Muscles Flashcards
Intercostal (external)
attachments - from rib to rib oriented from superior-lateral to inferior-medial
actions - elevation of ribs
innervation - intercostal nerve
Intercostal (internal & innermost)
attachments - from rib to rib oriented superior-medial to inferior-lateral
actions - depression of ribs
innervation - intercostal nerve
transversus thoracis
attachments - from posterior sternum to costal cartilages
actions - depress ribs
innervation - intercostal nerves
cremaster
attachments - from the medial edge of the internal oblique to spermatic cord
actions - elevation of testis
innervation - genitofemoral nerve
diaphragm
attachments - from xiphoid process, inner surface of the lower ribs & costal cartilages, medial & lateral arcuate ligaments & lumbar vertebrae via the crura to the central tendon
actions - inspiration (negative thoracic pressure by inferior displacement)
innervation - phrenic nerve
external oblique
attachments - from lower 8 ribs to iliac crest & rectus sheath
actions - flexion & rotation of the trunk, & compression of the abdominal cavity
innervation - ventral rami T7-12
internal oblique
attachments - from thoracolumbar fascia to inguinal ligament, iliac crest & rectus sheath
actions - flexion & rotation of the trunk, &
compression of the abdominal cavity
innervation - lower thoracic & L1 ventral rami
quadratus lumborum
attachments - from 12th rib to iliolumbar ligament & iliac crest
actions - extension & lateral flexion of the trunk, and fixes 12th rib during respiration
innervation - ventral rami T12-L3
rectus abdominis
attachments - from xiphoid process & adjacent costal cartilages to pubic crest & tubercle
actions - flexion of trunk & compression of abdominal cavity
innervation - lower thoracic ventral rami
transversus abdominis
attachments - from lower six costal cartilages & thoracolumbar fascia to inguinal ligament, iliac crest & rectus sheath
actions - compression of the abdominal cavity
innervation - lower thoracic & L1 ventral rami
coccygeus
attachments - from ischial spine & sacrospinous ligament to coccyx
actions - supports & compresses posterior pelvic floor
innervation - ventral rami S4-5
levator ani
attachments - from pubic symphysis, obturator fascia & ischial spine to midline raphe & anococcygeal ligament
actions - supports pelvic viscera, & compresses rectum & vagina
innervation - pudendal nerve (inferior rectal branches) & S4
bulbospongiousus
attachments - in male from median raphe & perineal body (central tendon) to surround bulb of penis; in female from the perineal body to surround vestibular bulb, vaginal orifice & clitoris
actions - in male empties urethra, maintains erection & contracts during ejaculation; in female constricts vaginal orifice & contributes to erection of clitoris
innervation - perineal branch of pudendal nerve
ischiocavernosus
attachments - from ischial tuberosity & ramus to aponeurosis surrounding crus of penis or clitoris
actions - compresses crus during erection
innervation - perineal branch of pudendal nerve
sphincter ani externus
attachments - from perineal body (central tendon) to anococcygeal raphe
actions - closes anal canal & fixes perineal body
innervation - inferior rectal branch of pudendal nerve
sphincter urethrae
attachments - surrounds urethra
actions - compresses urethra
innervation - perineal branch of pudendal nerve
compressor urethrae
attachments - in the female from the ischiopubic ramus to midline passing ventral to the urethra and inferior to the sphinchter urethrae with a variable number of fibers fanning out medially to reach the vagina (thus replacing the deep transverse perineus)
actions - compresses urethra
innervation - perineal branch of the pudendal nerve
Sphincter urethrovaginalis
attachments - from perineal body, surrounds vagina & urethra to meet contralateral muscle inferior to compressor urethrea
actions - compresses urethra & vagina
innervation - perineal branch of the pudendal nerve
Deep transverse perineus
attachments - from ischial tuberosity to perineal body (central tendon)
actions - fixes perineal body
innervation - perineal branch of pudendal nerve
superficial transverse perineus
attachments - from ischial tuberosity to perineal body (central tendon)
actions - fixes perineal body
innervation - perineal branch of the pudendal nerve
iliacus
attachments - from iliac fossa, iliac crest & sacrum to the lesser trochanter of the femur
actions - flexes thigh and stabilizes hip joint
innervation - femoral nerve & lumbar plexus branches
psoas
attachments - from anterior lumbar transverse processes vertebral bodies & discs to the lesser trochanter of the femur
actions - flexes thigh and stabilizes hip joint
innervation - ventral rami L1-3
piriformis
attachments - from the anterolateral sacrum & posterior inferior iliac spine to the upper border of the greater trochanter
actions - abducts & laterally rotates thigh
innervation - branches of the lumbosacral plexus
obturator internus
attachments - from the anterolateral wall of the pelvis & obturator membrane to the medial surface of the greater trochanter
actions - laterally rotates thigh
innervation - nerve to the obturator internus
