Anterior Triangle of the Neck Flashcards
Which neck triangle (anterior or posterior) does the carotid triangle lie within? What important structures are contained in the carotid triangle?
It is within the anterior triangle of the neck. The carotid arteries and internal jugular vein are found in the carotid triangle.
What are the borders of the submental triangle? What two things are contained in this triangle?
The two anterior bellies of the digastric muscle and the superior edge of the hyoid bone. Submental lymph nodes and small veins are in it.
How many suprahyoid muscles are there? How many infrahyoid muscles are there?
4 suprahyoid, 4 infrahyoid
Name the suprahyoid and infrahyoid muscles.
Suprahyoid:
- Mylohyoid muscle
- Digastric (anterior and posterior bellies - DUAL INNERVATION!)
- Stylohyoid
- Geniohyoid
Infrahyoid:
- Thyrohyoid
- Sternothyroid
- Sternohyoid
- Omohyoid (superior and inferior bellies)
Which suprahyoid muscle has dual innervation? Which nerves?
Digastric:
- Anterior belly is supplied by nerve to mylohyoid (branch of CN V3)
- Posterior belly is supplied by branches of the facial nerve (CN VII)
What are the actions of each of the four infrahyoid muscles?
Omohyoid depresses the hyoid bone.
Thyrohyoid brings together the hyoid bone and thyroid cartilage.
Sternohyoid depresses the hyoid bone.
Sternothyroid depresses the thyroid cartilage.
What nerves supply the infrahyoid muscles?
The ansa cervicalis + C1 via hypoglossal (the geniohyoid and thyrohyoid muscles)
Which nerve roots make up the ansa cervicalis?
C1, C2, C3
Describe the branches of the ansa cervicalis, including the muscles that each innervate.
Some C1 fibers run with CN XII in the hypoglossal canal and exit to supply the geniohyoid and thyrohyoid.
The superior root consists of C1 and C2 fibers and supply the sternohyoid and omohyoid superior belly.
The inferior root consists of C2 and C3 fibers and supply the sternothyroid and omohyoid inferior belly.
Which nerve runs between the internal jugular vein and common carotid artery?
The vagus nerve
Where do the common carotid arteries arise from? At what spinal level do they split into the internal and external carotid arteries?
The right common carotid is a branch of the right brachiocephalic artery. The left common carotid comes off the aortic arch. They split into the internal and external carotid arteries at C4/C5 - the same level as the top of the thyroid cartilage.
What nerve is at risk when ligating a thyroid tumor? Where does this nerve lie in relation to the inferior thyroid artery?
The recurrent laryngeal nerve is at risk. It lies immediately posterior to the inferior thyroid artery behind the thyroid gland.
What nerve runs down the anterior aspect of the anterior scalene muscle?
Phrenic nerve
Describe the branches of the internal carotid artery in the neck.
This is a trick! It has none, it goes up to supply the brain.
Name the branches of the external carotid artery as they come off from inferior to superior.
SALFOPSMax
superior thyroid ascending pharyngeal lingual facial occipital posterior auricular superficial temporal maxillary
The external carotid supplies everything outside the dura mater except the _______ _______. This area is supplied by the _________ artery, a branch of the ________ artery.
the anterior forehead is supplied by the supraorbital artery, a branch of the opthalmic artery (from the internal carotid)
Through what does the internal carotid artery enter the base of the skull?
The carotid canal.
Through what do the vertebral arteries enter the skull?
Through the foramen magnum.
What structures do the circle of Willis surround?
The pituitary gland and optic chiasm.
If a vertebral artery were occluded near where it forms the basilar artery, where would the posterior cerebral artery get blood from?
From the internal carotid artery –> posterior communicating artery –> posterior cerebral artery
What is a transient ischemic attack? What are five symptoms?
Ischemia of brain tissue without infarction.
- Hemiparesis - decreased limb strength on the same side of the stroke for several minutes.
- Paresthesia - tingling and numbness over 1/2 the body.
- Transient monocular blindness.
- Aphasia - loss of speech.
- Mental confusion.
Is the carotid bifurcation a common site of atherosclerotic stenosis? What happens if an emboli breaks off?
Yeah. If it breaks off –> stroke.
What is the carotid sinus? What are carotid bodies? What nerve is involved in afferent signaling to the brain?
Carotid sinus measures stretch, carotid bodies are chemoreceptors (PO2, PCO2). The carotid sinus nerve from CN IX - glossopharyngeal transmits visceral sensory info to the hypothalamus.
What does massaging the carotid artery do?
Stimulates the carotid sinus –> afferent signal up the glossopharyngeal nerve (CN IX) –> hypothalamus –> vagus nerve to heart slows the heart rate.
Where are the sympathetic chains located in relation to the carotid sheath?
Posterior to the carotid sheath
Where do pre-ganglionic sympathetic fibers synapse with cell bodies of post-ganglionic sympathetic neurons?
In the sympathetic ganglia (trunk)
What is Virchow’s node and what can its enlargement possibly indicate?
Its the left supraclavicular node, enlarges as a result of gastric cancers.
What is the largest endocrine gland and what does it make?
Thyroid, makes T3, T4, calcitonin.
At what spinal level is the cricoid cartilage found? What about the isthmus of the thyroid?
Cricoid cartilage is at C6, isthmus of the thyroid is at C7
What is the name of the place where the thyroid begins its development? How does a thyroglossal duct cyst form?
The thyroid starts at the foramen cecum of the tongue and descends inferiorly along the the thyroglossal duct to its usual position. If the duct remains patent, a cyst can form.
What is the treatment for a thyroglossal duct cyst?
Sistrunk Procedure – surgical resection of the duct to base of tongue including the body of hyoid bone to ensure complete removal of the duct.
What is a goiter? Name two complications of big ones.
Benign hypertrophy of the thyroid gland, usually from iodine deficiency (TRH levels are chronically high due to low circulating thyroid hormones). Big ones can compress or deviate the trachea or esophagus.
How many parathyroid glands are there (usually)? What do they to?
There are usually 4, 2 superior and 2 inferior. They make PTH, which increases blood Ca2+ levels.
What is the difference between a tracheostomy and a tracheotomy?
Both are surgical incision into the trachea. A tracheostomy is permanent or semi-permanent.
Where is a tracheostomy performed?
Between tracheal rings, usually between the 2nd and 3rd.
What structures are at risk during a tracheostomy?
The brachiocephalic artery and the left brachiocephalic vein.
Where is a cricothyrotomy performed? In what situations is it performed?
Through the cricothyroid membrane (the thing between the cricoid cartilage and thyroid cartilage). Performed in emergency situations; considered safer than a tracheotomy/tracheostomy.
What part of the brachial plexus (roots, cords, trunks, etc.) run between the scalene muscles?
The roots!
