002 the superficial structures of the neck Flashcards
what structures are in the anterior compartment of the neck?
- digestive, upper respiratory tract, neurovasculature
what structures are in the posterior compartment of the neck?
- vertebral column and associated musculature
what is the deep cervical fascia?
- encloses all neck compartments
- beneath superficial cervical fascia and platysma
- runs from the clavicle up to the mandible
what are the 3 layers of deep cervical fascia?
- superficial/investigating/anterior
- middle/pretracheal
- deep/prevertebral/posterior
what is in the superficial/anterior/investing layer of deep cervical fascia?
- encloses trapezius, sternocleidomastoid and carotid sheath
- anteriorly merges with fascia around infrahyoid muscles
- superiorly to external occipital protuberance and superior nuchal line
- laterally to mastoid process and zygomatic arch
- inferiorly to spine of scapula, clavicle and sternum
what is in the middle/pretracheal layer?
- encloses infrahyoid muscles, thyroid gland, trachea and oesophagus
- superiorly at hyoid bone
- inferiorly upper thoracic cavity
- separated pharynx and pretracheal layer
what is in the deep/prevertebral layer of the deep cervical fascia?
- encloses the erector spinae, prevertebral muscles, vertebral columnand scalene muscles
- superiorly /posteriorly = circular line around base of skull, superior nuchal line/occipital protuberance
- anteriorly = bottom of occipital bone and carotid canal and transverse processes of vertebrae
- laterally = mastoid process
what is the clinical significance of the spaces between the deep cervical fascia layers?
- fluid lies between these layers and can easily be infected/spread
how many cervical spines are there?
7
what are the names of c1 and c2?
c1 = atlas
c2 = axis
what features do cervical spine have?
- bifurcated spinous process
- coronal superior/inferior articular facets
- transverse process/foramen
- vertebral canal
- body except for atlas
-uncinate process to join bodies - anterior and posterior processes
what are the 3 different spaces between the deep cervical fascia?
- pretracheal space = between the superficial/investing fascia layer and the pretrachial fascia layer
- retropharyngeal space = between buccopharyngeal fascia and prevertebral fascia
- fascial space = within prevertebral layer, this layer splits into 2 laminae to create fascial space from base of skull to diaphragm
what are the 3 scalene muscles and what do they do?
- anterior = elevation of rib 1 and lateral bending of neck
- middle = elevation of rib 1 and lateral bending of neck
- posterior = elevation of rib 2 and lateral bending of neck
what are the origins/insertions of the 3 scalene muscles?
- all deep to sternocleidomastoid and omohyoid
- anterior = transverse processes of C3-6 to upper surface of rib 1
- middle = transverse processes of C2-6 to upper surface of rib 1
- posterior = transverse processes of C4-6 to upper surface of rib 2
what are the scalene muscles innervated by?
- anterior rami of C3-7
what are the suprahyoid muscles and what do they do?
- stylohyoid, digastric, mylohyoid, geniohyoid
- pulls hyoid upwards and back
what are the attachments of the stylohyoid?
- from styloid process of temporal bone to lateral area of hyoid bone
what is the innervation and function of the stylohyoid?
- facial nerve
- pulls hyoid bone upwards and backwards
what are the attachments of the digastric muscles?
- anterior belly = digastric fossa lower inside of mandible to tendon between bellies
- posterior belly = tendon to mastoid process of temporal bone
what is the innervation and functions of the digastric muscles?
anterior = mylohyoid nerve (mandibular nerve branch), opens mouth by lowering mandible
posterior = fascial nerve
- when mandible fixed = raise hyoid
- when hyoid fixed = lower mandible and open mouth
what are the attachments of the mylohyoid
- mylohyoid line on mandible to hyoid bone
what is the innervation and action of mylohyoid?
mylohyoid nerve (mandibular nerve branch)
- supports elevation of mouth / hyoid
what are the attachments of geniohyoid?
- inferior mental spine on inner surface of mandible to anterior surface of hyoid
what is the innervation and action of geniohyoid?
- hypoglossal nerve (C1)
- fixed mandible = hyoid up and forward
- fixed hyoid = mandible down and inwards
what are the infrahyoid muscles?
- aka strap muscles
- sternohyoid, omohyoid, thyrohyoid, sternohyoid
what are the attachments of the sternohyoid?
- sternoclavicular joint to the hyoid bone
what is the innervation and action of the sternohyoid?
- ansa cervicalis (C1-3)
- depresses hyoid after swallowing
what are the attachments of the omohyoid?
- superior border of scapula to the lower border of hyoid
what is the innervation and action of the omohyoid?
- ansa cervicalis (C1-3)
- depresses and fixes hyoid bone
what are the attachments for the thyrohyoid?
- deep to sternohyoid
- oblique line on thyroid cartilage to greater horn of hyoid
what is the innervation and action of the thyrohyoid?
- hypoglossal nerve (C1)
- depresses hyoid bone, when hyoid bone fixed, raises larynx
what are the attachments of the sternothyroid?
- deep to sternohyoid
- posterior surface of manubrium, sternum to the oblique line on thyroid cartilage
what is the innervation and action of the sternohyoid?
- ansa cervicalis (C1-3)
- draws larynx down
what are the attachments of the trapezius?
- superior nuchal line, external occipital protuberance, spinous processes of C7-T12
to lateral 1/3 of clavicle, acromion and spine of scapula
what is the innervation of the trapezius and what does it do?
- accessory nerve (C3,4)
- rotates scapula during abduction of arm
what are the origins of the sternocleidomastoid heads?
- sternal head = upper part of anterior surface of manubrium, sternum
- clavicular head = superior surface of medial 1/3 of clavicle
what are the insertions of the sternocleidomastoid heads?
- sternal head = lateral 1/2 of superior nuchal line
- clavicular head = lateral surface of mastoid process
what is the innervation and action of the sternocleidomastoid?
-accessory nerve (C2-4)
- lateral bending of neck, rotate head, neck flexion, head extension
what is the main artery supplying the head and neck?
- carotid arteries from aorta
what is the main vein draining the head and neck?
- jugular veins, into the superior vena cava
what are the 2 branches of the common carotid
- divides into the internal and external carotids near the superior border of the thyroid cartilage
describe the internal carotid artery
- internal = continues upwards an enters skull through carotid canal without releasing any branches, supplies cerebrum and meninges
describe the external carotid artery
- supplies the larynx, pharynx, mouth, nose, scalp, skill , meninges and some of thyroid gland via many branches
what is the carotid sinus?
- dilation of the start of the internal carotid artery, behind the bifurcation of the common carotid artery
- sensitive to arterial blood pressure changes as it contains baro receptors
- can also feel pulse here
what is the carotid body?
- very close to carotid sinus (not visible to naked eye)
- containers chemoreceptors that monitor O2, CO2, pH and temperature of arterial blood
what nerves supply the carotid sinus and body?
- glossopharyngeal nerve, cervical sympathetic trunk and vagus nerve
describe the arterial branching from the aorta on the right side of the body to the head and neck
- aorta –> right brachiocephalic artery splits into the right subclavian artery and right common carotid
- right common carotid splits into internal and external branches
- right subclavian has a right thyrocervical trunk and right vertebral artery branching off it
describe the arterial branching from the aorta on the left side of the body to the head and neck
- aorta –> left subclavian artery and left common carotid
- left common carotid splits into internal and external branches
- left subclavian has left thyrocervical trunk and left vertebral arteries
what are the 2 main lymphatic ducts in the body?
- right lymphatic duct (right arm, chest and right side of head)
- thoracic duct ( all of legs and abdomen, left chest arm head)
what is the overall pattern of lymph nodes and vessels in the head?
- superficial lymph vessels drain to superficial cervical nodes, which then drain to deep cervical nodes which drain into either right lymphatic duct or thoracic duct
what are the 5 groups of superficial lymph nodes in the head?
- occipital nodes (near occipital artery)
- mastoid nodes, including posterior auricular nodes (near auricular artery)
- parotid and/or preauricular nodes (near superficial temporal artery)
- submandibular nodes (near facial artery/ angle of jaw)
- submental nodes (near facial artery/chin)
what are the deep lymph nodes of the head and neck?
- jugulodigastric node ( just under ear behind jaw), receives lymph from tonsils and tonsillar beds
- jugulo-omohyoid node (just above omohyoid muscle and next to jugular vein) receives lymph from the tongue
- all other lymph drains into chain of deep cervical nodes in the neck, associated with the internal jugular vein and carotid sheath beneath the sternocleidomastoid
what are the deep lymph nodes of the head and neck?
- jugulodigastric node ( just under ear behind jaw), receives lymph from tonsils and tonsillar beds
- jugulo-omohyoid node (just above omohyoid muscle and next to jugular vein) receives lymph from the tongue
- all other lymph drains into chain of deep cervical nodes in the neck, associated with the internal jugular vein and carotid sheath beneath the sternocleidomastoid
what are the nervous structures (from superficial to deep) in the neck?
- cervical plexus, vagus nerve, other cranial nerves, sympathetic trunks, spinal cord
what is the cervical plexus?
- nerve system formed by the anterior rami of cervical nerves C1-4
- forms muscular/ deep branches and cutaneous/superficial branches
give some examples of the muscular/deep branches of the cervical plexus
- phrenic nerve, from anterior rami of C3-5
- ansa cervicalis (C1-3)
-C1 motor to thyrohyoid and geniohyoid muscles
what is the ansa cervicalis?
- neural loop in the neck formed from superior root from C1 and and inferior root from C2,3
- innervates infrahyoid muscles
what are the cutaneous/superficial branches of the cervical plexus?
- lesser optical nerve (C2) = skin of neck and scalp
- great auricular nerve (C2,3) = skin of ear and mastoid
- transverse cervical nerve (C2,3) = skin of lateral and anterior neck
- supraclavicular nerve (C3,4) = skin over clavicle and shoulder
how can you locate the cervical plexus branches?
- in posterior neck triangle, follow the sternocleidomastoid posterior border
what is a?
lesser occipital nerve
what is b?
greater auricular nerve
what is c?
transverse cervical nerve
what is d?
supraclavicular nerve
what is the pathway accessory(XI) nerve?
- accessory nerve has a spinal and cranial portion
- enters skull via foramen magnum (into cranial portion)
- travels with the vagus nerve through the jugular foramen to the pharyngeal plexus and laryngeal nerves
- the spinal portion reaches the sternocleidomastoid and trapezius
what is the pathway of the vagus (X) nerve?
- travels from medulla and leaves skull via the jugular foramen
- travels with accessory nerve to pharyngeal plexus and laryngeal nerves
- then ravels in carotid sheath to he thorax
describe the pathway of the glossopharyngeal (IX) nerve
- leaves the skull via the jugular foramen, crosses over the internal carotid but below the external carotid
describe the pathway of the hypoglossal (XII) nerve
- follows the stylopharyngeal muscle, crossing underneath the accessory and over the vagus nerve in the neck to reach the back of the tongue
what is the sympathetic trunk in the neck?
- located alongside the carotid sheaths anterior to the transverse processes of the cervical vertebrae
- then goes into sympathetic trunk of thorax
- collection of sympathetic nerves
where are the 3 ganglion of the sympathetic trunk in the neck?
- superior/upper ganglion = C1-4
- middle ganglion = C5-6
- inferior/lower/thoraco-cervical/stellate ganglion = C7-T1
