Head & Neck Flashcards
What veins and muscle is contained in the superficial fascia of the neck?
Contains Platysma Muscle (innervated by cervical branch of facial nerve. Attaches lower mandible and muscles of face to the pec major and deltoid)
Contains Superficial veins (External Jugular and anterior jugular vein)
Contains cutaneous nerves
What are the 3 layers of deep fascia in the neck and what do they surround?
Investing Layer - Underlying subcutaneous fat. Splits around the Sternocleidomastoid, trapezius and parotid gland. Attaches the hyoid bone and meets the ligamentum niche posteriorly. (Pierced by external and anterior jugular veins)
Pre-Tracheal Fascia - Encloses thyroid gland, trachea, oesophagus and fuses laterally with carotid sheath.
Pre-vertebral Fascia - Surrounds vertebral column, pre-vertebral muscles, scalene muscles and deep back muscles.
Describe the following as either deep or superficial to the pre-vertebral fascia
- Cervical nerve roots
- 3rd part of subclavian artery
- brachial plexus
- accessory nerve
- lymph nodes of posterior triangle
Cervical nerve roots, 3rd part of subclavian artery and brachial plexus are deep to the fascia
Accessory nerve and lymph nodes of posterior triangle are superficial to the fascia
What lies within the carotid sheath?
Lower Part:
Lateral: Internal Jugular Vein
Middle: Vagus Nerve and ansa cervicales
Medial: Common carotid
*Note the cervical sympathetic trunk lies behind the carotid sheath (between carotid sheath and pre-vertebral fascia) and the Sansa cervicalis lies anterior
Upper Part (Begins approx. C3/4):
Internal carotid artery, internal jugular and CN XI, X, XI, XII
What are the 3 Tissue Spaces of the neck and what are the anterior and posterior fascia bounding them?
- Pre-Vertebral Space (Within the pre-vertebral fascia, from base of skull to level of T3)
- Pre-Tracheal Space (Between investing layer and pre-tracheal layer)
- Retropharyngeal Space (Between the buccopharyngeal fascia (anterior) and pre-vertebral fascia (posterior). Extends anteriorly to the submandibular space and infection here causes Ludwigs angina .
Border and contents of Posterior Triangle
Border
- Anterior: Sternocleidomastoid
- Posterior: Trapezius
- Inferior: Middle 1/3rd Clavicle
- Apex: Superior nuchal line
- Roof: Investing layer
- Floor: Pre-vertebral fascia
Contents
- V: External Jugular Vein (joins subclavian vein at bottom)
- N: Brachial Plexus (at base), Cutaneous branches of Cervical Plexus (3rd and 4th cervical nerve), Accessory Nerve
- L: Occipital nodes
- M: Omo-hyoid muscle
Anterior Triangle Borders and Contents
Borders
- Superior: Mandible
- Lateral: Sternocleidomastoid
- Medial: Sagittal line down midline of neck
- Roof: Investing fascia
- Floor: Visceral fascia
Contents
- M: Supra-hyoid and infrahyoid muscles
- N: CN VII, IX, X, XI, XII, Ansa cervicales
- A+V: Common carotid, internal jugular vein
- V: Thyroid, Parathyroid, Trachea, Oesophagus
Suprahyoid Muscles
Infrahyoid muscles
Thyroid gland vascular supply
- Superior thyroid artery (branch of external carotid artery)
- Inferior thyroid artery (From thyrocervical trunk which is branch of brachiocephalic)
What is the nerve supply to the thyroid gland and what other nerve that doesn’t innervate it is at risk of injury in thyroidectomies?
Innervation:
- Parasympathetic - Vagus nerve
- Sympathetic - Middle cervical ganglion
Injury risk - external laryngeal nerve lies behind superior thyroid artery to supply cricothyroid muscle
What is the innervation and blood supply to the trachea?
Innervation - recurrent laryngeal nerve
Arterial - Inferior thyroid a.
Epithelium lining trachea?
pseudo stratified columnar epithelium, with goblet cells producing mucus
What vertebral level does the trachea and oesophagus begin?
C6
What are the layers of the oesophagus?
Adventitia
Muscular Layer (Upper 1/3 Striated, Middle 1/3 Striated and smooth, Lower 1/3 Smooth)
Submucosa
Mucosa (Non-keritinised stratified squamous)
Describe the two oesophageal sphincters
Upper:
Produced by the cricopharyngeus muscle
Lower:
Physiological sphincter (No defining anatomy - just change from oesophageal to gastric mucosa)
At level of T11 (enters abdomen at T10) the change to abdominal pressures created a physiological sphincter
Arterial and venous supply to oesophagus
Arterial
- Thoracic –> Branches of thoracic aorta and inferior thyroid artery
- Abdominal –> gastric artery
Venous
- Thoracic –> Azygous veins and inferior thyroid vein
- Abdominal –> Porto-systemic anastomosis
Innervation of oesophagus
Vagus nerve
(upper striated part from nucleus ambiguous within medulla)
(Lower smooth from dorsal motor nucleus)
When does common carotid divide into internal and external carotids?
Just below level of angle of mandible
Branches of External Carotid Artery
Some Anatomists Love Freaking Out Poor Medical Students
Superior thyroid artery
Ascending Pharyngeal Artery
Lingual Artery
Facial Artery
Occipital artery
Posterior auricular artery
Maxillary artery
Superficial temporal artery
The external carotid artery lies superficial to the middle constrictor and stylopharyngeus. What two suprahyoid muscles does it lie immediately deep to?
Posterior belly of digastric, Stylohyoid
Structures that pass between the external and internal carotid arteries
- Glossopharyngeal nerve
- Pharyngeal branch of vagus
- Portion of the parotid gland
- Stylopharyngeus muscle
What sinuses form the internal jugular vein and what
Sigmoid sinus and inferior petrosal sinus
What anterior rami are the cervical plexus formed by and what were their motor and sensory branches
Formed by anterior rami of C1-4
Muscular Branches (Phrenic nerve, ansa cervicales, nerves to geniohyoid and thyrohyoid and a few other musclualr branches)
Sensory branches (Greater auricular nerve, lesser occipital nerve, transverse cervical nerve, supraclavicular nerves)
Where does the Cervical Sympathetic Trunk Lie within the neck and what level of the spinal cord does it originate?
Originates from T1-6
Has 3 ganglia (superior, middle, inferior)
Lies anterior to longus Colli and longus capaitis (pre-vertebral muscles) and begin the common carotid artery
In relation to the anterior scalene muscle, how does the subclavian artery run (posterior or anterior to it)?
Posterior to anterior scalene
At what level does the vertebral arteries enter the foramen of the cervical transverse processes?
C6
What arteries does the Vertebral artery give off?
- Posterior inferior cerebellar artery
- Anterior and posterior spinal arteries
- Meningeal arteries (Supplies fall cerebelli)
What are the 3 branches of the 1st part of the subclavian artery
- Vertebral arteries
- Thyrocervical trunk
(Gives off inferior thyroid artery, supra scapular artery and transverse cervical artery) - Internal thoracic artery
2nd part (Costocervical a.)
3rd part (Dorsal Scapula a.)
Describe the the pathway of the vagus nerve in the neck
Leaves skull at jugular foramen
Travels down neck in carotid sheath between internal carotid and internal jugular
At root of neck it passes in front of subclavian artery and behind subclavian vein to enter thorax
Describe the pathway of the right and left recurrent laryngeal nerves
Right - wraps around first part of subclavian artery and runs upward in groove between trachea and oesophagus
Left - Passes around arch of aorta and runs upwards along the trachea
What are the muscles of mastication and their innervation?
Describe the pathway of the facial nerve
Intracranial:
Arises in pons, exits through internal acoustic meatus
Gives rise to 3 branches in the facial canal (greater petrosal nerve, nerve to Stapedius, Chorda tympani)
Exits skull through stylomastoid foramen
Extracranial:
Gives off posterior auricular nerve, nerve to posterior belly of digastric and nerve to Stylohyoid
Main trunk of nerve continues anterior, inferiorly to the parotid gland (which it doesn’t innervate - CN IX does)
Within the parotid it splits into its 5 terminal branches (Temporal, zygomatic, buccal, marginal mandibular, cervical)
Describe the sensation to the face
Trigeminal nerve
- CN VI Ophthalmic
- CN VII Maxillary
- CN VIII Mandibular
Back of head are cervical nerves
- Lesser occipital, greater auricular, greater occipital (C2)
Describe the arterial supply to the face
External Carotid Artery Branches
–> Facial Artery
–> Superficial temporal artery
Internal Carotid Artery –> Ophthalmic artery (gives off supraorbital and supratrochlear)
Describe the venous return of the face
Superficial temporal vein and maxillary vein join to form retromandibular vein
Retromandbular vein and posterior auricular vein join to form external jugular vein
Internal jugular vein receives blood from facial, lingual, occipital, superior and middle thyroid arteries
What are the 5 layers of the scalp
Skin
Connective tissue (dense)
Aponeurotic Layer - Occipitofrontalis (Supplied by facial n.)
Loose Connective Tissue
Pericranium
What Structures Lie within the Parotid Gland
- Parotid Duct
- Facial nerve Branches
- External Carotid Terminal Branches (Superficial temporal and maxillary)
-Retromandibular vein
What innervates the parotid gland
Parasympathetic (Increases saliva secretion)
–> Glosospharyngeal (Via otic ganglion and then hitchhikes on auriculotemporal n.)
*Facial nerve goes through it and does not innervate it
Sympathetic (superior cervical ganglion)
Sensory supply
–> Auriculotemporal nerve (Branch of CN V3)
Where are the openings of ducts into the nasal cavity
Inferior meatus
–> Nasolacrimal Duct
Superior Meatus
–> Posterior ethmoidal cells
Middle Meatus (the rest)
–> Frontal sinuses, maxillary sinuses, anterior and middle ethmoidal cells
*Eustachian tube opens posteriorly in the nasopharynx
Describe the blood supply to the nose
Mainly the sphenopalatine artery (branch of maxillary). Anatomoses with greater palatine artery over the septum creating Kieselback’s plexus (Little’s area) which is the most common site for anterior epistaxis
What are the muscles of the soft palate and what innervates them?
5 pairs of muscles that act as a valve and prevent reflux
- Tensor veli palatini
- Levator veli palatini
- palatopharyngeus
- palatoglossus
- musculus uvulae
All innervated by the Vagus Nerve, except tensor veli palatini (innervated by CN V3)
What epithelium lines the tongue and describe the papillae of the tongue
Epithelium - Stratified squamous keratinising epithelium roughened with papillae
- Filiform papillae (Minute conical projections)
- Fungiform papillae (Discrete pink pinheads)
- Foliate papillae (Posterior tongue, home to many taste buds)
- Vallate papillae (V-shaped pointing backwards)
Innervation of tongue
Sensation:
Anterior 2/3rds
- Taste - facial n. CNVII (Chorda tympani)
- General - CN V3
Posterior 1/3
- General and taste - glossopharyngeal n. (CNIX)
Motor:
Hypoglossal n. (CN XII)
What 3 nerve cross the submandibular gland
- facial nerve (marginal mandibular branch)
- Lingual nerve
- Hypoglossal nerve
What are the pharyngeal muscles and their innervation
Constrictors
- Superior, middle and inferior
Longitudinal
- Salpingopharyngeus
- Palatopharyngeus
- Stylopharyngeus
All innervated by vagus nerve except stylopharyngeus (glossopharnygeal nerve)
What structures pass between the constrictor pharyngeal muscles
Above the superior constrictor
o Tensor and levator veli palatini muscles
Between superior and middle constrictors
o Stylopharyngeus muscle, glossopharyngeal nerve, lingual nerve and vessels
Between middle and inferior constrictors
o Internal laryngeal vessels and nerve
Below inferior constrictor
o Recurrent laryngeal nerve and inferior laryngeal vessels
Sensory innervation of the 3 divisions of the pharynx
Nasopharynx - Maxillary N (CN V2)
Oropharynx - Glossopharyngeal n. (CN IX)
Laryngopharynx (Vagus n.)
Describe the arterial and venous vessels of the larynx
Arterial
- Superior laryngeal artery (branch of superior thyroid from external carotid)
- Inferior laryngeal artery (branch of inferior thyroid artery from thyrocervical trunk off subclavian)
Venous
- Superior laryngeal vein (drains to internal jugular v.)
- Inferior laryngeal vein (Drains to inferior thyroid then brachiocephalic vein)
Innervation of larynx
Recurrent laryngeal nerve (Intrinsic muscles of larynx except cricothyroid and sensation in infra glottis)
Superior laryngeal nerve (Cricothyroid muscle and supra glottis sensation)
Intrinsic muscles of the larynx, their innervation and action
Cricothyroid (A: Stretches VC, I: Superior laryngeal n.)
*Rest innervated by recurrent laryngeal
- Thyroarytenoid (A. Relaxes VC)
- Posterior cricoarytenoid (A: Abducts)
- Lateral cricoarytenoid (A: Adducts)
- Transverse and oblique arytenoids (Adducts)
What nerves innervate the tympanic membrane
Auriculotemporal nerve (CNV3)
Vagus Nerve
Describe the bone structure of the vertebrae and the main differences between cervical/ thoracic and lumbar vertebrae
Cervical
- 7 vertebrae
- Bifid spinous processes
- Triangular vertebral foramen
- Transferve foramina (for vertebral arteries)
Thoracic
- 12 vertebrae
- 2 demi-facets on the body superiorly and inferiorly that articulate with the ribs
- Transverse processes have costal facets articulating with ribs
- Spinous processes are oriented inferiorly
Lumbar
- 5 vertebrae
- large bodies
- triangular vertebral foramen
Describe the ligaments of the spine
When does the spinal cord end and what’s this called?
Conus medullar is - ends at L1 in adults (L3/4 in children). Then the caudal equina which is just nerve roots continues on.
Describe the Spinal Meninges
Outer - Dura Mater
- Separated from vertebral canal wall by epidural space (which contains fat and venous plexus)
Middle - Arachnoid Mater
- separated from Pia by subarachnoid space containing CSF
Inner - Pia Mater
- Covers spinal cord and nerve roots
- Thickens to form the denticulate ligaments
What are the following foramen and what pass through them?
Optic Canal
(Optic n. CNII)
Superior Orbital Fissure
(Occulomotor CNIII, Trochlear n. CN IV, Abducens n. VI, Ophthalmic n. CNV1)
Foramen Rotundum
(Maxillary n. CNV2)
Foramen Ovale
(Mandibular n. CNV3)
Foramen Spinosum
(Middle meningeal a.)
Carotid Canal
(Internal carotid a.)
Internal acoustic meatus
(Facial n. and vestibulocochlear n.)
Jugular foramen
(Glossopharyngeal n., Vagus n. Accessory n.)
Hypoglossal foramen
(hypoglossal n.)
Foramen magnum
(Medulla, vertebral arteries, spinal accessory nerve)
List the first 7 cranial nerves and their function
List cranial nerves 8-12 and their functions
Describe the main lobes, gyri and sulci of the brain
Describe the ventricular system
Describe the circle of willis
Describe the venous sinus system of the brain
What contents are in the cavernous sinus
Describe the descending corticospinal tract
Begins cerebral cortex
Converge and descend internal capsule
Through to medulla and divides into two tracts
i. Lateral CS - decussates and descends spinal cord to ventral horn
ii. Anterior CS - remains isplilateral and decussates in spinal cord at level of ventral horn
Describe the dorsal column- medial leminiscal pathway
Fine touch, vibration and proprioception
Describe the Spinothalamic Tract
Lateral: Carries pain and temperature
Anterior: Crude touch and pressure
