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.