Flashcards in Sievert Anatomy Week 1 Deck (76):
What are the three surface anatomy boundaries for the anterior abd wall?
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?
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 ____
What are the 5 layers of the abdominal wall?
muscle with investing fascia
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
In the abdominal wall, the ________ surrounds or invests any organs found intraperitoneally in the abdominal cavity
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
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
When does the superior epigastric artery end?
It runs until it meets deep inferior epigastric artery
Why are the superior and deep inferior epigastric arteries important?
They run within the sheath and provide collateral circulation to rectus muscle and abdominal wall
Why is the internal thoracic artery frequently used in bypass surgery?
Because of collateral flow from rib cage and from below
The deep inferior epigastric artery is a branch off the _______ and _________, the later of which anatomoses with the _____
external iliac artery, deep circumflex iliac, lumbar arteries
From where do the lumbar arteries arise? Where do they travel?
Lumbar arteries come off abdominal aorta and travel in neurovascular bundles between the two deepest layers - they look like intercostal arteries but found below the ribs.
The deep inferior epigastric artery makes up the ____ boundary of the inguinal triangle
True/False: It is possible to tie off the deep inferior epigastric artery where it meets the superior epigastric and attach it to the one of the coronary arteries because of an anastomotic connection
True/False: The blood supply in the rectus sheath is important clinically because it has an anastomotic connection between the blood supply of the internal mammary artery and blood from the iliacs
Describe venous drainage of the abdominal wall.
Venous drainage is accompanied by rich anastomotic connections between veins accompanying the arteries (lots of collateral flow)
Can have anterior abdominal wall blood go up to subclavian and SVC, or via intercostal veins which drain into azygos then SVC
The only unpredictable vessel in the abdominal wall is the obliterated umbilical vein. Why?
It contains numerous paraumbilical vein tribuaries that connect with other vessels in the skin. It travels into the anterior abdominal wall, heads superiorly, and makes connections with portal venous system and hepatic veins of liver.
After birth, the umbilical vein closes off but can be recanalized if there is liver cirrhosis or portal HTN. If recanalized, tributaries open back, called caput medusa.
What is the falciform ligament?
The falciform ligament is the ligament of peritoneum that attaches the liver to the anterior body wall.
What innervates the skin and muscle of the anterior abdominal wall?
T6-T11 intercostal nerves
subcostal nerve (T12)
What innervates the inferior aspect of the abdominal wall?
Why is this important?
L1 nerve via ilohypogastric and iloinguinal nerves [branches off the genitofemoral]
The ilioinguinal nerve is important because it innervates the anterior surface of labia and scrotum. Most of the cutaneous innervation to the genital area comes from the pudental nerve however. Therefore, need to anesthetize both for genital surgery.
True/False: All nerves of the anterior abd wall run between the two deepest layers and give off lateral and anterior cutaneous branches on the way.
What innervates the subxiphoid area of the anterior abd wall?
What innervates the umbilical area of the anterior abd wall?
What innervates the suprapubic area of the anterior abd wall?
L1 nerve via ilohypogastric and iloinguinal nerves [branches off the genitofemoral]
nerves run through inguinal canal and supply anterior wall of scrotum/labia majora
The inguinal canal is formed by the descent of the _____ in males and the _______ in females
testes, round ligament of the uterus
Where do the testes develop? Ovary?
Both develop in posterior abdominal wall then migrate.
Descent is controlled by the gubernaculum.
When the testes descend, what layers do they drag with them? These layers later make up the coverings of the spermatic cord.
peritoneum, transversalis fascia, internal oblique, external oblique
Describe the descent of the testes.
The testes sit within the transversalis layer.
The gubernaculum, attached to the testes, shortens and the testes travel down behind the peritoneal cavity.
They eventually leave the abdominal cavity and enter the scrotum.
In the process, some peritoneum is grabbed and pulled down. The tests get wrapped/invested in this sac and this termporary connection is then called the processus vaginalis.
Once the testicle is completely descended, the processus vaginalis deteriorates. The permanent coat of peritoneum that remains around the testicle is called the tunica vaginalis.
The remnant of the gubernaculum is a tiny bit that holds the testis to the sac.
The testes drag the external oblique muscle down to form the _____
The testes drag internal oblique muscle with them as they enter the _____
The spermatic cord starts _____ outside triangle and courses ____ to penetrate _____ to the triangle
laterally, medially, anterior
Describe the descent of the ovary
The gubernaculum is attached to the labia majora.
As the fetus grows, the gubernaculum shortens and pulls the ovary down.
The ovary gets close to the uterus at some point, it bumps into the uterus and fuses.
The round ligament of the ovary therefore becomes the round ligament of the uterus.
In most females, the processus vaginalis is completely closed off which is why indirect inguinal hernias are rare.
The inguinal triangle is defined by 3 borders. Describe.
The three borders are the:
medial border - rectus sheath
lateral border - inferior epigastric vessels
inferior border - inguinal ligament (poupart's ligament)
What determines the strength of the inguinal triangle?
the strength of the conjoint tendon
What is the conjoint tendon?
the conjoint tendon consists of the aponeurotic fibers of the internal oblique and transversus abdominis.
it arches across the triangle.
Why is a conjoint tendon with a high arch more likely to develop a hernia?
creates a weak area because the superficial ring is anterior to the triangle.
The weak area would be medial to the deep ring.
What is the difference between a direct and indirect hernia?
A direct hernia enters through a weakened area of the transversalis fascia within the inguinal triangle. It is not within the processus vaginalis. It exits via the superficial ring and does not enter the scrotum. The sac will be medial to inferior epigastric vessels.
An indirect hernia results from failure of embryonic closure of the deep ring after the testicle has passed through. It follows the course of the descent of the testes (within the processus vaginalis}. Therefore, it passes lateral to the inguinal triangle through the deep ring, into the superficial ring, and into the scrotum.
What layers are typically found in a direct hernia? Indirect? Why?
The sac of an indirect hernia will be surrounded by all layers of the spermatic cord. It will always have fibers from the internal oblique.
A direct hernia is not likely to have fibers from the internal oblique or transversus because it does not pass through under the conjoint tendon.
True/False: If a hernia protrudes from the superficial ring upon coughing, it is an indirect hernia
FALSE - cant tell difference between indirect and direct
True/False: 95% of hernias in males are indirect
In women, only a thin ligamentous structure called the _________ protrudes from the superficial ring
round ligament of the uterus
The round ligament of the uterus will ultimately fan out into the skin of the labia majora. What can be used as a market of this structure?
deep inferior epigastric artery
What are the three folds of the internal wall of the abd cavity and how are they formed?
1) lateral umbilical fold = deep inferior epigastric vessels
2) medial umbilical fold = obliterated umbilical arteries
3) midline AKA median fold =obliterated urachus
During the course of the testes through the abdominal wall, internal oblique gets pulled down creating the ____ and and the transversalis fascia gets pulled down creating the ______
cremaster muscle, internal spermatic fascia
True/False: There is no Camper's fascia in the scrotum because there is no fat
Name the 6 layers of the spermatic cord
Dartos, external spermadic fascia, cremaster muscle, internal spermadic fascia, tunica vaginalis (parietal), tunica vaginalis (visceral)
The ______ surrounding the artery, vein, and lymphatics in the femoral area is called the femoral sheath
True/False: The femoral nerve is found within the femoral sheath
The femoral canal is an empty space containing ______ which can enlarge slightly.
If the femoral canal enlarges, there is potential for loops of bowel to enter and get trapped. Why are femoral hernias dangerous?
They can become strangulated due to three solid boundaries.
There is an opening of the femoral canal in the abdominal cavity, above the pubic ramus. It is called the _____
The femoral ring is a blind space that has a few lymphatics coming down into the femoral cavity. Each lymphatic is accompanied by a _____ and _____ and drags _____ into the thigh for a short distance which ultimately fuses with the _______ of the thigh
vein, artery, transversalis fascia, investing fascia