Ach: Anterior Abdominal Wall and Inguinal Region Flashcards
What are the major regions of the anterior abdominal wall?
Upper- hypochondriac
Middle- lateral
Lower- inguinal
Epigastric
umbilical
hypogastric
What are the two layers of the superficial fascia?
- Outer fatty layer (campers)- continuous with the superficial fascia of the thorax
- Deep fibrous or membranous layer (scarpas)
Which layer of superficial fascia is important in closing abdominal incisions?
Outer fatty layer (camper’s fascia)
Which is confined to the lower abdominal wall and attaches to the deep fascia of the thigh just below the inguinal ligament?
Deep, fibrous layer
What is the Dartos layer?
Camper’s + Scarpa’s minus the fat plus smooth muscle
What is Colles fascia?
Fascia in the perineum that attaches to the urogenital diaphragm (part of the deep fibrous layer/Scarpa’s)
What is the linea alba?
Where the aponeurosis that covers the three pairs of flat muscles extends to anterior midline and intersect
What are the muscle layers arranged from superficial to deep of the anterior abdominal wall?
- External oblique
- internal oblique
- Transverus abdominus
What do the EO and IO do?
Compress viscera and flex and rotate the trunk
What is the conjoint tendon?
FIBROUS ARCH formed by the fusion of the aponeuroses of IO and TA muscles as they insert on the pectineal ligament.
What is the rectus abdominis?
Pair of strap muscles extending from the xiphoid process and adjacent costal cartilages (ribs 5-7) to the pubic crest.
What encloses the rectus abdominus?
Rectus sheath
Composed of anterior and posterior laminae of the aponeurotic portions of the oblique muscles.
The anterior layer of the rectus sheath provides points of attachment, tendinous intersections, to the anterior layer of the rectus muscles.
What is hte arcuate line?
Crescentic lower border of the posterior layer of the rectus sheath.
Above the arcuate line, the anterior layer is formed by the
aponeurosis of the external and internal obliques; below the arcuate line, by all three aponeurosis.
What is the transversalis fascia?
Lines the entire abdominopelvic cavity and is
separated from the peritoneum by a layer of fat-filled extraperitoneal connective tissue.
What is the median umbilical fold?
covering the median umbilical ligament;
remnant of the urachus, an embryonic connection between the bladder and the umbilicus
What is the medial umbilical fold?
covering the medial umbilical ligaments, which are the obliterated umbilical arteries
What is the lateral umbilical fold?
covering the inferior epigastric vessels.
What are the nerves of the anterior abdominal wall?
- Intercostal nerves (ventral rami of T7-T11)
- Subcostal nerve (T12 ventral ramus under rib 12)
- Ilioinguinal and iliohypogastric nerves (branches of L1)
What do the nerves of the anterior abdominal wall?
MOTOR to the muscles of the anterior abdominal wall (somatic efferent)
CUTANEOUS (somatic afferent) fibers from the anterolateral abdominal wall traveling in anterior and lateral cutaneous branches of these nerves
What does T10 supply?
the skin surrounding the umbilicus.
What are the arteries of the anterior abdominal wall?
- Superior epigastric artery
2. Inferior epigastric artery
The superior epigastric artery is a terminal branch of what artery?
Internal thoracic artery
Where is the superior epigastric artery located?
Descends behind rectus abdominis within the rectus sheath.
Anastomoses with inferior epigastric artery within rectus abdominis.
The inferior epigastric artery is a branch of what artery?
The external iliac artery just ABOVE the inguinal ligament
Where is the inferior epigastric artery located?
Ascends behind the rectus muscle w/in the rectus sheath
What intercostal and lumbar arteries supply the abdominal wall?
Lower two intercostal arteries
Four lumbar arteries
*Veins correspond to the arteries
What is an umbilical hernia?
Common in NEWBORNS because the anterior abdominal wall is relatively weak in the umbilical ring
Usually small, result from increased intra-abdominal pressure in the presence of incomplete closure of the anterior abdominal wall after ligation of the umbilical cord after birth
What is an acquired umbilical hernia?
occurs mostly in women and obese people, or as a result of trauma or surgical incisions; fat or peritoneum protrudes into the hernial sac
What is an epigastric hernia?
Located in the epigastric region through the linea alba
Where is a spigelian hernia located? What is a risk factor for it?
Located along the semilunar lines or arcuate line
Obesity is risk factor
What is an incisional hernia?
Protrusion of omentum or an organ through a surgical incision
What is the inguinal ligament?
The inwardly curved lower border of the external oblique aponeurosis.
Where is the inguinal ligament located?
Extends between the anterior superior iliac spine and the pubic tubercle.
What is the inguinal canal?
An oblique passage through the abdominal wall just above the inguinal ligament; formed by the processus vaginalis and the testes during development.
What is the gubernaculum testes?
a band of connective tissue that
attaches to the inferior pole of the gonad and to the labioscrotal fold
What follows the gubernaculum testes as they grow?
The “descent of the gonads”
What is the processus vaginalis?
a pouch of peritoneum that pushes through the anterior abdominal wall acquiring tubular coverings described below, and forming the inguinal canal
Where do the gonads descend?
retroperitoneally along the posterior abdominal wall
to the scrotum (male) following the processus and acquiring a covering from each of the abdominal layers
When do the gonads descend?
7th-8th month
What gives rise to the internal spermatic fascia?
Fascia transversalis
What gives rise to the cremasteric fascia and cremasteric muscle?
internal oblique muscle
What gives rise to the external spermatic fascia?
external oblique muscle
How does female development of the ovaries and inguinal canal differ from that of males?
In the female, the ovary remains in the pelvic cavity. The inguinal canal in females is formed the same way as males, but contains the ilioinguinal nerve and the female complement of the gubernaculum, the round ligament of the uterus, which terminates in the labia majora.
What are the contents of the inguinal canal?
- Spermatic cord (male)
- Round ligament of the uterus (female)
- Ilioinguinal nerve (L1)
What are the openings of the inguinal canal?
Deep inguinal ring (normal defect in fascia transversalis)
Superficial inguinal ring (triangular opening in the aponeurosis of the external oblique)
What are the boundaries of the inguinal canal?
Anterior - aponeurosis of external oblique; reinforced laterally by fibers of internal oblique.
Posterior - fascia transversalis laterally; conjoint tendon medially
Floor - rolled under edge of external oblique aponeurosis, lateral crus of superficial ring
Roof - arching lowest fibers of conjoint tendon
What are the structures of the spermatic cord passing to and from the testes which traverse the inguinal canal?
- ductus deferens
- testicular artery
- testicular vein
- lymph vessels
The testicular artery is an aortic branch from what level?
L2
The testicular vein forms what plexus?
pampiniform plexus
The lymph vessels in the spermatic cord drain to what nodes?
para-aortic nodes
What gives rise to the internal spermatic fascia?
fascia transversalis
What gives rise to the cremaster muscle and fascia?
internal oblique muscle
What gives rise to the external spermatic fascia?
external oblique muscle
What are the layers of the scrotum?
- Skin
- Dartos muscle
*Each scrotal sac contains the coverings of the spermatic cord and testis as extensions of the aponeurotic layers of the lower abdominal wall
What is the tunica vaginalis?
covers anterior and lateral sides of the TESTES; remnant of processus vaginalis
What is the tunica albuginea?
dense connective tissue covering of the testes
What are the lobules of the testes?
separated by septa and filled with coiled seminiferous tubules
What are the rete testis?
network of ductules drained by efferent ductules
What is the epididymis?
head, body and tail.
Collect sperm transmit to ductus deferens.
What is a hernia?
An abnormal protrusion of a viscus organ
Can be direct or indirect
What are the characteristics of an indirect inguinal hernia? Who is it most common in?
(1) Most common in male children
(2) Patent processus vaginalis
(3) Hernia structures follow route of testicular descent
(4) Acquires same coverings as those associated with spermatic cord
(5) Neck (where it exits the peritoneal cavity) of hernia lies lateral to inferior epigastric vessels, in the deep inguinal ring
What are the two types of indirect inguinal hernias and how do they differ?
Congenital: bowel herniates into a patent processus vaginalis (not
necessarily at birth).
Acquired: bowel herniates through deep inguinal ring, inguinal canal and the superficial ring, pushing before it a pouch of peritoneum. The hernia resects the stalk of the processus vaginalis.
What is a direct hernia?
(1) Bulges through posterior abdominal wall of inguinal canal in the region of the conjoint tendon.
In what populations are direct hernias most common?
Most common in elderly males with weak abdominal muscles
Becoming more common in females (weight lifting)
Where does the neck of a direct hernia lie compared to the epigastric vessels?
medial to the inferior epigastric vessels
What makes up the inguinal triangle?
- Lateral- inferior epigastric artery
- Medial- rectus abdominis
- Inferiorly- inguinal ligament
What type of hernia passes LATERAL to the inferior epigastric artery?
indirect
What type of hernia passes MEDIAL to the epigastric artery and WITHIN the triangle?
DIRECT
How does the femoral canal relate to hernias?
Femoral canal provides the route for femoral hernias BELOW the inguinal ligament
Femoral hernias are most common in what population?
Women b/c they have a wider pelvis
How do femoral hernias differ from inguinal hernias?
always LATERAL to the pubic tubercle, whereas inguinal are always MEDIAL to it
What is a varicocele?
the pampiniform plexus of veins may become dilated and tortuous (varicose) producing a varicocele (bag of worms).
What causes varicoceles?
These may result from defective valves in the testicular vein.
Kidney or other conditions that obstruct the renal vein can also result in distention of these veins.
Why are varicoceles commonly on the left side?
They occur 99% of the time on the left side because the angle at which the left testicular vein enters the left renal vein makes it more susceptible to obstruction or reversal of flow.
What is a hydrocele?
Excess fluid in a persistent processus vaginalis and may be associated with an indirect inguinal hernia. The visceral layer of the tunica vaginalis is secreting an abnormal amount of serous fluid
What is used to detect a hydrocele?
Transillumination
