abdominal muscles abdominal wall

ABDOMINAL MUSCLESABDOMINAL WALL

Kaan Yücel M.D., Ph.D. 24.April.2014 Thursday

enclose and protect abdominal contents while providing the flexibility required by respiration,

posture, and locomotion.

ABDOMINAL WALL

Anterior Lateral PosteriorAnterolateral

Rectus abdominis

Pyramidalis muscleFrom pubic bone to linea albaAnterior rami of T12

EXTERNAL OBLIQUE O

External surfaces of 5th-12th ribs

ILinea albaPubic tubercleAnterior half of iliac crest

T7-T11 spinal nerves and subcostal nerve

The lower border of the external oblique aponeurosis forms the inguinal ligament (Poupart’s ligament) thickened reinforced free edge of the external oblique aponeurosis between anterior superior iliac spine laterally and pubic tubercle medially. It folds under itself forming a trough, which plays an important role in the formation of the inguinal canal.

from extensions of the fibers at the medial end of the inguinal ligament:

lacunar ligament crescent-shaped extension of fibers at the medial end of the inguinal ligament

pass backward attach to pecten pubis on the superior ramus of the pubic bone

pectineal (Cooper's) ligamentfrom the lacunar ligament along the pecten pubis of the pelvic brim

INTERNAL OBLIQUE

OThoracolumbar fascia

Anterior 2/3 of iliac crestConnective tissue deep to lateral 1/3 of

inguinal ligament

IInferior borders of 10th-12th ribs

Linea albaPecten pubis via conjoint tendon

Anterior rami of T6-T12 spinal nerves) and first lumbar nerves

TRANSVERSUS ABDOMINIS

Internal surfaces of 7th-12th costal cartilages Thoracolumbar fasciaIliac crestConnective tissue deep to lateral 1/3 of inguinal ligament

O

ILinea alba with aponeurosis of internal oblique

Pubic crest

Pecten pubis via conjoint tendon

Anterior rami of T6-T12 spinal nerves) and first lumbar nerves

RECTUS ABDOMINIS

Anterior rami of T6-T12 spinal nerves) and first lumbar nerves

O: Pubic symphysis Pubic crest

I: Xp 5-7 costal cartilages

Rectus sheath unique layering of the aponeuroses of the external and internal oblique,

and transversus abdominis muscles

Ant. + Post. of ¾ rectus abdominis closed.Post. of ¼ rectus abdominis closed.

no sheath covers the posterior surface of the lower quarter of the rectus abdominis at this point is in direct contact with the transversalis fascia. Marking this point of transition is an arch of fibers (arcuate line).

Rectus sheath & Transversalis fasciaRectus sheathanterior wall aponeurosis of external oblique & half of aponeurosis of internal oblique, splits at lateral margin of rectus abdominisposterior wall other half of aponeurosis of internal oblique & aponeurosis of transversus abdominis

FUNCTIONS AND ACTIONS OF ANTEROLATERAL ABDOMINAL MUSCLES

Form a strong expandable support for the anterolateral abdominal wall.

Support the abdominal viscera and protect them from most injuries.

Compress the abdominal contents to maintain or increase the intra-abdominal pressure and, in so doing, oppose the diaphragm (increased intra-abdominal pressure facilitates expulsion).

Move the trunk and help to maintain posture.

SPINE FLEXIONRectus abdominis is a powerful flexor of the thoracic and especially lumbar regions of the vertebral column.

VIDEO HERE

SPINE LATERAL FLEXIONThe oblique abdominal muscles also assist in movements of the trunk, especially lateral flexion and rotation of the lumbar and lower thoracic vertebral column.

VIDEO HERE

SPINE ROTATION

VIDEO HERE

ABDOMINALCAVITY

parturition micturitiondefecationflatus

quiet and forced expiration by pushing the viscera upward (helps push the relaxed diaphragm further into the thoracic cavity) coughing vomitingsneezingeructationscreaming

Psoas majorPsoas minor (80%)Quadratus lumborumIliacus

Psoas majorfills the space between vertebral bodies &transverse processes

Anterior rami of L1, L2, L3

Flexion of thighLateral flexion of spine

Psoas minor (80%)Anterior rami of L1Weak flexion of lumbar vertebral column

Iliacusfills the iliac fossa on each side.

Psoas major + Iliacus = Iliopsoas

Lesser troachanter of femur

chief flexor of the thigh

Femoral nerve

Quadratus lumborum

fill the space between ribs XII and the iliac crest on both sides of the vertebral column.

Transverse process of L5, Iliolumbar ligament, iliac crest

Transverse process of first four lumbar vertebrae and the inferior border of rib XII

O

I

Depress and stabilize 12th ribs Lateral bending of the trunk. Acting together, extend lumbar part of the spine.

anterior rami of T12 and

L1 to L4 spinal nerves

http://www.getbodysmart.com

VIDEO HERE

The superficial fatty layer of superficial fascia (Camper's fascia) continuous over the inguinal ligament with the superficial fascia of the thigh and with a similar layer in the perineum.

In men, continues over the penis and, fusing with the deeper layer of superficial fascia, continues into the scrotum specialized fascial layer containing smooth muscle fibers (the dartos fascia). In women, retains some fat and is a component of the labia majora.

The deeper membranous layer of superficial fascia (Scarpa's fascia)

thin and membranouscontains little or no fat.

Inferiorly, continues into the thigh, just below the inguinal ligament, fuses with

deep fascia of the thigh (the fascia lata).

In the midline, firmly attached to the linea alba & symphysis pubis.

continues into the anterior part of the perineum where it is firmly attached to

the ischiopubic rami and to the posterior margin of the perineal membrane.

Here, referred to as superficial perineal fascia (Colles' fascia).