Muscles

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Terms in this set (...)

Frontalis
covers the frontal bone, raises eyebrows, wrinkles forehead (aponeuroses: attach muscles indirectly to bones, cartilages, or connective tissue coverings); location: runs from cranial aponeurosis to the skin of eyebrows, where it inserts
Occipitalis
covers posterior aspect of the skull and pulls the scalp posteriorly; location: at posterior end of the cranial aponeurosis
orbicularis oculi
close your eyes, squint, blink, and wink; location: fibers that run in circles around the eyes
orbicularis oris
closes mouth and protrudes the lips; location: circular muscle of the lips
buccinator
flattens the cheek, chews; location: runs horizontally across the cheek and inserts into the orbicularis oris
Zygomaticus
raises corners of the mouth upward; location: extends from corner of mouth to the cheekbone
Masseter
covers the angle of the lower jaw, closes jaw by elevating mandible; location: runs from the zygomatic process of the temporal bone to the mandible
Temporalis
fan-shaped, inserts into the mandible and acts as a synergist of the masseter in closing the jaw; location: overlies the temporal bone
Platysma
single, sheetlike, covers the anterolateral neck, pulls the corners of the mouth inferiorly, producing a downward sag of the mouth; location: originates from the connective tissue covering of the chest muscles and inserts into the area around the mouth
Sternocleidomastoid
two-headed, when both muscles contract together, they flex the neck; location: one on each side of the neck, one head arises from the sternum and the other arises from the clavicle. the heads fuse before inserting into the mastoid process of the temporal bone
what do the trunk muscles include
(1) those that move the vertebral column (most of which are posterior antigravity muscles
(2) anterior thorax muscles, which move the ribs, head, and arms and,
(3) muscles of the abdominal wall, which help to move the vertebral column and, most important, form muscular "natural girdle" of the abdominal body wall
pectoralis major
fan-shaped, forms the anterior wall of the axilla and acts to adduct and flex the arm; location: originates in sternum, shoulder girlde, and first 6 ribs, inserts on the proximal end of humerus
intercostal muscles
external: help to raise rib cage when you inhale; internal: deep to external, depress the rib cage, helping to move air out of lungs when you exhale forcibly
rectus abdominus
strap-like and most superficial muscles of the abdomen, flex the vertebral column, compress abdominal contents during defecation and childbrith, involved in forced breathing; location: run from pubis to the rib cage, enclosed in an aponeurosis
external oblique
superficial muscles that make up the lateral walls of the abdomen, flex the vertebral column and rotate the trunk and bend it laterally; location: fibers run downward and medially from the last 8 ribs and insert into the ilium
internal oblique
deep to the external obliques, flex the vertebral column and rotate the trunk and bend it laterally; location: fibers run at right angles to those of the external obliques, arise from the iliac crest and insert into the last 3 ribs
transversus abdominus
deepest muscle of the abdominal wall, compresses the abdominal contents; location: fibers run horizontally across the abdomen, arises from the lower ribs and iliac crest and inserts into the pubis
trapezius
most superficial muscles of the posterior neck and upper trunk, form a diamond or kite-shaped muscle mass, extend the head, elevate, depress, adduct, and stabilize the scapula; location: each muscle runs from the occipital bone down the vertebral column to the end of the thoracic vertebrae, then flare laterally to insert on the scapular spine and clavicle antagonists of the sternocleidomastoids
latissimus dorsi
two large, flat muscles that cover the lower back, extends and adducts the humerus, important when the arm must be brought down in a power stroke; location: originate on the lower spine and ilium and then sweep superiorly to insert into the proximal end of the humerus
erector spinae
deep muscles of the back consisting of 3 muscle columns (longissimus, iliocostalis, spinalis) that collectively span the entire length of the vertebral column; prime mover of back extension and also provide resistance that helps control bending over at the waist
Quadratus Lumborum
Fleshy muscle forming part of the posterior abdominal wall that helps maintain upright posture; separately, each muscle of the pair flexes the spine laterally, together, they extend the lumbar spine; location: arise from iliac crests and insert into the upper lumbar vertebrae
Deltoid
abducts arm, location: curve of shoulder
groups of upper limb muscles
1) muscles that arise from shoulder girdle and cross the shoulder joint to insert into the humerus; 2) causes movement at the elbow joint, enclose the humerus and insert on the forearm bones; 3) muscles of the forearm, which insert on the hand bones and cause their movement, thin and spindle-shaped, many of them
triceps brachii
extends elbow, origin at shoulder girdle and proximal humerus, insertion at olecranon process of ulna
flexor carpi radialis
flexes wrist and abducts hand, origin at distal humerus, insertion at 2nd and 3rd metacarpals
flexor carpi ulnaris
flexes wrist and adducts hand, origin at distal humerus and posterior ulna, insertion at carpals of wrist and 5th metacarpal
flexor digitorum superficialis
flexes wrist and fingers, origin at distal humerus, ulna and radius, insertion at middle phalanges of 2nd to 5th metacarpals
extensor carpi radialis
extends wrist and abducts hand, origin at humerus, insertion at base of 2nd and 3rd metacarpals
extensor digitorum
extends fingers, origin at distal humberus, insertion at distal phalanges of 2nd to 5th fingers
biceps brachii
prime mover for flexion of the forearm and acts to supinate the forearm, location: originates by two heads from the shoulder girdle and inserts into the radial tuberosity
brachialis
deep to biceps, important for elbow flexion, lifts the ulna as the biceps lifts the radius
brachioradialis
fairly weak, arise on humerus and inserts into distal forearm, resides mainly in forearm
gluteus maximus
superficial muscle of the hip that forms most of the flesh of the butt, powerful hip extensor that acts to bring the thigh in a straight line with the pelvis, not very important in walking but the most important muscle for extending the hip when power is needed; location: originates from the sacrum and iliac bones, and inserts on the gluteal tuberosity of the femur and into the large tendinous iliotibial tract
gluteus medius
hip abductor, important in steadying the pelvis during walking and site for giving intramuscular injections; location: runs from ilium to the femur, beneath gluteus maximus for most of its length
iliopsoas
fused muscle composed of iliacus and psoas major, prime mover of hip flexion and acts to keep upper body from falling backward when we stand erect; location: runs from iliac bone and lower vertebrae deep inside pelvis to insert on lesser trochanter
adductor group
form muscle mass at the medial of each thigh, adduct thighs together; location: origin on pelvis and insert on proximal aspect of femur gravity does most of the work for them, they tend to become flabby easily
hamstring group
muscles forming the muscle mass of the posterior thigh, consist of biceps femoris, semimembranous, and semitendinosus, prime movers of thigh extension and knee flexion; location: origin on ischial tuberosity and run down thigh to insert on both sides of the proximal tibia
sartorius
thin, straplike, not too important compared to other thigh muscles, most superficial of the thigh, weak thigh muscle, acts as a synergist to bring about cross-legged position; location: runs obliquely across the thigh from the anterior iliac crest to the medial side of the tibia
Quadriceps group
consists of 4 muscles - rectus femoris and 3 vastus muscles - that flesh out the anterior thigh, acts to extend the knee powerfully, and can also help to flex the hip; location: vastus muscles originate from femur, rectus femoris orginates on pelvis, all 4 insert into tibial tuberosity via patellar ligament
tibialis anterior
superficial muscle on anterior leg, acts to dorsiflex and invert the foot; location: arises from upper tibia and then parallels the anterior crest as it runs to the tarsal bones, where it inserts by a long tendon
extensor digitorum longus
lateral to tibialis anterior, prime mover of toe extension; location: arises from lateral tibial condyle and proximal 3/4 of fibula and inserts into the phalanges of toes 2-5
fibularis muscles
longus, brevis, tertius, found on lateral part of the leg, plantar flexes and everts the foot; location: arise from fibula and insert into metatarsal bones of the foot
gastrocnemius
two-belied muscle that forms the curved calf of the posterior leg, prime mover for plantar flexion of the foot; location: arises by 2 heads, 1 from each side of the distal femur, and inserts through the calcaneal tendon into the heel of the foot
soleus
deep to gastrocnemius, fleshy, doesn't affect knee movement, inserts into the calcaneal tendon and strong plantar flexor of the foot; location: arises on the tibia and fibula
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