Anterior Neck Flashcards
What are the 3 tonsils in the pharynx?
palatine tonsils, lingual tonsils, and pharyngeal tonsils
Where are palatine tonsils?
located on L and R sides of posterior throat, can see when one opens mouth
What are pharyngeal tonsils also called?
adenoids
What is the function of the thyroid?
regulates metabolism
What is the function of vocal folds?
produces sound
folds of tissue in larynx
What and where is the cricoid cartilage?
ring-shaped cartilage of larynx
found on top of 1st tracheal C-ring
What innervates the platysma?
facial nerve (CN VII)
What is the action of the platysma?
draws neck skin superiorly when teeth clenching
draws mouth corners inferiorly and widens when expressing fright/sadness
What is the origin (proximal attachment) and insertion (distal attachment) of the sternocleidomastoid muscle?
Origin =
- lateral half of superior nuchal line
- lateral surface of mastoid process
Insertion =
- sternal head = anterior surface of manubrium
- clavicular head = superior surface of medial third of clavicle
What innervates the sternocleidomastoid?
- spinal accessory (CN XI = motor)
- C2 and C3 spinal nerves
What is the action of sternocleidomastoid?
Unilateral =
- lateral flexion of neck
- rotates head superiorly to opposite side
Bilateral =
- extends neck at atlanto-occipital joints
- flexes cervical vertebra = chin touches manubrium
- thrusts head forward at head level = extends superior cervical vertebra while flexing inferior cervical vertebra
What are the 3 deep muscles of the anterior neck?
longus capitis
longus colli
rectus capitis lateralis
What innervates the longus capitis muscle?
anterior rami C1-C3 spinal nerves
What is the action of the longus capitis?
flexes head and neck anteriorly or laterally
What innervates the longus colli muscle?
anterior rami of C2-C6 spinal nerves
What is the action of the longus colli?
flexes neck anteriorly or laterally at C2-C7
What innervates the rectus capitis lateralis muscle?
branches from loop between C1 and C2 spinal nerves
What is the action of the rectus capitis lateralis muscle?
flexes head
helps stabilize head
What are the 4 suprahyoid muscles?
- digastric muscle (superior and inferior bellies)
- geniohyoid
- stylohyoid
- mylohyoid
What innervates the digastric muscles?
Anterior belly = trigeminal nerve (CN V3) –> mandibular nerve –> inferior alveolar nerve –> mylohyoid nerve
Posterior belly = facial nerve CN VII –> digastric branch
What is the action of digastric muscles?
- depresses mandible against resistance
- elevates and stabilizes hyoid bone during swallowing and speaking
What innervates the mylohyoid muscle?
trigeminal nerve 3 (CN V3) –> mandibular branch –> inferior alveolar nerve
What is the action of the mylohyoid?
- elevates hyoid
- elevates floor of mouth
- elevates tongue during swallowing and speaking
What innervates the geniohyoid muscle?
hypoglossal nerve CN XII –> C1 spinal nerve
What is the action of the geniohyoid muscle?
- elevates hyoid bone anterosuperiorly
- shortens floor of mouth
- widens pharynx
What innervates the stylohyoid muscle?
facial nerve (CN VIII) –> stylohyoid branch
What is the action of the stylohyoid muscle?
Elevate and Retract hyoid bone
What are the 4 infrahyoid muscles?
beneath hyoid bone
TOSS = thyrohyoid, omohyoid, sternohyoid, sternothyroid
What innervates the thyrohyoid muscle?
hypoglossal nerve (CN XII) –> C1 spinal nerve
What is the action of thyrohyoid?
Depresses hyoid bone
Elevates larynx
What innervates the omohyoid?
Ansa Cervicalis = C1 - C3 spinal nerves
What is the action of the omohyoid?
Depresses, Retracts, and Stabilizes hyoid bone
What innervates the sternohyoid muscle?
Ansa Cervicalis = C1 - C3 spinal nerves
What is the action of the sternohyoid?
Depresses hyoid bone after elevation during swallowing
What innervates the sternothyroid?
Ansa Cervicalis = C2 - C3 spinal nerves
What is the action of the sternothyroid?
Depresses hyoid bone and larynx
What is the cervical plexus?
network of nerves of the neck
Where does the cervical plexus emerge from?
middle of the posterior border of the SCM (sternocleidomastoid)
What does the cervical plexus innervate?
- skin of anterolateral neck
- superolateral thoracic wall
- scalp between auricle and external occipital protuberance
What are the branches of the cervical plexus?
- lesser occipital nerve
- greater auricular nerve
- transverse cervical nerve
- supraclavicular nerves
What spinal nerve did the lesser occipital nerve originate from?
C2 spinal nerve
What does the lesser occipital nerve innervate?
sensory innervation to the skin above clavicle
Where can you find the lesser occipital nerve?
posterior border of the sternocleidomastoid
What spinal nerve did the supraclavicular nerve originate from?
C4 and C5 spinal nerves
What does the supraclavicular nerve innervate?
sensory innervation to skin above clavicle
Where can you find the supraclavicular nerve?
emerges as a common trunk under the posterior border of SCM (have to reflect that)
What spinal nerve did the phrenic nerve originate from?
C3, C4, C5 = keep the diaphragm alive!
What does the phrenic nerve innervate?
central portion of diaphragm
motor, sensory and sympathetic nerve fibers
Where can you find the phrenic nerve?
superior to (on top of) anterior scalene
What spinal nerve did the Ansa Cervicalis nerve originate from?
C1 and C2 spinal nerves
What does the Ansa Cervicalis nerve innervate?
motor innervation to infrahyoid muscles
Where can you find the Ansa Cervicalis nerve?
- behind omohyoid muscle
- superficial to (on top of) the internal jugular vein in the carotid sheath
What does the vagus nerve innervate?
abdominal and thoracic organs
Where can you find the vagus nerve on the neck?
- within the carotid sheath
- posterolateral to internal and common carotid arteries
- medial to internal jugular vein
What does the hypoglossal nerve innervate?
muscles of tongue
Where can you find the hypoglossal nerve on the neck?
runs horizontally behind stylohyoid and digastric inferior belly
Where can you find the vertebral artery on the neck?
- between common carotid and subclavian arteries
- perpendicular and under phrenic nerve
Where can you find the thyrocervical artery trunk on the neck?
medial first branch off of subclavian artery
Which arteries supply blood to the brain?
vertebral artery
What is a special feature of the carotid sinus and body?
has baroreceptors and chemoreceptors
Where does the internal carotid supply blood to?
brain
Where does the external carotid supply blood to?
face and neck
Where does the subclavian artery supply blood to?
upper limbs
Where does the thyrocervical trunk supply blood to?
thyroid gland and cervical regions