1-5 Anatomy of the Abdominal Wall & Inguinal Region Flashcards
What are the general boundaries of the abdominopelvic cavity?
extends from the thoracoabdominal diaphragm above to the pelvic diaphragm below
What generally makes up the abdominal wall and what does it do, in a general sense?
bones, fascia and muscles
Encloses the cylinder-like abdominal cavity
Serve to mobilize the abdomen while at the same time protect the abdominal contents
What are the osseous components of the abdominal wall?
1) Ribs 7-12
2) Lumbar vertebrae 1-5
3) Pelvis
What are the fascial components of the abdominal wall?
1) Anterior – rectus sheath
2) Posterior – thoracolumbar fascia
What are the muscular components of the abdominal wall?
1) External abdominal oblique
2) Internal abdominal oblique
3) Transversus abdominis
4) Rectus abdominis
5) Pyramidalis
6) Quadratus lumborum
7) Psoas major and minor
What are some superficial landmarks of the abdomen? For an extra slice of awkward cake, point them out on a partner.
- Xiphoid process (TV10)
- Costal margin
- Linea alba
- Umbilicus (LV 3-4 Interspace)
- Linea transversae (tendinous intersections)
- Linea semilunaris
- Pubic symphysis
- Pubic tubercle
- Inguinal ligament
- Anterior superior iliac spine (ASIS)
- Crest of ilium
What layers make up the superficial fascia in the abdominal wall?
Camper’s - fatty layer
Scarpa’s - membranous layer
Describe Camper’s/fatty layer of superficial fascia.
Description: most news anchors.
Actual description: superficial fatty layer
Where is the membranous layer of the superficial fascia best differentiated? What does it attach to?
Best differentiated below the level of the navel
It has definite attachments to the: Iliac crest Fascia lata below the inguinal ligament Pubic tubercle Pubic symphysis Perineal boundaries of the urogenital triangle
What forms the abdominal scrotal opening?
The abdominal scrotal opening formed by the weak attachment of the membranous layer to the pubic bone between the tubercle and symphysis
What are the specializations of the membranous layer of superficial fascia?
Fundiform ligament
Tunica dartos scroti
What is the fundiform ligament? Where is it located and what does it do?
robust development of membranous connective tissue
extends from the lower linea alba and passes lateral to the penis to end in the scrotal septum
provides support for the scrotum
What is the tunica dartos scroti? What tissues does it contain and what does it do?
Continuation of the fatty and membranous layers of superficial fascia into the scrotum as a single layer
Contains areolar tissue and smooth muscle
Responsible for wrinkling of the scrotal skin
What 3 groups of muscles compose the abominal wall?
Anterior
Anterolateral
Posterior
What muscles make up the anterior abdominal wall?
Rectus abdominis
Pyramidalis
What muscles make up the anterolateral abdominal wall?
External abdominal oblique
Internal abdominal oblique
Transversus abdominis
What muscles make up the posterior abdominal wall?
Psoas major
Psoas minor
Quadratus lumborum
Describe the fiber directions of anterior and anterolateral abdominal wall muscles. Why is this important?
The fiber direction of the anterolateral and anterior abdominal wall musculature is arranged so that successive layers assume a non-congruent orientation, viz., vertical, horizontal, and oblique directions
What is the innervation for the external abdominal oblique?
Intercostal nerves 7-11
subcostal nn
iliohypogastric nn
What is the action for the external abdominal oblique? What bodily fxns does it assist in?
Both sides acting:
flexion of the vertebral column and pelvis abdominal compression in defecation, parturition and forced expiration;
one side acting causes lateral flexion of the trunk with rotation to the OPPOSITE side
What is the innervation for the internal abdominal oblique?
Intercostal nerves 8-11
subcostal nn
iliohypogastric nn
ilioinguinal nn
What is the action for the internal abdominal oblique?
Both sides acting:
flexion of the vertebral column and pelvis
abdominal compression in defecation, parturition and forces expiration
one side acting causes lateral flexion of the trunk with rotation to the SAME side
What is the cremaster muscle derived from?
muscular layer of the spermatic cord derived from the internal abdominal oblique
What is a major difference in origins of the internal and external obliques?
Originate on different sides of abdominopelvic cavity
External oblique interdigitates with serratus anterior and lats, originates lower 8 ribs
Internal obliques originate on thoracolumbar fascia and inserts on lower ribs
What is the innervation of the transversus abdominis?
Intercostal nerves 8-11
subcostal n
iliohypogastric n
ilioguinal n.
What are the actions of the transversus abdominis? What doesn’t it do?
Contraction causes compression of the abdomen and its contents
no sidebends or flexion
What is the innervation of the rectus abdominis?
Intercostal nerves 7-11
subcostal n
What is the action of the rectus abdominis? What doesn’t it do?
Flexes the vertebral column and pelvis, assists in compression of the abdomen. – no sidebends
What determines if you have a 6-pack? An 8-pack?
Time of night? Whether or not you’re doing PTA?
Actually, due to tendinous intersections, which fuse to the anterior rectus sheath
What is the innervation for pyramidalis?
Subcostal nerve
What is the action for pyramidalis?
Small - tenses linea alba
What is the rectus sheath composed of?
combined aponeuroses of the external oblique, internal oblique, and transversus abdominis muscles