Abdomen Flashcards
(17 cards)
Fascia of anterolateral abdominal wall
Superficial to deep layers
Subcutaneous tissue
Superficial fatty layer
Deep membranous later
Three flat muscles of the abdomen
External oblique
Internal oblique
Transversus abdominis
What do all three flat muscles of the abdomen end and are like
End anteriorly in a strong sheet like aponeurosis
Forms the rectus sheath
What are the two vertical muscles of the abdomen
Rectus abdominis
Pyramidalis (not highlighted)
External oblique
Origin - external surfaces of 5-12 ribs
Insertion - linea alba, pubic tubercle and anterior half of iliac crest
Innervation - thoraco- abdominal nerves and subcostal nerve (anterior rami of t7-t11)
Action - compress and support abdominal viscera; flex and rotate trunk
Internal oblique
Origin - Thoracolumbar fascia anterior two thirds of iliac crest and connective tissue deep to inguinal ligament
Insertion - inferior borders of 10-12 ribs linea alba and pubis via conjoint tendon
Innervation - thoraco-abdominal nerves (anterior rami of t7-t11) and subcostal nerve
Action - compress and support abdominal viscera flex and rotate trunk
Transversus abdominis
Origin - internal surfaces of 7-12 costal cartilages thoraco-lumbar fascia iliac crest and connective tissue deep to inguinal ligament
Insertion - linea alba with aponeurosis of internal oblique pubic crest and pubis via conjoint tendon
Innervation - thoracic-abdominal nerves (anterior rami of t7-t11) subcostal and first lumbar
Action - compresses and supports abdominal viscera
Rectus abdominis
Origin - pubic symphysis and Pubic crest
Insertion - xiphoid process and 5-7 costal cartilages
Innervation - thoracic-abdominal and subcostal nerves (anterior rami of t7-t12 spinal nerves)
Actions - flexes trunk (lumbar vertebrae) and compresses abdominal viscera stabilizes and controls tilt of pelvis
Functions of abdominal muscles
Form a strong expandable support for this region
Protect the abdominal viscera from injury
Compress the abdominal viscera to maintain or increase intra-abdominal pressure.
Produce force required for defecation pee vomit and childbirth
Produce anterior and lateral flexion and rotation of the trunk and help maintain posture
Diaphragm
A dome shaped musculotendinous partition separating the thoracic and abdominal cavities
Chief muscle for inspiration
Forms convex floor of the thoracic cavity
Descends during inspiration
Three parts of diaphragm
Sternal part
- two muscular slips that attach to the posterior aspect of the xiphoid process of the sternum
Costal part
- consisting of wide muscular slips that attach to the internal surfaces of the inferior six costal cartilages and their adjoining ribs on each side forms the dome of the diaphragm
Lumbar part
- arising from two aponeurotic arches the medial and lateral arcuate ligaments and the three superior lumbar vertebrae
The posterior abdominal wall is composed mainly of
Five lumbar vertebrae and associated IV discs
Posterior abdominal wall muscles psoas quadratus lumborum iliacus transversus abdominis and internal and external oblique muscles
Lumbar plexus composed of the anterior rami of lumbar spinal nerves
Fascia including thoracolumbar fascia
Diaphragm contributing to the superior part of the posterior wall
Fat nerves vessels and lymph nodes
What are the posterior abdominal wall muscles
Psoas major
Iliacus
Quadratus lumborum
Psoas major
Superior - transverse processes of lumbar vertebrae: sides of bodies of t12 -s1 vertebrae and inervening IV discs
Inferior - by a strong tendon to lesser trochanter of femur
Innervation - lumbar plexus via anterior branches of nerves L2-L4
Action - acting inferiorly with iliacus flexes thigh; acting superiorly flexes vertebral column laterally to balance the trunk : when sitting acts inferiorly with iliacus to flex trunk
Iliacus
Superior - superior two thirds of Iliac fossa ala of sacrum and anterior sacro-iliac ligaments
Inferior - lesser trochanter of femur and shaft inferior to it and to psoas major tendon
Innervation - femoral nerve L2-L4
Action - flexes thigh and stabilizes hip joint acts with psoas major
Quadratus lumborum
Superior - medial half of inferior border of 12 rib and tips of lumbar transverse processes
Inferior - iliolumbar ligament and internal lip of iliac crest
Innervation - anterior branches of t12 and l1-l4
Actions - extends and laterally flexes vertebral column fixes 12 rib during inspiration
What are the three largest branches of the lumbar plexus
Obturator nerve (L2-L4)
Femoral nerve (L2-L4)
Lumbosacral trunk (L4, L5)
