Neck/Head/Thorax/Spine/Abdomen Flashcards
(197 cards)
Sternocleidomastoid
ACTION
Bilateral: - flex head against resistance -neck flexion -extension at the A-O joint (posterior fibers only) -accessory muscle of respiration
Unilateral: -ipsilateral sidebend with contralateral rotation of the face
PROXIMAL: Sternal head: manubriu, Clavicular head: upper medial 1/3 clavicle DISTAL: to lateral surface of mastoid process & lateral 1/2 superior nuchal line
INNERVATION: CN XI (motor); C2, C3 ventral rami (sensory)

Anterior, Middle, Posterior Scalenes
ACTION
- Ipsilateral sidebending of cervical vertebra
- Reverse action: elevate first and second rib during inspiration
PROXIMAL
Anterior: transverse process CV3-CV6
Middle: post tubercles transverse process CV5-CV7
Posterior: post tubercles transverse process CV5-CV7
DISTAL
Anterior: 1st rib
Middle: sup surface 1st rib
Posterior: 2nd rib
INNERVATION
Anterior : C4-C6 ventral rami
Middle : ventral rami C3-C8
Posterior : ventral rami C7, C8

Levator Scapulae
ACTION
- Elevates scapula
- downward rotation of scapula with pec minor ms
PROXIMAL
-Posterior tubercles transverse processes of from CV1-CV4
DISTAL
-To medial border of scapula at & above the spine
INNERVATION
-C3-4 ventral rami; C5 ventral rami from dorsal scapular n.

Platysma
ACTION: depresses mandible and tenses skin of inferior face and neck
-Superficial to investing layer of fascia
INNERVATION: CN VII

Investing layer of fascia
Surrounds:
- trapezius
- sternocleidomastoid
- acts as roof to anterior triangle of neck

Pretracheal Fascia
Surrounds:
- thyroid gland
- infrahyoid (aka strap) muscles
- trachea
- esophagus (located deep to the trachea)

Prevertebral Fascia
Surrounds:

Prevertebral muscles, longus colli, longus capitus, Scaleni Musculature, Anterior Scalene, Middle Scalene, Posterior Scalene, Levator scapulae, Phrenic nerve, Deep muscles of the back
*Forms the floor of the posterior triangle
AKA: Fascial Carpet/ Floor
*prolonged laterally by forming the axillary sheath which invests the brachial plexus & vessels
Carotid Sheath
Surrounds:
- common carotid & int carotid artery
- internal jugular vein
- vagus nerve (CN X)
- sometimes ansa cervicalis (part of cervical plexus innervating strap muscles)
–> At times may lie superficial to carotid sheath
Anterior Triangle Borders
- roof- investing fascia & platysma
- superior- inferior border of the mandible
- anterior- median line of the neck
- posterior- anterior border of SCM
- Floor-prevertebral fascia

Anterior Triangle Contents
- muscular triangle: infrahyoid muscles, thyroid & parathyroid glands
- carotid triangle:common carotid a., internal jugular v., portions of last 3 cranial nerves
- digastric triangle: submandibular gland, facial artery, internal carotid a., internal jugular v., CN IX, CN X
Strap Muscles
Innervated by: ansa cervicalis of cervical plexus

- Sternohyoid
- Sternothyroid
- Thyrohyoid
- Omohyoid
Posterior Triangle Borders
- roof- fascia & platysma
- anterior- posterior border of SCM
- posterior- anterior border of trapezius muscle
- inferior- superficial aspect middle 1/3 of clavicle
- floor- prevertebral fascia

Posterior Triangle Contents
- transverse cervical a.
- CN XI
- upper trunk of brachial plexus
- subclavian a.
- dorsal scapular n.
- long thoracic n.
- n. to subclavius
- suprascapular a. & n.
Branches off of the subclavian A.
- Vertebral
- Internal thoracic
- Thyrocervical trunk which gives rise to 3 arteries: inferior thyroid, suprascapular, transverse cervical
- Costocervical trunk
- Dorsal scapular
Cervical Plexus
- formed by branches of ventral rami C1-4
- Supplies:
Nuchal (neck) muscles
diaphragm muscle
infrahyoid (strap) musculature
skin of head/neck/chest
-superficial branches (sensory only):
lesser occipital n. - C2
great auricular n. - C2,3
transverse cervical n. - C2,3
supraclavicular n. - C3,4
-Deep branches include:
Motor to prevertebral ms. - ventral rami C1-4
Motor to levator scapula and ant, middle, post scaleni
Motor to infrahyoid muscles via ansa cervicalis – ventral rami C1-3
Motor & sensory to diaphragm via the phrenic n. - C3-5 ventral rami
Sensory to SCM & trapezius- ventral rami C2,3 (NOT MOTOR, ARE SENSORY) (pain & proprioception)

Ansa Cervicalis
- that supplies the infrahyoid muscles (strap ms.)
- C1-3 ventral rami
- consists of two loops (aka roots)
- innervates: sternohyoid, sternothyroid, omohyoid, thyrohyoid
- innervation thyrohyoid: C1 ventral ramus however rides along with the hypoglossal nerve
Infrahyoid muscles
aka strap muscles
- anchor hyoid bone to sternum, clavicle & scapula
- action-depress hyoid bone & floor of mouth; elevate or depress larynx
- innervated by ansa cervicalis
- {thyrohyoid specifically C1 via CN XII}

Suprahyoid musucles
- digastric
- geniohyoid
- stylohyoid
- mylohyoid

Digastric
ACTION: depress mandible; elevates hyoid during swallowing
ATTACHMENT: Anterior and posterior bellies, from the digastric fossa of the mandible and the mastoid notch of the temporal bone to the intermediate tendon to body and greater horn of hyoid bone
INNERVATION: CN V/anterior belly,CN VII/posterior belly
**suprahyoid ms**

Geniohyoid

ACTION: depress mandible; elevates hyoid
ATTACHMENT: from the inferior mental spine of the mandible to the body of the hyoid
INNERVATION: C1 via CN XII
**suprahyoid ms**

Stylohyoid
ACTION: draws hyoid posteriorly & elevates it
ATTACHMENT: superior to post belly digastric, from the styloid process of the temporal bone to the body of they hyoid, superior!!!
INNERVATION: CN VII
**suprahyoid ms**

Mylohyoid

ACTION: elevates hyoid and floor of mouth
ATTACHMENT: mylohyoid line of the mandible and the mylohyoid raphe on the body of the hyoid one. , makes up floor of mouth
INNERVATION: CN V3 = mandibular br. of trigeminal n.
**suprahyoid ms*

External Carotid Artery Branches
- superior thyroid a.
- ascending pharyngeal a.
- lingual a.
- facial a.
- occipital a.
- posterior auricular a.
- superficial temporal a.
- maxillary (gives rise to meningeal a.)

Cranial Nerve VII (Facial Nerve)
PATH: cellbodies originate in pons and medulla–>through internal acoustic meatus and facial canal–> exits stylomastoid foramen
RESPONSIBILITIES:
- Motor supply to the muscles of facial expression
- (Bell’s Palsy-paralysis of muscles of facial expression; no apparent etiology/idiopathic; suspect edema 2’ infection)
- Motor: stylohyoid and posterior belly of digastric ms.
- Parasympathetic innervation (motor): secretion of tears (lacrimal gland) and saliva (sublingual and submandibular salivary glands)
- Special sensory: taste to anterior 2/3 of tongue and palate
To Zanzibar By Motor Car
- temporal
- zygomatic
- buccal
- mandibular
- cervical
*Most frequently paralyzed cranial nerve containing motor fibers*































































































































