rhinorrhoea* - this is due to leakage of cerebral spinal fluid due to damage to the ethmoid sinus which has relations to the anterior cranial fossa.
* general term for nasal secretions. If clear it is likely to be CSF. Red = blood
162
Describe the blood supply to the nose, naming the area of anastomoses
Area of anastomoses = littles area/keisselbachs area
Facial artery
Maxillary artery - sphenopalatine and greater palatine branches
Ophthalmic artery - anterior and posterior ethmoid branches
163
Explain why nosebleeds can be life threatening
Large blood supply - 3 major arteries supply the area and anastomose at littles area.
Posterior bleeds are more worrying as they are from the sphenopalatine artery which is larger and in a more difficult area to stop.
164
Describe the venous drainage of the nose
Ophthalmic -> facial vein -> cavernous sinus
| Pterygoid plexus
165
Explain why infection of the nose may spread to the cavernous sinus
Infection can drain into the cavernous sinus via the facial veins. The veins in this area (particularly the danger triangle) are valveless which means that infection can spread.
166
What is the potential consequences of infections spreading to the cavernous sinus?
Cavernous sinus thrombosis
Meningitis
Brain abscess
167
Describe the innervation of the nose
Special sensory - ophthalmic nerve (CNI)
General sensory - ophthalmic and maxillary branches of trigeminal (V1/2)
Motor - muscles of facial expression supplied by the facial nerve (CNVII)
168
State the innervation of each of the 4 sinuses
Frontal - supraorbital and supratrochlear branches of V1
Maxillary - infraorbital nerve & greater palatine branches of V2
Ethmoid - branches of CNI
Sphenoid - V1/2
169
Where may infection spread if the sphenoid sinus is infected
Middle cranial fossa superiorly or the poster cranial fossa & the pons posteriorly
170
Why may a deformed nasal septum predispose to sinusitis?
Blockage of the sinus ducts leading to stasis of secretions within the sinus. This can lead to irritation/infection and inflammation of the sinuses (sinusitis)
171
How can a deformed nasal septum be managed?
Rhinoplasty/submucosal resection
172
Describe the route by which infection may spread from the nose to the conjunctiva
Infection within the nasal cavity tracking up through the ethmoid air cells (within the ethmoid sinus) to enter the orbit and infect the conjunctiva.
Another possible route is via the venous drainage. As the veins of the face are valveless infection could spread via the ophthalmic vein which drains the nose and the orbit.
173
Why may infection of the ethmoid sinus affect a patient's vision?
Air cells are in close proximity to the optic nerve therefore if infection spreads through the ethmoid sinus it may damage the nerve
174
Why is it important to drain a septal haematoma?
Septum is made up of cartilage which is an avascular structure and is supplied by the perichondrial layer. When a haematoma forms this layer is separated from the cartilage which means it is at risk of avascular necrosis. Therefore drainage followed by compression is important.
Furthermore, if a haematoma forms and then collapses there is a risk of nasal obstruction which could compromise the airways.
175
Why may dental work lead to maxillary sinusitis
Maxillary sinus is connected to the oral cavity via the front two molars. If damage to this plate occurs then a fistula may form which provides a route for bacteria to spread from the oral cavity.
176
What is a dangerous complication of infection spreading from dental work?
Sepsis
177
Name 5 risk factors for epistaxis
```
Trauma
Weakened septum
Mucosal drying
Medication side effects
Thinning of the nasal cavity
```
178
Describe the management ladder for epistaxis
1. Pinch cartilaginous part of the nose with thumb and index finger
2. Anterior packing
3. Posterior nasal packing
4. Surgical intervention - e.g. Ligation of sphenopalatine artery
179
Why does sinusitis cause headaches?
Inflammation causes swelling and congestion, including the blockage of drainage of the sinus. This leads to an increase in pressure which causes the headache symptoms.
180
What is the blood supply to the auricle?
Posterior auricular; superficial temporal & occipital arteries
These lay within the perichondrial layer
181
Why may external trauma cause "cauliflower ear"?
Blood supply within the perichondrial layer.
Trauma causes haematoma formation underneath this layer - separates the cartilage from the blood supply - avascular necrosis.
When haematoma disintegrates the area collapses down to form an irregular structure.
182
What is the innervation of:
a) auricle
b) external auditory meatus
a) greater auricular & lesser occipital branches of the facial and vagus nerves
b) auriculotemporal nerve (CNV) and auricular branch of the vagus nerve
183
Why do some people faint when cleaning their ears with cotton buds?
Innervation of the external auditory canal is partially from the vagus nerve.
Over stimulation or hypersensitivity of these nerve fibres can lead to a vasovagal response leading to bradycardia.
This can reduce blood pressure, causing fainting
184
State the proportions of the external auditory meatus that are:
a) bony
b) cartilaginous
a) medial 1/3
| b) lateral 2/3
185
What position does the ear need to be placed in for examination and why?
Up, out and backwards.
This is because the external auditory canal is sigmoid shape so to get the best view of the tympanic membrane it needs to be manipulated
186
What position do you need to move the child's ear into for examination?
Down and back
187
On otoscopy which quadrant is the cone of light found in?
Anterior inferior
188
Describe how the origin of the auditory ossicles differ
Malleus & incus - pharyngeal arch 1 (Meckel's cartilage)
| Stapes - pharyngeal arch 2 (Reichert's cartilage)
189
Explain why CNVII palsy can cause hyperacuisis
CNVII branches to give the nerve to the stapedius muscle
This muscle helps to dampen sounds therefore if the innervation is lost then this function is lost and there will be more sound transmitted through the ossicles
190
Why does blockage of the Eustachian tube cause the tympanic membrane to be sucked inwards?
The Eustachian tube helps to equalise the pressure in the middle ear by opening during swallowing.
If this is blocked then air will not be equalised.
As the mastoid air cells absorb air from the middle ear this is not equalised and therefore a negative pressure occurs. This causes the tympanic membrane to draw inwards.
191
Why can middle ear infections lead to loss of taste?
Facial nerve runs through the ear canal which is within the medial wall of the middle ear. Within the middle ear it gives the chorda tympani branch which supplies the anterior 2/3 with special sensory innervation.
Middle ear infections may damage the facial nerve or the chorda tympani branch which leads to loss of this innervation
192
The facial nerve gives off 3 branches in the Petrous temporal bone. Name them
Nerve to stapedius
Chorda tympani
Greater petrosal nerve
193
Describe how the innervation of the external and internal aspects of the tympanic membrane differ
External - auriculotemporal (V3)
| Internal - glossopharyngeal (CNIX)
194
Describe the route of infection from the middle ear to the mastoid air cells
Middle ear
Aditus to mastoid antrum
Mastoid antrum (posterior epitympanic recess)
Mastoid air cells
195
Explain why mastoiditis needs urgent treatment
The mastoid process is closesly related to the posterior cranial fossa
Infection could track back through the bone into the cranial fossa and cause meningitis which can be fetal
196
Describe how sound is transmitted from the tympanic membrane to the inner ear
Tympanic membrane -> handle of malleus
Body of malleus -> incus
Long limb of incus -> stapedius
Stapedius -> oval window of the vestibule of the inner ear
197
Why is the round window of the inner ear important?
Equalises pressure within the cochlear
198
State the artery which runs under the pterion which may be damaged due to trauma
Middle meningeal artery
199
Name the 4 bones which articulate at the pterion
Frontal
Sphenoid
Temporal
Parietal
200
Why can trauma at the pterion lead to raised ICP?
Rupture of the middle meningeal artery
Epidural haemorrhage
Grows towards the brain causing increased pressure
201
Why does raised ICP lead to Cushings triad?
Cushings triad = bradycardia; hypertension; dyspnoea
These all occur to compensate for raised intracranial pressure.
Blood pressure raises in an attempt to maintain cerebral perfusion
Bradycardia occurs due to distension of the arterioles leading to stimulation of baroreceptors which decrease heart rate
Dyspnoea is a sign of compression on the respiratory centres in the medulla - a sign of risk of hernia till
202
Name 3 bacteria which commonly cause otitis media
Streptococcus pneumoniae
Moraxella caterrhalis
Haemophillus influenzae
203
Explain why oral antibiotics are of little use for otitis media
Difficult to get to the site of infection
| Doesn't improve resolution time
204
Why may people suffering from otitis media lose their sense of taste?
If the infection damages the chorda tympani branch of CNVII which runs through the middle ear then they may lose loss of special sensory innervation to the anterior 2/3 of the tongue
205
What is cholesteatoma?
This is where inflammation of the Eustachian tube has prevented drainage of infection/dead skin cells which leads to necrotic debris. Lytic enzymes are produced which may lead to erosion of bone
206
What is OME and how does it appear on otoscopy?
Otitis media with effusion - where the bacteria are producing pus
Inverted tympanic membrane due to an increase in middle ear pressure
207
Why can OME be treated using a grommet?
Allows for drainage of the pus and equalisation of the middle ear pressure.
208
Give 2 types of vertigo & brief description
Benign positional paroxysmal vertigo - where calcium carbonate crystals have become dislodged and interfere with normal fluid movement
Menieres disease - excess accumulation of endolymph
209
What is the relative duration of:
a) BPPV
b) Ménière's disease
c) labyrinthitis
a) resolves without treatment - weeks-months
b) repeated attacks over several years. May have permanent damage after disease has resolved.
c)
210
A patient presents with what you suspect is sensorineural hearing loss. Describe the findings on weber's and rinne's tests
Rinne - air>bone
| Webers - normal ear
211
Explain why a patient with conductive hearing loss finds sound radiates to the affected ear on weber's test.
How does this differ in sensorineural?
Normal ear is still masked by external/environmental noises therefore conduction through the bone appears apparently louder. Note that noise is not travelling via the ossicles in this case.
Sensorineural webers = normal ear. This is because there is a problem with the processing of sound therefore sound is only transmitted through the normal ear.
212
Describe the articulation of the TMJ
Synovial hinge joint
Articular cartilage separates the joint into a superior and inferior cavity
Superior: convex and concave, between the articular cartilage and the mandibular fossa
Inferior: concave, between articular cartilage and the mandibular condyle
213
Why does the superior articular surface need to be longer than the inferior surface of the TMJ?
Articulates with a larger area - mandibular fossa
| This means that the cartilage needs to be longer to prevent anterior and posterior dislocations
214
Name the 3 ligaments of the TMJ
Lateral ligament
Temporomandibular ligament
Stylomandibular ligament
215
State the ligament with the following properties:
a) strongest ligament, prevents posterior dislocation
b) primary passive supporter of the mandible
c) thickening of the parotid capsule, separates the parotid from the submandibular gland
a) lateral ligament
b) Temporomandibular ligament
c) stylomandibular ligament
216
Name the muscles responsible for:
a) elevation
b) depression
c) protrusion
d) retrusion
e) lateral
Movements of the mandible
a) masseter, temporalis, medial pterygoid
b) lateral pterygoid and digastric
c) lateral pterygoid
d) posterior fibres of the temporalis
e) medial pterygoids
217
Describe the factors that prevent the TMJ from dislocating anteriorly
Articular tubercle of the temporal bone & string action of the temporalis muscle
218
Describe the potential consequences of TMJ dislocation
Lateral dislocation - fractures
Slight facial asymmetry - in superior paediatric dislocations
Damage to the cranial nerves (trigeminal passes through the infratemporal fossa)
219
State the muscular contents of the infratemporal fossa
Pterygoid muscles
| Inferior fibres of the temporalis muscle
220
Name the artery which enters the infratemporal fossa and the major branch. Where does this branch supply?
Maxillary artery - branches to give the middle meningeal artery which supplies the dura
221
Why may infection of the pterygoid plexus lead to damage to the eye?
Infection spreads to the cavernous sinus which may cause cavernous sinus thrombosis. Several cranial nerves pass lateral to the cavernous sinus - CNIII, CNIV, V1/2 and CNVI - all of which supply either the extraoccular muscles of the eye, parasympathetic innervation (CNIII) or sensory innervation.
222
Why may damage to the infratemporal fossa compromise the taste and general sensation to the tongue?
The linguinal nerve and other branches of the trigeminal nerve pass through this fossa. The lingual nerve provides general sensory innervation to the anterior 2/3 of the tongue.
Along with this nerve runs the chorda tympani which supplies the same area with special sensory (taste).
223
State the foramen which V3 exits the infratemporal fossa
Foramen ovale
224
Why can SVT be managed using a massage at the upper border of the thyroid cartilage?
At the superior border of the thyroid cartilage lies the carotid sinus.
Here there are baroreceptors which detect pressure.
External pressure on the carotid sinus (carotid sinus massage) stimulates a vasovagal response leading to reduced heart rate.
225
Explain why patients with a facial nerve palsy may need to protect their eyes until it heals?
The efferent response of the corneal reflex will be compromised therefore any dust etc that gathers will not be cleared.
Temporal and zygomatic branches of the facial nerve supply the orbicularis oculi muscle which causes blinking
226
How do you differentiate between a subdural and epidural haemorrhage on CT?
Epidural - biconvex haematoma
| Subdural - crescent shaped haematoma
227
Describe the different origins of the anterior and posterior pituitary
Posterior pituitary = neuroectoderm. It is an out picketing of the forebrain that has grown towards the sphenoid bone
Anterior pituitary = ectoderm. From the stomatodeum
228
What is the difference between the infundibulum and Rathke's pouch?
Infundibulum = out-pocketing of forebrain that has grown down towards the pharynx. It later becomes the posterior pituitary and the pars tubicularis
Rathke's pouch = area of stomatodeum ectoderm which grows outwards to the forebrain and becomes the anterior pituitary.
229
Name the tissue which gives rise to the pituitary stalk
Infundibulum
230
State the landmark that distinguishes the anterior 2/3 from the posterior 2/3 of the tongue
Sulcus terminalis
231
Describe how the pharyngeal arch components of the tongue develop to form the current structure of the tongue
The lateral lingual swellings of pharyngeal arch 1 grows down to cover the tuberculum impar. This gives the anterior 2/3 of the tongue.
The 3rd arch component of the cupola grows over the 2nd arch component which, along with some of the 4th arch, forms the posterior 1/3.
232
Explain the mechanism by which a child may be tongue tied
Tongue tied is where the lingual frenulum is too long.
| This occurs as a result of inadequate degeneration during the final stages of the tongue development.
233
Why is the anterior 2/3rds of the tongue innervated by the trigeminal and glossopharyngeal nerves
The anterior 2/3 of the tongue is derived from the 1st and 3rd pharyngeal arch.
The nerve associated with the 1st arch is the trigeminal
The nerve associated with the 3rd arch is the glossopharyngeal
234
State the embryological origin of the middle ear
Pharyngeal arch 1 (and some of 2)
235
Why must the chorda tympani pass through the middle ear
The chorda tympani innervates the anterior 2/3 of the tongue
However, the facial nerve is associated with pharyngeal arch 2 - which doesn't form any structure in the tongue.
This means that it has to go via the middle ear to supply the tongue with the innervation.
236
Why is the motor function of the tongue controlled by the hypoglossal nerve?
The intrinsic and extrinsic muscles of the tongue develop from myogenic precursors in the occipital somites which migrate into the tongue. They therefore bring their innervation with them which is CNXII
237
Describe the descent of the thyroid
The thyroid originates on the foramen cecum
It then bifurcates into a bilobular diverticulum, connected medially by the isthmus.
It then descends, anterior to the pharyngeal gut, hyoid bone and laryngeal cartilages, to its position over the crichoid cartilage.
It remains connected to the tongue during its descent by the thyroglossal duct, which resolves after descent is complete.
238
What week has the thyroid reached its target?
Week 7
239
Why are midline cysts probably a consequence of the descent of the thyroid
The thyroid descends through the midline attached to the tongue by the thyroglossal duct which usually disappears once the final position is established. If this remains then cysts formed.
Note: brachial cysts likely to be along the SCM
240
What is the Pathophysiology of Di-George syndrome?
Chromosomal abnormality leading to abnormal neural crest development.
241
What is CATCH 22?
Describes the characteristics of Di-George syndrome
```
Cardiac abnormalities (tetralogy of fallot)
Abnormal facies
Thymus atresia
Cleft palate
Hypocalcaemia/hypoparathyroidism
```
22 - chromosome abnormality
242
Why would you not give live vaccines to patients with Di-George syndrome?
Thymus atresia means that they lack a critical component of the adaptive immune system which is where T-cells mature.
243
What is the pathophysiology of CHARGE syndrome?
Heterozygous mutation of CHD7 which leads to reduced neural crest cell production
244
What does CHARGE stand for?
```
Coloboma - hole in the iris
Heart defects
Atresia of the choana
Retardation (growth and development)
Genital hypoplasia
Ear defects
```
245
State the boundaries and epithelium of the nasopharynx
Superior - base of the skull
Inferior - superior border of the soft palate
Anterior - posterior choanae
Posterior - C1
Epithelium = pseudostratified columnar ciliated (same as respiratory)
246
Why may adenoidectomy cause the atlanto-occipital joint to dislocate?
They are level with C1 vertebrae
247
Why may tonsillitis cause a palpable swelling at the angle of the jaw?
Palatine tonsils drain into the jugulo-digastric lymph nodes which are at the mandibular angle.
248
What are the boundaries of the hypopharynx?
Superior - superior edge of the epiglottis
Inferior - inferior edge of the crichoid cartilage
Anterior - larynx
Posterior - C3-6
249
Why are foreign bodies particularly prone to lodge in the hypopharynx?
Piriform fossae are small pouches either side of the oesophagus which may lead to foreign bodies getting stuck
250
Describe the function of the pharyngeal constrictors and why do they only overlap posteriorly?
Peristaltic contractions to move food into the oesophagus
They only overlap posteriorly to allow for food to pass within the pharynx and for the pharynx to distend if the food bolus is large.
251
Describe the process of swallowing
Voluntary placement on the back of the tongue.
Afferent stimulation (glossopharyngeal) sends signal to the swallowing centres
Efferent stimulation (vagus) leads to raising of the soft palate to occlude the nasopharynx and depression of the epiglottis to occlude the larynx.
Food bolus is pushed posteriorly and inferiorly into the oropharynx and the inner circular constrictor muscles move the bolus into the oesophagus.
Cricopharyngeus muscle relaxes. Oesophageal phase of swallowing begins.
252
What is the blood supply to the pharynx?
Facial, maxillary and lingual arteries.
| All branches of the external carotid artery.
253
How does the sensory innervation differ between different parts of the pharynx?
Nasopharynx - CNV
Oropharynx - CNIX
Hypopharynx - CNXII (think about tongue development, this is where the tongue attaches)
254
State some signs and symptoms of adenoid hypertrophy
```
Snoring
Obstructive sleep apnoea
Middle ear infections
Change of voice & breathing
Open mouth breathing
```
All due to occlusion of the nasopharynx or oropharynx
255
Why can adenoid hypertrophy lead to OME?
Occlusion of the Eustachian tube meaning that infection cannot drain effectively so builds up in the middle ear
256
What is the potential psychological consequences of OME?
Particularly in children:
Lack of development/progression at school
Frustration, which may lead to introvert behaviours
All as results of child being unable to hear.
257
Define sleep apnoea
Disordered breathing whilst asleep - one or more pauses in breathing or shallow breaths.
258
Why can sleep apnoea, if severe, lead to increased CVS stress?
Pauses in breathing may last for several minutes which leads to hypoxia.
This will stimulate responses to hypoxia including increased heart rate and blood pressure, causing stress on the heart and blood vessels (hypoxic vasoconstriction may occur)
Note: It will also stimulate the breathing centres which is why suffers may gasp loudly after an episode. This could have sociological implications
259
What are the potential complications of adenoidectomy?
Bleeding - vascular area and difficult to stop due to the location
Atlanto-occipital joint dislocation
Eustachian tube stenosis
The latter two are due to infections post-operation due to the removal of lymphoid tissue.
260
State an event/structure at:
a) C2
b) C4
c) C6
a) angle of the mandible
b) upper border of the thyroid cartilage & carotid bifurcation
c) crichoid cartilage
261
Explain the difference between stertor and stridor
Stertor - harsh discontinuous crackling sounds heard over the larynx/trachea. May also describe snoring
Stridor - intense continuous monophonic wheezes - accentuated during inspiration. Indicates upper airway obstruction
262
Describe the presentation of acute epiglottisis
Rapid onset
Sore throat
Odynophagia/dysphagia
Muffled voice
263
State 3 functions of the larynx
Phonation
Coughing
Respiration
264
Outline the borders of:
a) Supraglottis
b) Glottis
c) Subglottis
a) inferior border of epiglottis to the vestibular folds
b) vocal cords & 1cm below
c) lower border of the glottis to the lower border of the cricoid cartilage (C6)
265
What is the anatomical position of the vallecular and the importance of these structures
2 crypts either side of the midline at the base of the tongue.
Act as salivary storage to prevent premature activation of the swallowing reflex
266
Describe the anatomical position and importance of the piriform sinus
Small sacs lateral to the epiglottis
They form natural funnels to aid the flow of food into the oesophagus when the epiglottis is open
Clinically important as foreign objects often lodge here
267
Name 4 components of the laryngeal skeleton
Epiglottis
Arytenoid cartilage
Thyroid cartilage
Cricoid cartilage
268
What is the ligament which connects the laryngeal skeleton?
Thyrohyoid ligament
269
Describe how the components of the larynx articulate
Thyroid cartilage - superior articulation to the hyoid cartilage. Inferior articulation to the cricoid cartilage
Arytenoid cartilages sit on the superior surface of the cricoid cartilages and their apex connect to the corniculate cartilage
270
Name 4 structures which articulate with the arytenoids
Superiorly - corniculate cartilage
Inferior - cricoid cartilage
Vocal process - attaches to the vocal ligament
Muscular process - cricoarytenoid muscles
271
Which cartilage serves as attachment point for the corniculate and cuneiform cartilages
Arytenoid cartilage
272
What is the histology of the vocal cords?
True vocal cords - stratified squamous epithelium
| Reinke's - amorphous, rich in GAG - allows for vibration
273
Explain the importance of Reinke's space
Rich in glycosaminoglycans which allows for free vibration of the epithelium
274
Why does damage to the superior laryngeal nerve cause a weak voice?
Superior laryngeal nerve supplies the cricothyroid muscle which acts to tighten the vocal cord.
275
Give two methods of damage to the superior laryngeal nerve
Iatrogenic - e.g. Thyroidectomy
| Thyroid pathology - benign or malignant hypertrophy
276
Why is the cricoarytenoid an important muscle?
Causes ABduction of the vocal cords. These are the only muscles that do this action so are vital in respiration.
277
State the muscles responsible for aBduction and aDuction of the vocal cords
```
ABduction = posterior cricoarytenoid
ADduction = lateral cricoarytenoid
```
278
Why will damage to the recurrent laryngeal nerve lead to a weak cough reflex?
This nerve supplies the muscles that act on the vocal cord to cause abduction and Adduction. If these are disrupted either side then the patient will have difficulty closing their vocal cords to increase the intrathoracic pressure and also have difficulty opening their vocal cords quickly to cause the cough.
279
Describe the arterial supply to the larynx, stating the origin of the arteries
Superior laryngeal arteries - from the superior thyroid artery (branch of ECA)
and inferior laryngeal arteries - from the inferior thyroid artery (branch of the thyrocervical trunk from the brachiocephalic trunk)
280
Why may a carotid aneurysm lead to a weak voice?
Route of the recurrent laryngeal nerve is close to the carotid bifurcation where aneurysms commonly occur. This would lead to weakened muscles that act on the vocal cord.
281
Give 3 causes of hyperthyroidism
Primary hyperthyroidism - thyroid carcinoma, Graves disease (autoimmune)
Secondary hyperthyroidism - ectopic thyroid tissue;
282
Why is the inferior thyroid artery tortuous?
Very long route.
Thyrocervical trunk -> front of the vertebral artery -> medially behind the carotid sheath and sympathetic trunk. Divides into two branches at the lower border of the thyroid gland.
283
Give 4 events that occur at C6
Cricoid cartilage
Carotid bifurcation
Spinal accessory nerve and arteries enter the transverse foramina of the vertebral bodieso
284
Describe the possible complications of a coronary angiogram
Injury to the catheterised artery
Allergic reaction to the dye
Kidney damage
Stroke
285
Give 5 potential causes of recurrent laryngeal nerve damage
```
Apical lung tumour
Bronchial carcinoma
Idiopathic
Iatrogenic (e.g. Thyroidectomy)
Aortic aneurysm
```
286
State the most common type of laryngeal carcinoma
Squamous cell carcinoma
287
Why do patients with laryngeal carcinoma commonly present with otalgia?
Vagus nerve supplies the larynx with sensory innervation and the ear with sensory innervation.
Therefore laryngeal carcinoma may cause referred pain to the ear
288
Describe some other signs or symptoms of laryngeal carcinoma
Hoarseness of voice
Dysphagia
Weight loss
Loss of laryngeal crepitus
289
How is laryngeal carcinoma managed?
Radiotherapy/chemotherapy
| May require surgery - laryngectomy or pharyngo-laryngectomy
