Muscles Flashcards
Diaphragm
Dome-shaped muscle separating the thoracic cavity from the abdominal cavity.
Assists in breathing (contraction increases the volume of the thorax and inflates the lungs). Hiccups.
Epicranius, frontal belly
Covers frontal bone.
Allows raising of eyebrows and wrinkling forehead.
Intercostals, external
Found between the ribs.
Help to raise the rib cage when inhaling.
Masseter
Covers angle of lower jaw.
Closes the jaw by elevating the mandible.
Obliques, external
Paired superficial muscles, make up lateral walls of abdomen.
Flexes and rotates vertebral column.
Obliques, internal
Paired muscles deep to the external obliques.
Same function as externals (flexes and rotates vertebral column).
Orbicularis oris
Circular muscle of the lips.
Closes mouth and protrudes lips.
Orbicularis oculi
Fibers that run in circles around eyes.
Allows blinking, squinting, winking, closing eyes.
Pectoralis major
Fan-shaped muscle covering the upper part of the chest, forms anterior wall of axilla.
Adducts and flexes humerus.
Pectoralis minor
Deep to the pectoralis major.
Draws down the scapula or raises the ribs.
Rectus abdominus
Most superficial muscles of abdomen.
Flexes vertebral column.
Serratus anterior
Passes between scapula and rib cage.
Protraction and superior rotation of scapula, holds scapula against thoracic wall.
Sternocleidomastoid
Paired two-headed muscles connecting the sternum and clavicle to the mastoid process.
Flexes neck, rotates head.
Temporalis
Fan shaped, overlies temporal bone.
Synergist of masseter in closing the jaw.
Trapezius
Most superficial muscles of posterior neck and upper trunk.
Extends the neck, adducts scapula.
Transversus abdominus
Deepest muscle of abdominal wall, runs horizontally across abdomen.
Compresses abdominal contents.
Zygomaticus
Corner of mouth to cheekbone.
Raises corners of mouth upwards (smiles).
Epicranius, occipital belly
Covers posterior aspect of skull.
Pulls scalp posteriorly.
Intercostals, internal
Between the ribs and deep to the external intercostals.
Depress rib cage (forcible exhalation).
Adductor longus
Forms muscle mass at medial side of thigh.
Adducts thigh, flexes hip, medially rotates leg/hip.
Biceps brachii
Bulges when elbow is flexed.
Elbow flexion (lifts the radius) and forearm supination.
Biceps femoris
Hamstring group, forms the muscle mass of the posterior thigh.
Flexes knee, extends hip, laterally rotates hip.
Brachialis
Deep to the biceps brachii. Elbow flexion (lifts the ulna)
Brachioradialis
Weak muscle, resides in the forearm.
Elbow flexion.
Deltoid
Fleshy triangle-shaped muscles that form the rounded shape of the shoulder.
Abducts and rotates arm.
Gastrocnemius
Two-bellied muscle that forms the calf.
Plantar flexion of foot and flexion of knee.
Gluteus Maximus
Superficial muscle of the hip, forms most of the flesh of the buttock.
Abducts thigh, extends hip (when forceful extension is required), and laterally rotates leg/hip.
Gluteus Medius
Runs from ilium to femur, beneath gluteus maximus.
Abducts thigh, medially rotates leg/hip, steadies pelvis during walking.
Gracilis
Adducts thigh, flexes knee, medially rotates leg/hip.
Latissimus dorsi
Two large flat muscles that cover the lower back.
Extends and abducts humerus.
Pectineus
Adducts thigh, flexes hip, medially rotates leg/hip.
Rectus femoris
Quadriceps group, fleshes out the anterior thigh.
Extends knee, flexes hip.
Sartorius
Thin, straplike, most superficial muscle of the thigh.
Flexes hip and knee, laterally rotates hip. (Acts as synergist to bring about cross-legged position.)
Semimembranosus
Hamstring group, forms the muscle mass of the posterior thigh.
Flexes knee, extends hip, medially rotates leg/hip.
Semitendinosus
Hamstring group, forms the muscle mass of the posterior thigh.
Flexes knee, extends hip, medially rotates leg/hip.
Soleus
Deep to the gastrocnemius.
Plantar flexion of foot.
Tensor fasciae latae
Flexes and medially rotates hip; steadies trunk on thigh while standing.
Tibialis anterior
Superficial muscle on the anterior leg.
Dorsiflexion and inversion of foot.
Triceps brachii
Three-headed muscle, fleshes out the posterior humerus. Antagonist of biceps brachii.
Extends elbow.
Vastus intermedius
Deep to rectus femoris.
Extends knee.
Vastus lateralis
Quadriceps group, fleshes out the anterior thigh.
Extends knee.
Vastus medialis
Quadriceps group, fleshes out the anterior thigh.
Extends knee.
