lab quiz Flashcards
epicranus frontal belly
with aponeurosis fixed , frontal belly raises eyebrows
orbicularis oris
various parts can be activated individually, closes eyes produces blinking, squinting and draws eyebrows inferiorly
orbicularis oculi
draws eyebrows medially and inferiorly wrinkles skin of forehead
zygomatics major
rasies raises lateral corners of the mouth upwards
risorius
draws corner of lip laterally tenses lip,
mentalis
protrudes lower lip
buccinator
draws corner of mouth laterally, compresses cheek, holds food between teeth during chewing
temporalis
closes jaw, elevates and retracts mandible
masseter
prime mover of jaw closure
strenocleidomastodi
loacted deep to platysa on anterolateral surface neck, fleshy parts on either side indicate limits of anterior and posterior triangles on the neck.
origin: manubrium of sternum and medial portion of clavicle.
insertion: mastoid process of temporal bone and superior nuchal line of occipital bone
action: simultaneous contraction of both muscle of pair cuases flexion of neck forward, acting independently
Trapezius
location: most superficial muscle of posterior thorax, very broad orgin and insertion,
origin: occipital bone, ligamentum nuchae, spines of C7 and all thoracic vertebrae
insertion: acromion and spinous process of scapula, third of clavicle
action: extends head rasis,rotates and retracts scapula and stabilizes it
latissimus dorsi
location: broad flat muscle of lower back extensive superficial organ
orgin: indirect attachment to spinous processes of lower six thoracic vertebrae, lumber vertebrae last three to four ribs and iliac crest
insertion: floor of intertubercular sulcus of humerus
action: prime mover of arm extension adducts and medially rotates arm, brings arm down in power stroke as in striking a blow
rhombodis major+minor
location: beneath trapezius and inferior to levator scapulae rhomboid minor is the more superior muscle
origin: spinous processes of C7 and T1-T5
insertion: medial border of scapula
action: pull scapula medially, stabilize scapula, rotate glenoid cavity downward
Levator scapulae
located at and side of neck deep to trapezius, origin transverse process of c1-c4
insertion: medial border of scapula superior to spine, action:elevate and adduct scapula with fixed scapula laterally flexes neck to the same side
diaphragm
location: broad muscle forms floor of thoracic cavity dome shaped in relaxed state fiber converge from margins of thoracic cage toward a central tendon,
origin: inferior border of rib sternum, costal catilages of last six ribs and lumbar verebrae
insertion: central tendon,
action: prime mover of inspiration flattens on contraction, increasing vertical dimensions of thorax increases intra abdominal pressure.
pectoralis major
location: large fan shaped muscle covering upper portion of chest ,
origin: clavicle sternum, cartilage of ribs 1-6 and aponeurosis of external oblique muscle
insertion: fibers converge to insert by short tendon into intertubercular sulcus of humerus
action: prime mover of arm flexion, adducts medially rotates arm with arm fixed pulls chest upward in forced inspiration
serratus anterior
location: fan shaped muscle deep to scapula beneath and inferior to pectoral muscle on lateral rib cage,
orgin: later aspect os ribs 1-8
insertion: vertbral order of anterior surface of scapula
action: acting as a whole prime mover of arm abduction when only specific fibers are active can aid in flexion extension, and rotation of humerus
deltoid
location fleshy triangular muscle forming shoulder muscle mass: intramuscular injection site
origin lateral 1/3 of clavicle acrominon and spine of scapula
insertion: deltoid tuberosity of humerus
action: acting as a whole, prime mover of arm abduction when only specific fibers are active can aid in flexion extension and rotation of humerus
supraspinates
rotator cuff: location: obsucred by trapezius a rotator cuff muscle
origin: supraspinous fossa of scapula
insertion: greater tubercle of humerus
action: initaiates abduction of humerus stabilizes shoulder joint
infraspinatus
rotator cuff muscle location: partially covered by deltoid and trapezius
orgin: infraspinous fossa of scapula
insertion: greater tubercle of humerus
action: lateral rotation of humerus, helps hold head of humerus in glenoid cavity
teres minor
rotator cuff: location small muscle inferior to infraspinatus,
orgin: lateral margin of scapula
insertion: greater tubercle of humerus
action: as for infraspinatus
triceps brachii
location: sole large fleshy muscle of posterior humerus three headed origin,
origin: long head inferior margin of glenoid cavity lateral head posterior humerus medial head distal radial groove on posterior humerus
insertion: olecranon of ulna
action: powerful forearm extensor, antagonist of forarm flexors and biceps.
bicepes brachii
location: most familiar muscle of anterior humerus because this two headed muscle bulges when forearm is flexed
orgin: short head coracoid process long head supraglenoid turbercle and lip of glenoid cavity tendon of long head runs in intertubecular sulcus and within capsule of shoulder joint
insertion: radial tuberosity
action: flexion of elbow and supination of forearm
