Muscles of the Abdominal Wall Flashcards
Abdominal muscles form the abdominal wall that protects and supports the…
Abdominal Viscera
What actions to the abdominal muscles have on the trunk?
They flex and rotate it
What do they do to the abdomen in forced expiration?”
Compress the abdomen
Contraction of the abdominal musculature when _____ is closed greatly increases intra abdominal pressure. This structure lets air out of your lungs
Glottis
Increased pressure caused by the closed glottis that is necessary for urination, defecation, childbirth, coughing, vomiting, etc.
Valsalva Manuver
When abdominal pressure is greatly increased, what can result?
Hernia
Provides the attachment of lateral musculature of the abdomen
Rectus Sheath
What are the three horizontal, or oblique, abdominal muscles
External abdominal oblique
Internal abdominal oblique
Tranverse abdominal
The vertical abdominal muscle
Rectus abdominis
The very small triangular abdominal muscle
Pyramidalis
What structure separates the rectus abdominis longitudinally?
Linea alba
The structure that covers the rectus abdominis anteriorly and posteriorly
Rectus Sheath
3 or more transverse lines that separate the rectus abdominis to form a 6 pack
Tendinous Intersections
Origin and insertion of the rectus abdominis
Origin: Pubic Crest
Insertion: Zyphoid process of sternum and costal cartilage of ribs 5-7
Innervation (segmentally)
Intercostal Nerves
What is the action of the rectus abdominis?
Flexes lumbar region of vertebral column or flex the trunk
Most superficial of the 3 oblique horizontal abdominal muscles
External oblique
The inferior edge of the external oblique forms the
Inguinal Ligament
The medial edge of the inguinal ligament where there is an opening is the
Superficial inguinal ring
Origin and insertion of the external oblique
Origin: Lower 8 ribs
Inserts: Linea alba via
Innervation of the external oblique (segmentally)
Intercostal nerves
Action of the external oblique
Compresses the abdomen and flexes and roatates the trunk to the opposite side
The intermediate layer of the 3 flat muscles of the abdomen
Internal oblique
Origin and insertion of the internal oblique
Lumbodorsal fascia, Iliac crest, Lateral inguinal ligament
Insertion: Linea albea, last 3 ribs, pubic crest
innervation of the internal oblique
Intercostal nerves
Action
Compress abdomen
Rotates trunk
Flexes Trunk to the same side
The inner most layer of the 3 flat muscles of the abdomen
Transverse abdominis
Origin and insertion of the transverse abdominis
Origin: Inguinal ligament, thoracolumbar fascia, cartiliage of last 6 ribs, iliac crest
Insertion: Linea alba and pubic crest
Innervation of the transverse abdominis
Intercostal nerves
Action of the transverse abdominis
Compress the abdomen and abdominal contents
Review how the 3 flat muscles insert into linea alba by way of anterior and aponeurosis. Pictures are good
!!
A protrusion of some visceral structure through a normal or abnormal opening in the abdominal wall (like small intestine)
Inguinal hernias
90% of abdominal hernias in the ___ region
Inguinal (Duh)
75% are called indirect or ____ hernias that occur through the superficial inguinal ring to pass into scrotum OR labium majora
Congenital
Inguinal hernias are 20x more common in men. Why?
Because the spermatic chord also passes through the superficial inguinal ring, making it more accessible
This type of hernia occurs through a weak spot in the abdominal wall
Direct hernia
