Muscles of the abdominal region and pelvic floor

origin of diaphragm

Diploid process, ribs and costal cartilage 7-13

lumbar vertebrae

insertion of diaphragm

central tendon of diaphragm

action of diaphragm

prime mover of inhalation

origin of external intercostals

inferior margins of ribs 1-11

insertion of external intercostals

superior margin of next lower rib

action of external intercostals

elevate/protract ribs 2-12

expand thoracic cavity during inspiration

origin of internal intercostals

superior margins and costal cartilages of ribs 2-12

insertion of internal intercostals

inferior margin of next higher rib

action of internal intercostals

depress and retract ribs during expiration

origin of external abdominal oblique

ribs 5-10

insertion of external abdominal oblique

iliac crest

pubic symphysis

action of external abdominal oblique

flex and stabilize vertebral column

compress abdominal wall

maintain posture

origin of internal abdominal oblique

inguinal ligament

iliac crest

insertion of internal abdominal oblique

ribs 10-12

costal cartilages 7-10

pubis

action of internal abdominal oblique

flex and stabilize vertebral column

compress abdominal wall

maintain posture

origin of transverse abdominal

inguinal ligament

iliac crest

costal cartilages 7-10

insertion of transverse abdominal

linea alba

aponeurosis of internal oblique

action of transverse abdominal

compress abdominal contents

origin of rectus abdominus

pubic symphysis

superior margin of pubis

insertion of rectus abdominus

diploid process

costal cartilages 5-7

action of rectus abdominus

flex vertebral column

stabilize pelvic region during walking

compress abdominal viscera

action of erector spine (group)

sit/stand erect

straightens back after bending at waist

lateral flexion of waist

action of semispinalis thoracis

extension and contralateral rotation of vertebral column

action of quadratus lumborum

ipsilateral flexion of lumbar vertebral column

extends lumbar vertebral column

action of multifidus

stabilizes adjacent vertebrae

maintenance of posture

action of levator ani

compresses anal canal

reinforces external anal and urethral sphincters

supports pelvic viscera

action of ischiocavernosus

maintains erection of penis or clitoris

action of bulbocavernous

expels residual urine from urethra

aids in erection of penis or clitoris

action of deep transverse perineal

supports vaginal and urethral canals

action of compressor urethrae

ONLY in females

aids in urine retention

action of external anal sphincter

retained feces in rectum until voluntarily voided