Sievert Anatomy Week 1 Flashcards
What are the three surface anatomy boundaries for the anterior abd wall?
1) Superior
2) Inferior
3) Lateral
What is the superior surface anatomy boundary of the anterior abd wall?
right and left costal marigins of the 7-10th ribs, xiphoid process
What is the inferior surface anatomy boundary of the anterior abdominal wall?
inguinal ligament
superior marigins of the pelvic girdle
What is the lateral surface anatomy boundary of the anterior abdominal wall?
lateral abd wall lol
True/False: The anterior abdominal wall soft tissues are restricted to the superior, inferior, and lateral boundaries
FALSE - for example, many of anterior wall muscles have much more extensive origins and insertions
The anterior abdomen is subdivided into 4 quadrants with a horizontal line through the _____ and a vertical line through the ____
umbilicus, midline
What are the 5 layers of the abdominal wall?
skin superficial fascia muscle with investing fascia transversalis fascia parietal peritoneum
The superficial layer contains two layers. Name and briefly describe.
1) Camper’s - superficial fatty layer
2) Scarpa’s - deep membranous layer continuous with superficial perineal fascia, no fat
There is a potential space between Scarpa’s fascia and the investing fascia of the external oblique muscle. Describe how thise relates to extravasation of urine.
If the urethra ruptures from an accident, urine can extravasate into this space.
The scarpa’s fascia does not communicate with the thigh however because it fuses with the fascia lata at the inguinal ligament [line where thigh meets inguinal region]
Therefore, urine will not enter thigh
True/False: All muscles have investing fascia in superficial and deep surfaces
True
In the abdominal wall, the ________ surrounds or invests any organs found intraperitoneally in the abdominal cavity
visceral peritoneum
What is the transversalis fascia? Why is it important?
It is a transparent fascia that lines the entire abdominal wall.
It binds peritoneum to the deep layer of investing fascia.
It is located deep to the transversus abdominis muscle.
Testes and ovaries develop in this fascia.
Its name changes depending on the position (diaphragmmatic, pelvic fascia)
Describe the parietal peritoneum in the anterior abdomen
It is intimately in contact with the body wall and fused to all surface of the abdominal wall, except for where it covers certain organs that are retroperitoneal.
It lines the coelomic sac.
They may be fat between the peritoneum and the transversalis fascia.
What is the difference between retroperitoneal and secondary retroperitoneal?
Retroperitoneal develop behind coelomic sac and nerves push into it; they are only covered by peritoneum on their anterior surface and are located btwn parietal peritoneum and posterior abd wall
Secondary retroperitoneal organs develop into the coelomic sac and are covered by peritoneum but due to movement of the body cavity and pressure of the organ against the body wall, become retroperitoneal.
[ Wiki - organs that were once suspended within the abd cavity by mesentery but migrated posterior to peritoneum during the course of embryogenesis to become retroperitoneal are considered secondarily retroperitoneal ]
What are the four anterior abdominal wall muscles?
external oblique, internal oblique, transversus abdominis, rectus abdominis
Where do the four anterior abdominal wall muscles arise?
The external oblique arises from the surface of ribs 5-12.
The internal oblique and transversus abdominis both arise posteriorly from the thoraco-lumbar fascia.
- internal oblique from lateral part
- transversus abdominis from 7-12 costal cartilages
The internal oblique and transversus abdominis both arise inferiorly from the iliac crest
- internal oblique from lateral 1/2 inguinal ligament
- transversus from lateral 1/3 inguinal ligament
The rectus abdominis arises inferiorly from pubic symphysis and crest
Where do the four anterior abdominal wall muscles insert?
The external and internal obliques and transversus all insert into the linea alba.
The internal oblique and transversus abdominis insert into the pecten pubis and pubic crest via the conjoint tendon.
The external oblique also inserts into the anterior iliac crest and pubic tubercle.
The internal oblique insets into the lower ribs, with its fibers running perpendicular to external.
The tranversus abdominis fibers run parallel to transverse plane.
The rectus abdominis inserts into the xiphoid process and 5th-7th costal cartilages, courses superiorly to insert.
What is the source of innervation for the 4 anterior abdominal wall muscles?
Internal oblique, transversus abdominis and rectus abdominis are innervated by T6-T11 intercostal nerves and the subcostal nerve.
in addition, the internal oblique and transversus abdominis are innervated by L1 spinal.
The external oblique is innervated by T7-T12
*subcostal=T12
Describe the actions of the anterior abdominal wall muscles
The internal and external obliques and rectus abdominis all assist will flexion against resistance.
The internal oblique, transversus, and rectus abdominis all compress the abdominal viscera.
The internal oblique and transversus abdominis support intrinsic back muscles due to origin from thoracolumbar fascia
The external oblique rotates the trunk to the opposite side, while the internal oblique rotate the trunk to the same side.
The rectus abdominis stabilizes the tilt of the pelvis
Describe clinically significant characteristics of the external oblique
inferior border of external oblique creates the inguinal ligament
incisions can be made along the linea alba without damaging the nerve supply
The inguinal ligament is defined by the point of attachment between ________ and _______
anterior iliac spine, pubic tubercle
Describe clinically significant characteristics of the internal oblique
When testes descend, pick up fibers from internal oblique because in lateral 1/2 inguinal ligament –> cremaster muscle
Can strength to help back injuries
Describe the clinically significant characteristics of the transversus abdominis
The peritoneum is located directly underneath the transversus abdominis muscle
Can also be strengthened to help back injuries
When testes descend, DO NOT pick up fibers from here because located in the lateral 1/3 of inguinal ligament
Describe the rectus abdominis
It is sheathed by the rectus sheath up until the arcuate line.
They are two paired muscled divided into four bellies each by tendinous intersections.
Linear alba is located midline where two sides come together.
The inferior aspect does not have tendinous inscriptions due to anastomotic connections.
In the rectus abdominis, how does each packet receive innervation?
From nerve that runs posteriorly between transversus and internal oblique.
This can be deinnervated by surgical procedures - muscle will undergo atrophy and become fatty
The rectus sheath is a connective tissue sleeve formed by the aponeurotic tendons of the lateral 3 abdominal wall muscles. Name them.
External obliques, internal obliques, part of transversus abdominis
The rectus sheath contains the arcuate line. Describe what this line marks and how the fibers run above or below this line.
The arcuate line is located halfway between the umbilicus and pubic symphysis and marks where the rectus sheath ends.
Above the arcuate line, the fibers of transversus pass posterior to rectus abdominis. External runs anterior. Internal splits and goes both ways.
Below arcuate line, the fibers all pass anterior to the rectus muscle. All there is behind muscle is the investing fascia of that muscle, transversalis fascia, and peritoneum.
The rectus sheath also includes the linea alba. What is this structure?
It is an interdigitation of all aponeurotic fibers in the midline.
Name the five arteries that provide the blood supply to the anterior abdominal wall.
superior epigastric artery, deep inferior epigastric, T10 and T11 intercostals, musculophrenic arteries, subcostal artery
The superior epigastric artery is the end of the ________ and a branch of the _______. It enters the rectus sheath just below the _____ and stays in the posterior aspect of the muscle.
internal thoracic artery, subclavian artery, the ribs