Head neck and spine Flashcards
Which cervical level is the hyoid bone?
C3
Origin Insertion Action Nerve Special features Platysma
Lower border of mandible
Upper border of pec major and deltoid
Facial expression and opening the mouth
Cervical branch of facial nerve
Covers external jugular and anterior jugular veins. Blends with muscles of facial expression
What are the four parts of deep cervical fascia?
Investing
Prevertebral
Pretracheal
Carotid sheath
Where does the investing layer of the cervical fascia run and what does it attach to?
Splits around sternocleidomastoid and trapezius, subclavius, parotid gland and inferior belly of omohyoid- forming suprasternal space above jugular notch
Attaches to the skull, mandible and pelvic girdle
Forms roof of posterior triangle
Forms a fascial sling around omohyoid keeping it low in the beck
Fascia is pierced by external jugular vein
Where does the prevertebral fascia runs and what are its anatomical relations?
Sits in front of anterior vertebrae and prevertebral muscles (longus capitus, rectus capitus lateralis, longus colli, scalenus anterior, scalenus medius and levator scapula)
Floor of posterior triangle
All cervical nerve roots, cervical plexus, brachial plexus, and trunks, and the 3rd part of subclavian artery are deep to it
Lymph nodes of posterior triangle, accessory nerve, subclavian bein and axillary vein are superficial to it
Pierced by cutaneous branches of cervical plexus (lesser occipital, greater auricular, transverse cervical and supraclavicular nerves)
Where does the pretracheal fascia runs and what are its anatomical relations?
Sits behind infrahyoid strap muscles (sternothyroid, sternohyoid, omohyoid)
Splits around thyroid gland but only sticks on isthmus and 2/3/4 rings of trachea
Thymus and parathyroid gland lies deep
Pierced by thyroid vessels
Where does the carotid sheath run and what are its anatomical relations?
Surrounds common and internal arteries, internal jugular vein and vagus nerve
Sympathetic trunk lies posterior
Contains; common carotid (bifurcation at C4, no branches in the neck, lies medial to the sheath), internal jugular vein, vagus nerve, ansa cervicalis (imbedded within carotid sheath)
Free posteriorly
Carotid pulse felt by pressing common carotid at TP of C6
What are the key potential spaces of the neck?
Prevertebral space- pus from vertebrae can track down to superior mediastinum
Retropharyngeal space between prevertebral fascia and buccopharyngeal fascia-continuous with parapharyngeal space
Submandibular space- deep to investing fascia, communicates with mouth- relevant in Ludwig’s angina
Origin Insertion Action Nerve Special features Sternocleidomastoid
Two heads from manubrium of clavicle
Lateral surface of mastoid process and superior nuchal line of occipital bone
Contraction of one side tilts muscle towards ipsilateral shoulder and rotates head to face opposite side
C2 and 3 of spinal part of accessory nerve
Crossed by great auricular nerve, external jugular vein and transverse cervical nerve. Internal jugular vein lies between the two heads
Posterior surface is carotid sheath overlying scalenus anterior
What are the borders of the posterior triangle?
Posterior border of sternocleidomastoid Anterior border of trapezius Clavicle Roof is deep cervical fascia Floor is prevertebral fascia
What are the contents of the posterior triangle?
Lymph nodes Accessory nerve Inferior belly of omohyid Transverse cervical, suprascapular and 3rd part of subclavian artery External jugular vein Brachial plexus Cervical plexus C1-4 Cutaneous branches of cervical plexus (lesser occipital, greater auricular, transverse cervical and supraclavicular)
Origin
Insertion
Innervation
Digastric (suprahyoid muscle)
Posterior belly from medial surface of mastoid process. Intermediate tendon
to fibrous sling of hyoid bone
Anterior belly from inner surface of mandible
Posterior belly-facial nerve
Anterior belly- nerve to mylohyoid
Origin
Insertion
Innervation
Stylohyoid (suprahyoid muscle)
Back of styloid process
Splits to enclose digatsric and goes into hyoid bone
Facial nerve
Origin
Insertion
Innervation
Mylohyoid
Mandible back to 3rd molar
Hyoid bone
Mylohyoid nerve (only motor branch of posterior division of V3)
Origin
Insertion
Innervation
Geniohyoid
Mandible
Hyoid bone
Hypoglossal nerve (C1)
Deep to mylohyoid and superficial to tongue
Origin
Insertion
Innervation
Sternohyoid
Lower part of hyoid bone
Back of SCJ
Branch of ansa cervicalis (C1, C2, C3)
Origin
Insertion
Innervation
Omohyoid
Lateral part of inferior hyoid bone (lies between sternohyoid and thyrohyoid)
Passes beneath sternocleidomastoid to insert onto transverse scapular ligament and scapula
Has two bellies -superior and inferior
Branch of ansa cervicalis C1 C2 C3
Origin
Insertion
Innervation
Thyrohyoid
Under sternohyoid and omohyoid, originates from greater horn of hyoid bone
Thyroid cartilage
Hypoglossal nerve C1
Origin
Insertion
Innervation
Sternothyroid
Posterior surface of manubrium of sternum
Thyroid cartilage
Branch of ansa cervicalis
What lies lateral, medial and posterior to the thyroid gland?
Lateral-sternothryoid and sternohyoid superficially
Medial-larynx and upper trachea down to 6th tracheal ring, cricothyroid muscles, inferior constrictor of pharynx and external and recurrent laryngeal nerves
Posterior-parathyroid glands, common carotid artery, inferior thyroid artery (c6) ,left-thoracic duct at C7
Describe the course of the recurrent laryngeal nerves
Hooks around ligamentum arteriorsum on left and subclavian artery on the right
Goes under inferior constrictor of pharynx
Usually lies in the groove betwen trachea and oesophagus
Left-more likely to lie POSTERIOR to inferior thyroid artery
Right- equal chance of being posterior or anterior to inferior thyroid artery
Nerve splits at level of isthmus into anterior (motor) and posterior (sensory)
1-2% of non recurrent right laryngeal nerve-abnormal right subclavian artery
What does the external laryngeal nerve supply?
Runs behind superior thyroid artery
Supplies cricothyroid
What is the blood supply of the thyroid?
Superior thyroid artery- branch of external carotid-pierces pretracheal fascia
Inferior thyroid artery- thyrocervical trunk- from thyrocervical trunk- pierces pretracheal fascia
Venous return into superior thyroid vein (internal jugular), middle thyroid (internal jugular) and inferior thyroid (left brachiocephalic vein)
What is the nerve supply of thyroid?
Sympathetic from superior middle and inferior cervical ganglia
Thyroid glands weighs 25 grams
Where are the parathyroid glands?
Posterior to thyroid
90% of people have 4 glands (50 grams each)
Superior gland- 1st tracheal ring
Inferior gland- variable position sometimes behind lower pole below ITA
Supplied by ITA
What is the weird embryological development of the parathyroid glands?
Superior gland- aka parathyroid IV as comes from 4th pharyngeal pouch
Inferior gland- parathyroid III developed from 3rd pouch, but displaced caudally by descent of thymus so always ends up in weird places
Where is the oesophagus in relation to the thyroid and vessels of the neck?
Begins at C6
Attached to lower margin of cricoid cartilage
2 parts cervical and thoracic
Posterior- recurrent laryngeal nerve
Lateral- carotid sheath
Isthmus of thyroid adherent to 2/3/4 tracheal rings
Anterior-inferior thyroid vein and anterior jugular venous arch
Where is elective tracheostomy performed?
Transverse skin incision is made 2cm below cricoid cartilage
Between 2 sternohyoid muscles down sternothyroid muscle
Isthmus of thyroid divided and opening made by removing part of 2-3 tracheal rings
How long is the submandibular gland and what is its innervation?
5cm long
Superficial and deep part
Cell bodies in submandibular ganglion with preganglionic fibres in superior salivary nucleus in pons via nervus intermedius, chorda tympani and lingual nerve
Any incision must be 4cm away from mandible to avoid marginal mandibular branch of the facial nerve
List the 6 branches of the external carotid artery from C4 before it reaches the parotid gland
Superior thyroid artery Lingual artery Facial artery Occipital Posterior auricular Ascending pharyngeal
Lies in front of sternocleidomastoid muscle accept initially
Some Large Facials Open Pussies up
What structures cross over internal carotid artery?
Crossed by lingual and facial veins, occipital artery and glossopharyngeal nerve
Posterior digastric, stylohyoid, posterior auricular artery
Where is the internal carotid in relation to the external carotid artery, vagus nerve and internal jugular vein?
Internal carotid initially lateral, then medial and deeper to external carotid
Ascends upwards in carotid sheath
IJV lies laterally within sheath
Vagus nerve is between artery and IJV
Behind the carotid trunk is sympathetic trunk (outside sheath)
carotid sinus lies at commencement- carotid body chemoreceptors
Internal carotid artery has no branches in the neck
Describe the course of the internal jugular vein
Emerges in the posterior compartment of jugular foramen
Lies on lateral mass of atlas
Lies on thoracic duct at C7
Crossed by accessory nerve
Crossed by omohyoid
First tributary-inferior petrosal sinus
Sits laterally in carotid sheath (starts off posteriorly)
What are the tributaries of the internal jugular vein?
Pharyngeal plexus Facial Lingual Superior thyroid vein Middle thyroid vein
What are the borders of the carotid triangle?
Sternocleidomastoid/ posterior belly of digastric
Superior belly of omohyoid
What are the borders of the anterior triangle?
Sternocleidomastoid
mandible
Midline
what are the borders of the digastric/submandibular triangle?
Mandible
Anterior and posterior bellies of digastric
What are the borders of the submental triangle?
Anterior body of digastrics
Body of hyoid bone
Midline
What are the boundaries of the muscular triangle?
Sternocleidomastoid
Superior belly of omohyoid
Midline
What is the contents of the carotid triangle?
Arteries: Bifurcation of common carotid Branches of external carotid (except pharyngeal artery) Nerves: Hypoglossal Internal laryngeal nerve External laryngeal nerve Lymph nodes
What are the contents of the digastric triangle?
Submandibular gland Lymph nodes Facial a +v Submental a+v Mylohyoid artery Hypoglossal nerve mylohyoid nerve
What are the contents of the submental triangle?
Anterior jugular vein
Lymph nodes
What are the contents of the muscular triangle?
Larynx
Thyroid gland
Lymph nodes
What are the prevertebral muscles of the neck?
Rectus capitus anterior Rectus capitus lateralis Longus capitus Longus colli All covered by prevertebral fascia
Where does the carotid sympathetic trunk lie and what does it consist of?
Sits anterior to prevertebral fascia
posterior to carotid sheath
Consists of
-superior cervical ganglion C1-4
-middle cervical ganglion C5-6
-inferior cervical ganglion C7-8
-stellate/cervicothoracic ganglion C7-T1
Somatic branches to cervical (C1-4)and brachial plexuses (C5-T1)
Visceral from each ganglion to cardiac plexus
Causes horner’s syndrome (miosis, ptosis and no sweating of forehead)
Origin
Insertion
Nerve
Scalenus anterior
C3-6 anterior tubercles
Scalene tubercle of 1st rib
C4-6 anterior rami nerve
What lies anterior to scalenus anterior?
Phrenic nerve Acsending cervical artery Transverse cervical and suprascapular arteries Vagus nerve R) recurrent laryngeal artery Internal jugular vein Subclavian vein
What lies medial to the scalenus anterior?
Longus colli Makes a pyramidal space; -base is subclavian artery -apex is common carotid artery -stellate ganglion -vertebral artery and veins -inferior thyroid artery at C6 -thoracic duct -first part of subclavian artery and its 3 branches (vertebral artery, thyrocervical trunk, internal thoracic artery) -Vertebral vein
What are the branches of the thyrocervical trunk?
Superficial cervical (transverse cervical if gives off dorsal scapula)
Suprascapular
Inferior thyroid
Ascending cervical
What lies posterior to scalenus anterior?
Second part of subclavian artery-only branch is costocervical trunk- divides into superior intercostal artery and deep cervical artery
Anterior rami of lower cervical and first thoracic nerves
what lies laterally to scalenus anterior?
Trunks of brachial plexus
Third part of subclavian artery- gives off dorsal scapula
Which nerve is the motor supply to the face?
Facial nerve
No sensory fibres
Which nerve is the proprioceptive impulses of the face?
Trigeminal nerve
Describe the course of the facial nerve
Emerges from base of skull through stylomastoid foramen
Branches:
Posterior auricular (occipital belly of occipitofrontalis)
muscular branch to posterior belly of digastric and stylohyoid
Goes into parotid gland= divides into pes anserinus;
Temporal
Zygomatic
Buccal
Marginal mandibular (20% passes into neck below mandible)
Cervical
Which is the only part of the face that has sensation which does not come from the facial nerve?
Over angle of mandible
-greater auricular nerve c2 C3
Describe the sensory supply of the ophthalmic nerve (V1)?
Lacrimal- lateral upper eyelid Supraorbital- medial end of orbit Supratrochlear-middle of forehead Infratrochlear-skin over upper eyelid External nasal-external nose down to tip
Describe the sensory supply of the maxillary V2 nerve?
Infraorbital nerve- lower eyelid
Zygomaticofacial- zygomatic bone
Zygomaticotemporal- hairless part of temple
Describe the sensory supply of the mandibular nerve V3?
Auriculotemporal nerve; external acoustic meatus and hairy skin over temple
Buccal- cheek
Mental nerve- through mental foramen
What is the blood supply of the face?
Facial artery (3rd branch of external carotid artery)
Goes up side wall of pharynx then hooks over posterior belly of digastric and hits mandibular gland
Hooks over inferior border of mandible at masseter
Then up to medial angle of the eye
Temple supplied by superficial temporal (terminating branch of carotid)
Forehead supplied by orbit by ophthalmic artery
What is the venous drainage of the face?
Forehead-facial vein
Temple- superficial temporal vein which forms retromandibular vein
Facial vein communicates with cavernous sinus and ophthalmic veins
If facial vein is blocked blood can flow through orbit into cavernous sinus
Describe the 5 layers of the scalp
Skin is thickest in the body Connective tissue Aponeurosis Loose areolar tissue Pericranium is firmly attached to suture lines
What is the origin of the occipitofrontalis muscle
Occipitalis- arises from highest nuchal line
Frontalis- arises from the front of the aponeurosis-has no bony attachment
R and L frontalis muscles meet in the midline- occipitalis does not
Innervated by facial nerve
Occipitalis- posterior auricular
Frontalis- temporal and zygomatic branches
What is the blood supply of the scalp?
External carotid via occipital, posterior auricular and superficial temporal
Internal carotid via supratrochlear and supraorbital branches
Freely anastomose
Bones of vault supplied by middle meningeal artery (therefore necrosis does not occur in scalping)
What can ear infections cause death?
Posterior auricular vein drains scalp behind the ear and receives mastoid emissary vein from sigmoid sinus
Retrograde thrombosis of cerebellar and medullary veins
Which bones meet at the pterion?
Frontal
Parietal
Temporal
Sphenoid
Which nerves cross the zygomatic arch?
Auriculotemporal nerve
Temporal and zygomatic branches of facial nerve
Which is the only muscle to retract the mandible?
Temporalis
Converges towards coronoid process of mandible
Inserts on inner plate of the bone
Innervated by 2 deep temporal branches of the mandibular nerve
Blood supply temporal branches of maxillary artery
What runs between the 3 heads of the masseter muscle?
Between superficial and intermediate- superficial temporal or transverse facial artery
Between intermediate and deep- masseteric nerve (anterior division of mandibular nerve)
Muscle inserts onto mandibular ramus