Test 3 Flashcards
Rectus Abdominis
Origin: pubic crest and pubic symphysis
Insertion: cartilage of ribs 5-7 and xiphoid process
Action: flexes vertebral column especially lumbar portion, compresses abdomen to aid in pooping, peeing, forced breathing and childbirth. RMA: flexes pelvis on the vertebral column.
Sternocleidomastoid
Origin: sternal and clavicle
Insertion: temporal bone At the mastoid process
Action: work bilaterally the flex the cervical spine or flexes the head; laterally flexes neck and head to same side and rotates head to side opposite contracting muscle. Laterally rotate and flex head to opposite side side of contracting muscles. It can also extend the head upward if already looking up. Posterior fibers of muscle can assist in extension of head. RMA: elevate sternum during forced inhalation.
Innervations: accessory nerve (11) C2 and C3 also at the trapezius
External oblique
Origin: ribs 5-12
Insertion: lilac crest and linea alba
Action: act bilaterally, compress abdomen and flex vertebral column; acting unilaterally, laterally flex vertebral column, especially lumbar portion and rotate vertebral column.
Internal oblique
Origin: iliac crest, inguinal ligament and thoracolumbar fascia
Insertion: cartilage of ribs 7-10 and linea alba
Action: acting together compress abdomen and flex vertebral column; acting singly laterally flex vetebral coln especially lumbar portion and rotate vertebral column
Transversus Abdominis
Origin: iliac crest, inguinal ligament, lumbar fascia and cartilage of ribs 5-10.
Insertion: xiphoid process, linea alba and pubis
Action: compress abdomen
Quadratus lumborum
Origin: iliac crest and iliolumbar ligament
Insertion: inferior border of rib12 and L1-L4
Action: acting together, pull 12 rib inferiorly during forced breathing, fix 12 ribs to prevent their elevation during deep breathing, held extend lumbar portion of vc. Acting singly, laterally flex vc especially lumbar portion; RMA elevates hip bone commonly on one side
Diaphragm
Origin: xiphoid process of sternum, costal cartilage and adjacent portions of inferior 6 ribs, lumbar vertebrae and their intervertebral discs
Insertion: central tendon
Action: flattens and increases vertical dimensions thoracic cavity. Resulting in breathing
Innervations: phrenic nerve C3-C5
External intercostals
Origin: inferior border of rub above
Insertion: superior border of rib below
Action: results in inhalation and exhalation
Internal intercostals
Origin: superior border of rib below
Insertion: inferior border of rib above
Action: contraction draws adjacent ribs together to further decrease anteroposterior and lateral dimensions of thoracic cavity during forced exhalation
Levator Ani
Has two parts
Pubococcygeus and illioccygeus
Pubococcygeus
Origin: pubis and ischial spine
Insertion: coccyx
Action: supports and maintains position of pelvic viscera keeps everything in
illioccygeus
Origin: ischial spine
Insertion: coccyx
Action: supports and maintains position of pelvic viscera keeps everything in
Ischiococcygeus
Origin: ischial spine
Insertion: lower sacrum and upper coccyx
Action: supports and maintains position of pelvic viscera keeps everything in
Anterior scalene
Origin: transverse process of cervical
Insertion: first rib
Action: acting together: right and left as and ms muscles elevate first rib during deep inhalation
RMA: flex cervical vertebrae; acting singly laterally flex and slightly rotate cervical vertebrae
Middle scalene
Origin: transverse process of CErvical
Insertion: first rib
Action: acting together: right and left as and ms muscles elevate first rib during deep inhalation
RMA: flex cervical vertebrae; acting singly laterally flex and slightly rotate cervical vertebrae
