CVR: Anatomy of the Head and Neck Flashcards
What is the platysma?
A very thin subcutaneous and superficial muscle just under the skin in the neck.
What bone helps keep the pharynx open and provides an attachment point for several muscles including the tongue? Where is this bone situated?
Hyoid bone.
Anterior in the upper neck, inferior to the mandible.
Describe the basic structure of the layrnx.
A ‘skeleton’ of small cartilages connected by membranes and small joints.
Protects the airway, and can be moved by muscles to move the vocal cords.
What separates the anterior and posterior triangles of the neck?
The sternocleidomastoid muscle (SCM).
What movements are controlled by the sternocleidomastoid muscle?
Unilateral (using just the left or right SCM); turning the head.
Bilateral (using both left and right SCM together); nodding the head.
What nerve innervates the sternocleidomastoid and trapezium muscles?
Cranial nerve XI; the accessory nerve.
What are the anterior, posterior, and superior borders of the anterior triangle?
Anteriorly; midline of the neck
Posteriorly; the anterior border of sternocleidomastoid muscle
Superiorly; the lower border of the mandible
Which triangle of the neck (anterior or posterior) contains the thyroid, parathyroid, and submandibular salivary glands?
The anterior triangle.
Name two groups of four paired muscles in the anterior triangle of the neck. How do they move the hyoid and larynx for speech and swallowing?
Suprahyoid muscles; raise hyoid bone and larynx during speech and swallowing.
Infrahyoid muscles; pull the hyoid and larynx down during speech and swallowing.
What muscle group forms the floor of the mouth and connects the hyoid to the skull?
The suprahyoid muscles.
The infrahyoid muscles connect the hyoid to what two other bones?
The sternum and the scapula.
What’s another name for the infrahyoid muscles?
The infrahyoid muscles are also known as the strap muscles.
Branches of which nerves would you find in the anterior triangle of the neck?
Branches of the facial nerve (CN VII), the glossopharyngeal nerve (CN IX), the vagus nerve (CN X), the accessory nerve (CN XI), and the hypoglossal nerve (CN XII).
The common carotid artery, branches of the external carotid artery, and the internal jugular vein, are all vessels in the anterior or posterior triangle of the neck?
Anterior triangle.
What are the anterior, posterior, inferior, and apex borders of the posterior triangle of the neck?
Anteriorly; the posterior border of the sternocleidomastoid
Posteriorly; the anterior border of trapezius
Inferiorly; the clavicle
Apex; formed by sternocleidomastoid and trapezius
What is the function of muscles in the posterior triangle of the neck?
To move the head.
In which triangle of the neck would you find the external jugular vein?
The posterior triangle.
Which nerves would you find in the posterior triangle of the neck?
The accessory nerve (CN XI)
The roots of the brachial plexus.
The phrenic nerve.
Where is the thyroid gland situated?
Each lobe is just lateral to the lower larynx and upper trachea, and is deep to the infrahyoid muscles.
What joins the two lobes of the thyroid together?
The isthmus.
What arteries supply the thyroid gland?
Superior thyroid arteries (branches of external carotid)
Inferior thyroid arteries (branches of thyrocervical trunks - which are branches of subclavian)
What veins drain the thyroid?
Superior, middle, and inferior thyroid veins.
What are the four parathyroid glands and where are they situated?
Right and left superior and inferior parathyroid glands.
Posterior to the thyroid.
What additional artery supplies the thyroid gland in <5-10% of the population?
Thyroid ima artery.
Does the internal or external carotid artery supply the brain? Does this artery supply anything else?
The internal carotid artery supplies the brain only.
The common carotid arteries bifurcate into…
Left and right internal and external carotid arteries.
What the name for the small swelling at the bifurcation of the common carotid artery?
The carotid sinus.
Why is the carotid sinus important for regulating blood pressure?
The carotid sinus contains baroreceptors, relaying visceral sensory information about blood pressure to the brainstem via the glossopharyngeal nerve.
Where is the internal carotid artery palpable?
Immediately lateral to the larynx.
Which jugular vein drains blood from the brain and part of the face? Where does the other jugular vein drain blood from?
The internal jugular vein.
The external jugular vein drains blood from the scalp and face.
What nerve is sandwiched between the common carotid and the internal jugular vein?
The vagus nerve (CN X).
Which nerve descends the neck immediately posterior to the sternocleidomastoid?
The accessory nerve (CN XI).
Which nerve provides motor innervation to the tongue?
The hypoglossal nerve.
What would you find inside the carotid sheath?
Common and internal carotid arteries, the internal jugular vein, the vagus nerve, sympathetic plexus.
What 4 structures make up the laryngeal “skeleton”?
Hyoid bone
Thyroid cartilage
Cricoid cartilage
Arytenoid cartilages x2
What sensory and motor functions does the superior laryngeal nerve have?
Sensory: internal larynx above the cords
Motor: cricothyroid muscle only
What sensory and motor functions does the recurrent laryngeal nerve have?
Sensory: internal larynx below the cords
Motor: intrinsic muscles other than cricothyroid (which is innervated by the superior laryngeal nerve)
Is the thyroid gland anterior or posterior to the thyroid cartilage?
Anterior
What nerve mediates the gag reflex?
Glossopharyngeal nerve (CN IX)
Do the internal and external jugular veins merge together?
No. There is no common jugular vein.
Internal drains into brachiocephalic.
External drains into subclavian.
How many cervical vertebrae are there?
7
What is the function of the sternocleidomastoid?
Nodding and shaking the head
Which triangle of the neck is the brachial plexus located in?
Posterior triangle of the neck.
What is the name of the muscles that form the walls of the pharynx?
Constrictors
Which nerve supplies the cricothyroid muscle?
External branch of superior laryngeal nerve
Which nerve carries visceral sensory information from the carotid sinus and body?
Glossopharyngeal (CN IX)
Which vein is formed by the Internal Jugular Vein and Subclavian Vein combining?
Brachiocephalic vein.
What are the two inner and outer layers of muscle in the walls of the pharynx?
Outer/external circular muscles.
Inner longitudinal muscles.
What are the three constrictor muscles of the pharynx?
Superior, middle, and inferior constrictors.
During swallowing, what pushes food from the oral cavity into the oropharynx?
The tongue
What stops food entering the nasopharynx during swallowing?
The soft palate.
What is the epiglottis and what is its key role?
One of the cartilages of the larynx. During swallowing, the epiglottis closes off the laryngeal inlet and prevents food/liquid entering the larynx.
Sensory and motor fibres from which nerves innervate the pharynx?
Sensory = glossopharyngeal nerve
Motor = vagus nerve
What tissue forms the tonsils?
Lymphoid tissue.
What are the four different tonsils?
Pharyngeal
Tubal
Palatine
Lingual
Which are visible in the oropharynx and are the structures laypeople refer to as “the tonsils”?
Palatine; these are the tonsils next to the pharyngeal wall in the oropharynx that laypeople call “the tonsils”.