Neck Flashcards
What is the superior limit of the neck?
Mandible and base of skull
What is the inferior limit of the neck?
Thoracic inlet
Where is the apex of the lungs found?
About 1 inch above medial third of the clavicle
Which anatomical structure divides the neck into anterior and posterior triangles?
sternocleidomastoid (sternum, cleido/clavicle, mastoid)
What is the proximal attachment of the sternocleidomastoid?
Mastoid process
What is the distal attachment of the sternocleidomastoid?
Sternum and clavicle
What are the boundaries for the anterior triangle of the neck?
Sternocleidomastoid, midline (line from chin to manubrium), lower border of mandible
What are the borders of the posterior triangle of the neck?
Sternocleidomastoid, trapezius muscle, middle third of clavicle
Function of trapezius muscle
raises shoulders
Function of sternocleidomastoid
Unilateral contraction rotates head to opposite side. Bilateral contraction flexes neck toward chest
What are the five groups the contents of the anterior triangles can be divided into?
Muscles, nerves, blood vessels, glands, skeletal elements and viscera
What are the muscles of the anterior triangle?
Mylohyoid, anterior belly of digastric, infrahyoid (strap) muscles
What is the mylohyoid?
The muscles that forms the floor of the mouth and attaches to each side of the mandible
Which muscle of the anterior triangle functions to open the mouth?
Anterior belly of digastric
What are the infrahyoid muscles?
Very thin muscles that hold the hyoid bone in place
Which muscles make up the infrahyoid muscles?
Sternohyoid, sternothyroid, thyrohyoid, omohyoid muscles
What are the skeletal elements of the anterior triangle?
thyroid cartilage, cricoid cartilage, hyoid bone, trachea
Which is the largest of the laryngeal cartilages?
Thyroid cartilage
Where is the cricoid cartilage located?
Inferior to the thyroid cartilage, superior to the trachea
Which is the only laryngeal cartilage to form a complete circle?
Cricoid cartilage
What forms the Adam’s apple?
The laryngeal prominence of the thyroid cartilage
What structure connects the thyroid and cricoid cartilage?
Cricothyroid membrane
Name of the procedure that pierces the cricothyroid membrane to establish an airway in emergencies
Cricothyrotomy
Which glands are present in the anterior triangle of the neck?
Thyroid gland, parathyroid glands, submandibular glands
What type of gland is the thyroid gland?
endocrine
What envelops the thyroid gland?
pre-tracheal fascia
What is the blood supply of the thyroid gland?
superior and inferior thyroid arteries
Where does the superior thyroid artery branch from?
external carotid artery
Where does the inferior thyroid artery branch from?
Thyrocervical trunk
Structure of the thyroid gland
Butterfly shaped made up of a right and left lobe divided by an isthmus. Pyramidal lobe extends superiorly from the isthmus.
Where does the thyroid gland originate from?
Foramen caecum of tongue
What structure can be present extending from the pyramidal lobe to the hyoid bone?
Levator glandulae thyroidae
What is the levator glandulae thyroidae?
Fibrous tissue that can be present as a remnant of the movement of the thyroid gland from the floor of the mouth to the root of the neck. Can be a site of thyroid cancer.
How many parathyroid glands are there?
4 - 2 inferior and 2 superior sets
What percentage of the population have more than 4 parathyroid glands?
5%
Function of parathyroid glands
Release parathyroid hormone which increases Ca levels (needed for muscle contraction)
What can happen if there is a change in Ca balance?
Tetany (involuntary muscle contraction)
What must be checked during a thyroidectomy?
That parathyroid glands remain in the neck (prevents tetany)
What type of secretion is from the parotid gland?
serous
What type of secretion is from the submandibular gland?
Mixed (seromucous)
What type of secretion is from the sublingual gland?
Mucous
Which nerves are found in the anterior triangle of the neck?
Vagus (CN X), phrenic, hypoglossal (CN XII) nerves
Which nerve supplies the muscles of the pharynx and larynx?
Vagus nerve (CN X)
What are the roots of the phrenic nerve?
C3, C4, C5 (keeps the diaphragm alive)
Location of hypoglossal nerve (CN XII)
Below level of the tongue (hypo - low)
Function of the hypoglossal nerve (CN XII)
motor - innervates muscles of the tongue
Function of phrenic nerve
innervates diaphragm
Which disease involved surgically dividing the phrenic nerve as treatment in the 1950s?
For tuberculosis (no longer done - paralyses half the diaphragm - there are 2 phrenic nerves)
What blood vessels are found in the anterior triangle?
Common carotid artery (bifurcates into internal and external), jugular veins (anterior, internal and external)
Which vein in the anterior neck triangle drains the brain?
Internal jugular vein (can cause air in brain if air enters)
How can the contents of the posterior triangle of the neck be divided?
nerves, muscles, vessels, lymph nodes
Which nerves are found in the posterior triangle?
Accessory nerve (CN XI), parts of the brachial plexus, cutaneous cervical nerves
Function of accessory nerve (CN XI)
motor - supplies sternocleidomastoid and trapezius
Function of the brachial plexus
motor and sensory - supplies all muscles and innervation of upper limbs
Where does the brachial plexus originate from?
C5, C6, C7, C8, T1
How can the brachial plexus be torn?
Twists/injuries/trauma - e.g. motorbike accidents, babies during birth
Structure/shape of lymph nodes
small oval bean shaped structures
Function of lymph nodes
Filter lymph, return to larger veins, offer defence against spread of infection
Name the main vein lymph is returned to
Left subclavian vein
Why is it bad if cancer enters lymph nodes or blood vessels?
Cancer will metastasise (spread from one part of the body to another)
Where are lymph nodes in the head and neck located?
Everywhere - pre/post auricular (occipital nodes), around internal jugular vein
Potential causes of swellings in neck?
cysts, dental abscess, cancer, swelling from trauma, goitre (enlarged thyroid gland)
