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