Muscular Flashcards

Myofibril

parallel threadlike structures. Play a fundamental role in muscle contraction

Sarcolemma

muscle cell membrane

Transverse tubule

allow depolarization of the membrane to quickly penetrate to the interior of the cell.

Sarcoplasmic reticulum

wraps around each myofibril and stores calcium

Sarcomere

functional unit for muscle contractions. defined by Z lines

Z line

line consisting of different proteins that bisect the I band

Myosin

Actin

Occipitalis

Raises eyebrow as when surprised

Frontalis

Raises eyebrow as when surprised

Orbicularis oculi

closes eye, blinking, wrinkles skin of forehead vertically as in frowning

Orbicularis oris

kissing muscle, shapes lips during speech

Zygomaticus major

Elevates and draws angle of mouth laterally, as in smiling and laughing

Zygomaticus minor

Elevates and everts upper lipFrown

Buccinator

tenses cheeks in blowing and whistling, aids closure of mouth

Temporalis

Mastication muscle, elevates mandible for chewing

Masseter

chewing muscle

Platysma

Depresses and wrinkles skin of lower face and mouth. Aids forced depression of mandible

Sternocleidomastoid

One side contracts, face turns to the opposite sideBoth muscles contract, the head bends toward the chest.

Trapezius

Large, triangular muscle Rotate the scapula raises scapula (shoulders) shrugging, pulling head backward

Rhomboid major

Retracts scapula. Elevates and rotates lower scapula back to rest position

Rhomboid minor

Retracts scapula. Rotates scapula to rest position

Levator scapulae

Raises medial border of scapula, Elevates scapula

Serratus anterior

pulls the scapula (shoulder blade) forward as in pushing or punchingPulls the scapula downward Used to thrust the shoulder forward, as when pushing something

Pectoralis major

bring arm forward across chest

Pectoralis minor

Pulls the scapula forward and downward.Raises the ribs and thus aid forceful inhalation

Latissimus dorsi

brings arm down and backward toward the bodyExtends and adducts the arms and rotates Aids in swimming, climbing

Diaphragm

Forms floor of thoracic cavity, involved in inspiration (breathing in)

Supraspinatus

Assist deltoid muscle in abducting arm at shoulder jointStabilizes shoulder joint

Infraspinatus

Laterally rotates arm and stabilizes shoulder joint

Deltoid

Laterally rotates arm and stabilizes shoulder joint

Subscapularis

Medially rotates arm and stabilizes shoulder joint

Teres minor

laterally rotates arm and stabilizes shoulder joint

Teres major

Medially rotates and adducts arm. Stabilizes shoulder joint

Biceps brachii

bends forearm at elbowFlexes forearm at elbow and shoulder joint.

Brachialis

strongest flexor of the elbow

Brachioradialis

Flexes arm at elbow and pronates (turning) forearm

Triceps brachii

elbow extension

Pronator teres

Rotates the arm medially as when the hand is turned so the palm is facing forward and flexes elbow

Linea alba

band of tough connective tissue. Extends from the xiphoid process to the pubis symphysis

External oblique

Supports abdominal wall, assists forced expiration, Tenses the abdominal wall

Internal oblique

Supports abdominal wall, assists forced respiration, abducts and rotates trunk. Tenses abdominal wall

Quadriceps femoris

raises thigh, straightens leg

Rectus abdominis

Flexes trunk, aids forced expiration and raise intra-abdominal pressure

Transverse abdominis

Supports abdominal wall, aids forced expiration and raising intra-abdominal pressure.

Gluteus maximus

Extends and laterally rotates hip. Maintains knee extended

Gluteus medius

Abducts and medially rotates hip. Tilts pelvis on walking

Tensor fasciae latae

Maintains knee extended (assists gluteus maximus) and abducts hip

Adductor longus

raises thighAdducts, flexes and rotates thigh laterally

Sartorius

flexes the leg and the thigh abducts the thigh and rotates it laterally

Gracilis

Adducts hip. Flexes knee

Biceps femoris

Hamstring muscleFlexes and laterally rotates kneebends leg at knee extend thigh back

Semitendinosus

Hamstring muscleFlexes and medially rotates knee. Extends hip

Rectus femoris

Extends knee

Vastus medialis

Extends knee

Vastus lateralis

Extends knee

Tibialis anterior

turn foot upward as when walking on heelsExtends and inverts foot at ankle.

Gastrocnemius

Plantar flexes foot turns foot downward as when standing on toes

Soleus

Plantar flexes foot