Compartments of the neck; Lecture 1 Flashcards
How many compartments in the neck and what are they
3; posterior, anterior, two posterior triangles
anterior compartment is divided into two what
anterior triangles
the anterior triangles are located where
superficially
below the anterior triangles are what structures
deep viscera- larynx/trachea and pharynx; vertical neurovascular bundle
what is the key landmark for dividing the neck into two triangles
SCM
SCM innervation
CN XI; accessory nerve
SCM attachments
superiorly to mastoid process and inferiorly to the sternal head and clavicle
SCM action
unilateral contraction tilts the head toward the shoulder of the same side, rotating face to opposite side
bilateral contraction protracts the head forward
how many layers of deep cervical fascia in the neck
four- investing layer, pretracheal layer, prevertebral layer, carotid sheath
what is the investing layer of fascia
deep cervical fascia that surrounds the entire neck; roofs the posterior and anterior triangles
what is the pretracheal layer of fascia
deep cervical fascia that forms a sheath around the thyroid gland
what is the prevertebral layer of fascia
deep cervical fascia that surrounds the support compartment of the neck (vertebra and musculature)- forms the floor of the posterior triangle
what is the carotid sheath
condensation of all three layers form a sheath enclosing the vertical neurovascular bundle of the neck
what is in the carotid sheath
- common carotid a.
- internal jugular v.
- vagus n.
what is buccopharnygeal fascia
fascia that wraps around the back of the pharynx, thickened part of the pretracheal
what is the retro-pharnygeal space and why is it clinically relevant
pathway between the prevertebral fascia and buccopharyngeal fascia; can allow for the spread of infection from the oral cavity down into the thorax
what veins are considered in superficial venous drainage of the face and neck
- superficial temporal v.
- maxillary v.
- retromandibular v.
- posterior auricular v.
- communicating v.
- facial v.
- external jugular v.
- anterior jugular v.
- jugular arch
which vein of the superficial veins of the face and neck is the largest
facial vein
Root levels of the cervical plexus
C1-4
the cervical plexus supplies sensory innervation where
to the neck and upper thorax regions
what nerves are in the cervical plexus
- lesser occipital n.
- transverse cutaneous n. of the neck
- great auricular n.
- supraclavicular n.
where can a cervical block be administered
at Erb’s point, which is approximately 1/2 up the posterior border of SCM
the nerves of the cervical plexus are what kind of rami
ventral rami
what are the root levels for each nerve of the cervical plexus
- lesser occipital- C2
- great auricular- C2/3
- transverse cervical- C2/3
- supraclavicular- C3/4
if the cervical plexus is ventral rami that supplies sensory innervation to face and neck, what supplies sensory innervation to back of head and down into back?
(know diagram in notes)
- dorsal ramus of C2 (greater occipital)
- dorsal rami C3-5
boundaries of the anterior triangle
- inferior border of mandible
- anterior border of SCM
- midline of neck
what is the digastric (submandibular) triangle
-contains the submandibular gland, facial a., lymph nodes, and mylohyoid muscle as the floor
what is the submental triangle
-located below the submental foramina; contains the submental lymph nodes and mylohyoid muscle as the floor
what is the carotid triangle
contains the common carotid a., internal jugular v., vagus n. (CN x), and hypoglossal n (CN XII)
what is the muscular triangle
contains the infrahyoid muscles forming the floor and viscera beneath the floor
what is the viscera beneath the floor of the muscular triangle
- thyroid
- larynx
- trachea
- esophagus
How many pairs of muscles are there that attaches to or is related to the hyoid bone
four pairs
what are the suprahyoid muscles
- digastric muscle
- stylohyoid
- mylohyoid
- geniohyoid
the digastric muscle has two bellies, what are the names
-anterior belly and posterior belly
what innervates the anterior belly of the digastric muscle
V3- trigeminal CN V Division 3
what innervates the posterior belly of the digastric muscle
CN VII- facial n.
what innervates the stylohyoid muscle
CN VII- facial n.
what innervates the mylohyoid muscle
V3
what innervates the geniohyoid
C1 via CN XII
what does C1 via CN XII mean
C1 motor branch hitches a ride on CN XII (hypoglossal n.) to get to the muscle
What are the two groups of infrahyoid muscles
superficial and deep
what muscles are in the superficial group of infrahyoid muscles
- sternohyoid
- superior belly of omohyoid
what are the muscles of the deep group of the infrahyoid muscles
- sternothyroid
- thyrohyoid
what innervates these 3 muscles: sternohyoid, omohyoid, sternothyroid
ansa cervicalis
what innervates the thyrohyoid
C1 via CN XII
Explain the action of the infrahyoid muscles with the suprahyoid muscles (its a combined action)
when the infrahyoid muscles contract, they depress and stabilize the hyoid bone so that the contraction of the suprahyoids allows them to function as accessory depressors of the mandible
What is a second action of the suprahyoid muscles
when they contract, the hyoid bone is raised and pulls the larnyx up by the thyrohyoid membrane during swallowing
the ventral rami of C1-4 are involved in a plexus that provides what kind of innervation
sensory innervation to the skin in the region of the neck and mote innervation to all the infrahyoid muscles as well as one suprahyoid muscle
how does the common carotid a. terminate
by bifurcating into the internal and external carotid aa. at the level of the superior border of the thyroid cartilage of the larynx
the internal carotid a. exhibits an initial swelling called what
the carotid sinus
what is the carotid sinus
a baroreceptor that regulates the blood pressure of the cerebral aa.
the internal carotid has no branches until it emerges in the ___ ___
cranial cavity
what is the carotid body
a small mass of tissue located at the bifurcation and lies in close relation to the carotid sinus
what does the carotid body do
it is a chemoreceptor that responds to the carbon dioxide level of the blood causing an increase in the respiratory centers of the brain if the levels get too high
innervation of the carotid body
the pharyngeal branch of the vagus n.
how many branches arise from the anterior and posterior aspects of the external carotid a.?
6
the first branch of the external carotid a. is named what and what does it supply
it is anterior and named the superior thyroid a.- it supplies the superior aspect of each lobe of the thyroid gland, it also gives rise to the superior laryngeal a. that supplies the larynx
what is the second branch of the external carotid a. and what does it supply
it is a posterior and is named the ascending pharyngeal a. and it supplies the pharynx and prevertebral mm.
what is the third branch of the external carotid a. and what does it supply
it is an anterior branch that is named the lingual a.- it supplies the muscles of the tongue
where does the lingual a. pass?
it passes deep to the hyoglossus m. and becomes the deep lingual a.
what is the fourth branch of the external carotid a. and what does it supply
it is an anterior branch and is named the facial a.- it hooks around the inferior border of the mandible to ascend on the face
what is the fifth branch of the external carotid a. and what does it supply
it is a posterior branch and is named the occipital a.- supplies the posterior scalp
what is the sixth branch of the external carotid a. and what does it supply
it is posterior and is named the posterior auricular a. and it supplies the adjacent parotid gland and scalp
what does the internal jugular vein drain
the brain, face and neck
where is the internal jugular vein formed
jugular foramen at the base of the cranial cavity
what is the major parasympathetic supply to thoracic and abdominal viscera as far along as the mid-transverse colon
vagus n.
what other supply does the vagus nerve provide
motor and sensory
what are the major branches off the vagus nerve in the neck
-superior laryngeal and right recurrent laryngeal nn.- both innervate the larynx
what are other major nerves in the same general region as the vagus n.
-accessory n. (CN XI)
-hypoglossal n. (CN XII)
-sympathetic trunk
-
pharyngeal plexus of nerves supplies what
pharynx
what nerves form the pharyngeal plexus
- pharyngeal branches of the vagus n.
- fibers of the cranial division of the accessory n. found within the vagus n.
- would be called CN XI via X collectively
- glossopharnygeal n. (CN IX) (sensory fibers)
- post-ganglionic sympathetic fibers from the superior cervical ganglion
- motor fibers derived from the cranial root of the accessory nerve (CN XI) and are distributed by branches of the vagus n.
what parts of the carotid triangle are used in surgical approaches
carotid arterial system, internal jugular vein, CN X, XII, and the cervical sympathetic trunk
the carotid sinus responds to increase in blood pressure by doing what
telling the heart to slow down via parasympathetic output by the vagus n.
pressure on the carotid sinus can cause what
fainting and in hypersensitive individuals, cessation of the heart beat
A carotid pulse can be detected in what artery
external carotid artery
what innervates the carotid body
branches of CN IX, X, and sympathetic fibers
how does the carotid body respond to an increase in carbon dioxide or decrease in oxygen
increase respiration rate
why is the muscular triangle clinically significant
used in surgical approaches to the thyroid and parathyroid glands, as well as exposure to the esophagus and trachea
all lymphatic vessels from the head and neck drain into the ____ ___ ___
deep cervical lymph nodes
during a radical resection of the neck region, what must be removed?
the deep cervical lymph nodes and external and internal jugular vv. on one or both sides
