10/27 Anatomy of the Neck! Flashcards
where do the neck muscles derive from?
they derive from the branchial arches and somites
What are the somite like structures in the head of an embryo?
the pre-otic and post-otic somites that are just above and below the otic plate that makes your ear.
where do the muscles bones, vessels etc. of the head come form?
they come form the pre-otic somites and the post-otic somites and largly from the Branchial arches.
why are there both branchial and somatic muscles found in the neck
head muscles migrate down and anchor and give support to the head on the neck (“orange on a tooth pick”)
what are the posterior or hind arch?
this is tissue that straddles the somite world and the branchial world of the embryo. they are the spinal accesory nerve etc.
What are the muscles of the neck in summary at a cross-section of the C7 level from the anterior to the posterior?
platysma (anterior); Sterno-clodal-mastoid; infrahyoid mm.; longus coli (anterior the spine); A. Scalene; M. Scalene; P. Scalene; Lev Scap. M. Erector spina and transv sp. mm.; Trapezius.
What are the non-muslce structures to ID in a transverse of the neck at C7 (summary from ant. to post.)
Thyroid gland; Trachea; Esophagus; IJV, CA, Vegas Nerve; C7 vertebra.
what are the brachial arch muscles of the nech?
The 2nd branchial arch and the posterior branchial arch give rise to the exterior muscles of the neck: Platysma; SCM; Trapezius.
what are the somite muscles of the neck?
the Epaxial (Erector spina; transv. spinalis) muscles and the Hypaxial (Infrahyoid, longus coli, Anterior, middle, and posterior scalene, lev. scap.) muscles make up the inside muscles of the neck:
what are the epaxial muscles
the deep and back muscles: erector spinae and transv spinalis mm or the para spinal muscles
what are the hypaxial muscles of the somite muscles of the neck?
supracostal layer (Lev. Scap.); external layer (Post scalene); intermediate layer(middle scalene); internal layer (anterior scalene); sub-vertebral layer (Longus coli); ventral strap layer (infrahyoid);
where is the neurovascular plane?
between the intermediate and the internal layer of the lateral wall muscles. or between the anterior and middle scalene
What is the 2nd branchial arch muscle in the neck?
the platesma
what is the posterior branchial arch muscle of the neck?
the Sternal cloidal mastoid and the trapezius.
what type of nerve innervates the posterior branchial arch muscles?
cranial nerves!
where does the SCM muscle attach?
Sternum, clavical and mastoid process of the temporal bone
purposes of the trapezius muscle
elevates, depresses and adducs the scapula and rotates
what innervates the SCM, and Trapezius?
cranial nerve eleven or the spinal accessory nerve.
why is the cervical fascia important for us?
it circumscribes and seprates muscle groups, blood vessels and nerves
why is the cervical fascia important for clinicals
surgical orientation and in directing the course of infection.
cerivcal fascia layers:
Subcutaneous tissue (superficial cervical fascia); deep cervical fascia
what are the subdivisions of the deep cervical fascia:
Trapezius and SCM; Somatic body wall; Visceral Comartment
what is the subcutaneous tissue/superficial cervical fascia in essence?
the hypodermus of the neck or the “campers fasca”
what muscle is in the superficial fascia
the platisma
Describe the first layer of the Deep cervical fascia
The Trapezius and SCM fascia enveloping muscles that arise from the posterior (caudal) branchia arch encircles the neck just below the subcutaneous tissue and envelops the SCM and trapezius.
How is the fascia of the neck “body wall” muscles similar to what we see in the abdomen?
We have an External investing fascia and an internal investing fascia!
Where is the somatic body wall external investing fascia in the neck?
it is found around the outside of the infrahyoid and all the way around the neck and outside of the epaxial muscles in the back.
where is the somatic body wall internal investing fascia?
it is behind the infrahyoid muscles and around the trachia/esophagus and infront of the anterior scalene/ longus coli and spine. just encircling all of the non-muslce stuff in the middle.
where is the visceral compartment fascia?
it is the fascia that inveloping the viscera in the cervical region (continuous superiorly with branchial arches 4 and 6 and inferiorly with the gut tube. (surrounds the thyroid, trachia, esophagus etc. and provides a route from the head to the gut tube!
What is the anatomic divisions of the deep cervical fascia?
Investing fascia; pretracheal fascia; prevertebral fascia; carotid sheath.
where is the investing fascia
the superficial layer of the deep cervical fascia or the fascia of the trapezius and the SCM goes around the SCM and the trapezius and make a belt around the neck.
where is the pretracheal fascia
it is around the viscera or the trachia and the thyroid gland. Completely encircles it!
when is it a serousa and when is it adventitia?
it is serosa when it is surrounded by a celomic sac tissue!
where is the prevertebral fascia?
surrounds all of the muscles of the body wall except the ventral strap. It surrounds the 4 layer body wall and epaxial muscles around the spine.
what are the two plexus
cervical plexus (C1-C4) and the Brachial plaexus (C5-T1)
where are the origin of the plexus in the neck?
they come out between the A. Scalene and the M. scalene (between the internal dn innermediate layer muscles
what does the prevertebral fascia form towards the arms?
they will form the axillary sheath
Where is the carotid sheath
it is around the IJV, the carotid arteries and the vagus nerves (CN X) and is really made by the other deep fascia around it (
How do you find the IJV on a patient to measure the jugular venus pulse?
you find the two bellies of the SCM at the clavical and the IJV is right between them.
The name given to the pretracheal fascia behind the esophagus
the buccopharyngeal fascia
the space that can fill with puss or tumor behind the buccopharyngeal fascia
retropharyngeal space this is right between the pretracheal fascia and the prevertebral fascia and can be a canduit of inflamation!
why is the retropharyngeal space important
it means that “soar throat” can spread to the regropharnygeal space and down the “elevator shaft” to the medai stinum
what about the fascia around the infrahyoid muscles?
they are a subset of the investing fascia of the SCM…or its own fascia called the middle layer of deep cervical fasciia…or part of the visceral fascia!
what is the origin of a muscle
the stabalized origin of a muscle (doesn’t move)
what is the insertion of the muscle?
it is the bony connection that moves.
what is the innervation of the platysma muscle?
innervated by cranial nerve number 7 since it is a 2nd branchial arch muscle.
What is the innervation of the SCM
Cranial nerve number 11
what is the action of the SCM
rotate the head to the opposite side. and help to elevate the rib cage and flexing the neck.
what is the action of the platysma?
to tense the skin of the neck
what is the purpose and innervation of the levator scapula muscle?
innervated by dorsal scapula nerve and helps elevate the shoulders.
what is the purpose of the scalene muscles?
to elevate the rib cage like a pump handle!
what is the innervation of the scalene muscles?
the cervical plexis.
the muscles of the neck along the anterior of the spine…
longis capitus and longus coli, innervated by cervical plexis.
what are the ventral strap muscles?
the omohyroid (shoulder to hyroid); sternal hyroid; sternalthyroid; thyrohyoid muscle.
What is the innervation of the infra-hyoid muscles?
motor neurons of the cervical plexus.
what are the purposes of the ventral stap muscles of the neck
speaking and tounge movement, and inervated by the cervical plexis
one more time…where are the nerves and the axillary artery found in the neck?
coursing out between the ant. scal. and the mid. scal.
Describe the cervical plexus:
PICTURE HERE!!!!
Describe the general nervous system layout and plexes
PICTURE HERE!!!!
Explain a cross section of the spinal chord!
PICTURE HERE!!!!
what does the greater auricular nerve innervate?
the skin infront of the ear (by the ear)
what is the cervical plexus
a plexus of the ventral rami from the C1-C4 spinal nerve levels (these nerves are mixed)
what does the cervical plexus provide sensory innervation to?
the skin of the neck, the scalp and infront of the ear.
what does the cervical plexus provide motor innervation to?
the cervical body wall muscles; scalenes, infrahyoid etc. and the diaphram!
what does the C1 level ventral ramus give rise to?
the peak of the ansa cervicallis (two branches in the picture)
what does the C2 ventral ramus give rise to?
the ansa cervicalis, the lesser occipital n; the Great auricular nerve; and contribute to the transverse cervical nerve! (four branches in the picture)
what does the C3 ventral ramus give rise to?
the Great auricular nerve (w/C2); the transverse cervical nerve (w/C2), and the supraclavicular nerve (w/C4); and the Phrenic nerve (w/C4,C5). (Four branches in the picture)
what does the C4 level ventral rami give rise to?
The Supraclavicular nerve (W/C3); the Phrenic nerve (W/C3, C5). (two branches in the picture)
What does the C5 ventral Rami give rise to?
the Phrenic nerve (w/C3,C4) (one branch in the picture)
what does the Ansi cervicallis give rise to?
Start at C1 loop back to C3, and C2, and then C2 sends off a new branch to C1 to complete the loop. the loop runs along the hypoglossal (CN XII), and gives rise to 5 branches to the infrahyoid muscles.
what does the lesser occipital n come from and innervate
from C2; skin behind the scalp
what does the Great auricular nerve come from and innervate
From C2, C3 the skin around the ear.
What does the transverse cervical nerve come from and innervate?
from C2,C3; and skin accross the front of the neck
What does the Supraclavicular nerve come from and innervate?
from C3,C4. The skin just infront of the clavical.
What does the Phrenic nerve come from and innervate?
from C3,C4,C5: motor to diaphram and sensory to the mediastinal pariatal plura, pariatal paracardiam and daiaphragamatic pariatal paratanium.
What does the ansa cervicallis provide and come from?
from C1 with contributions from C3 and C2 at the bottom, and provide motor control to the infrahyoid muscles.
what provides motor inervation to the infrahyroid muscles.
the Ansa cervicalis
what type of sensory are the cutaneious nerves? (the nerves from the upper left of the cervical plexus drawing?
sensory nerves.
what type of innervation is the Ansa cervicalis?
motor nerves
What type of innervation is the phrenic nerve?
mixed motor and sensory.
what is the dorsal ramus from C2?
the greater occipital nerve
Describe the sensory innervation from the back of the head through the neck, down to the cervical.
Back of the head:Greater Occipital (dorsal C2); Behind the ear: lesser occipital(C2); Below the ear: Great auricular(C2-C3); Midline of the neck: Transverse cervical (C2-C3); front of cervical: Supraclavicular (C3-C4)
where is the ansa cervicalis?
it is in the carotid sheath fascia (around the JV, CNX, C)
Where does the cervical plexus exit the spinal cord to come outside the scalene?
between the anterior and the middle scalene.
What are the Arteries found in the neck?
common Carotid that splits to the internal carotid artery and the external carotid artery.
what does the internal carotid artery supply?
the front and side of the brain, orbit, scalp
What does the external carotid artery supply?
the face, the neck
what drains blood through the neck?
the Internal jugular vein (IJV)
What are the main nerves in the neck?
the cervical plexus; the glossopharyngeal nerve (CN IX); Vagus nerve (CN X); Sympathetic trunk
what supplies the posterior brain?
the vetebral arteries.
Where does the internal carotid artery enter the skull
the carotid canal
where are the baral receptors in the carotid artery?
at the carotid sinus that has the baral receptors. at the base of the internal carotid artery.
what does the baral receptors measure?
it measures the deviation from the individual normal blood preasure
what measures carbon dioxcide / oxygen in the blood and therefore the pH of the blood.
the carotid body at the biforcation of the common carotid artery.
What innervates the carotid sinus?
CN 9 glosialpharingial nerve
what innervates the carotid body
CN9 (GF) and CN10
what does the external carotid artery supply?
thyroid, larnx, tounge, face, pharnxy, posterior scalp and ear.
what drains the brain and the thyroid gland?
the internal jugular vein.
What is interesting about the valves of the jugular vein?
the right IJV lacks valves; the Left IJV has 1 valve! So you can see the pressure of the Right side of the heart by measuring the hight of the right IJV pulse
what drains blood from the face
the external jugular vein
provides visceral sensory innervation for the carotid sinus and carotid body
glossopharyngeal n. (CN IX) it is a visceral sensory nerve CNX (vegas) for the carotid body as well.
what forms the superior cervical gangleon?
C1,C2,C3,C4
at the Superior cervical gangleon.
all sympathetics that go to the head will synapse
how many sympathetic cervical ganglia are there?
not eight…only three…the top three or four are fused, 5/6 fuse. 7/8 fuse.
Describe the innervation of the sympathetics of the eye, sweat glands of face etc. and blood vessels in the head/neck.
sympathetic motor neurons arise from the T1 lateral horn primarily send out pre-synaptic neuron through the white matter communicon, up the sympathetic chain to synapse at the superior sypathetic gangleon, then out the gray matter comunicon and onto the ICA, and like christmas lights it spirals its way up and follow the arteries all over!
what uses the white matter communicon
the presynaptic sympathetic nerve (traveling up and down the chain or right into a gangleon to synapse), and the incoming visceral sensory (these guys are mylanated!)
what uses the gray matter communicon
The post synaptic sympathetic nerve as it exits the gangleon to go to the target!
