U of M inguinal region Flashcards
During a laparoscopic examination of the deep surface of the lower anterior abdominal wall (using a lighted scope on a thin tube inserted through the wall), the attending physician noted something of interest and asked the young resident to look at the medial inguinal fossa. To do so, the young doctor would have to look at the area between the:
inferior epigastric artery and urachus
medial umbilical ligament and urachus
inferior epigastric artery and lateral umbilical fold
medial umbilical ligament and inferior epigastric artery
median umbilical ligament and medial umbilical ligament
The correct answer is: medial umbilical ligament and inferior epigastric artery
Remember, the medial umbilical fold is made by the medial umbilical ligament (the obliterated portion of the umbilical artery), while the lateral umbilical fold is a fold of peritoneum over the inferior epigastric vessels. The median umibilical fold is a midline structure made by the median umbilical ligament (obliterated urachus). The medial inguinal fossa is the space on the inner abdominal wall between the medial umbilical fold and the lateral umbilical fold. This is the place in the abdominal wall where there is an area of weak fascia called the inguinal triangle–direct inguinal hernias can break through this space. The lateral inguinal fossa is a space lateral to the lateral umbilical fold–indirect inguinal hernias push through the deep inguinal ring in this space.
If one were to make an incision parallel to and 2 inches above the inguinal ligament, one would find the inferior epigastric vessels between which layers of the abdominal wall?
Camper’s and Scarpa’s fascias
External abdominal oblique and internal abdominal oblique muscles
Internal abdominal oblique and transversus abdominis muscles
Skin and deep fascia of the abdominal wall
Tranversus abdominis muscle and peritoneum
The correct answer is: transversus abdominis and peritoneum
The inferior epigastric vessels lay on the inner surface of the transversus abdominis and are covered by parietal peritoneum. Remember, the peritoneum lies over the inferior epigastric vessels to make the lateral umbilical fold. Camper’s fascia and Scarpa’s fascia are two layers of the superficial fascia - Camper’s is the fatty layer and Scarpa’s is the membranous layer.
A man is moving into a new house and during the process lifts a large chest of drawers. As he lifts he feels a severe pain in the lower right quadrant of his abdomen. He finds that he can no longer lift without pain and the next day goes to see his physician. Surgery is indicated and during the surgery the surgeon opens the inguinal region and finds a hernial sac with a small knuckle of intestine projecting through the abdominal wall just above the inguinal ligament and lateral to the inferior epigastric vessels. The hernia was diagnosed as:
A congenital inguinal hernia
A direct inguinal hernia
A femoral hernia
An incisional hernia
An indirect inguinal hernia
The correct answer is: An indirect inguinal hernia
An indirect inguinal hernia leaves the abdominal cavity lateral to the inferior epigastric vessels and enters the inguinal canal through the deep inguinal ring. Commonly, these hernias traverse the entire inguinal canal, leave the canal through the superficial inguinal ring, and enter the scrotum. The indirect inguinal hernias are the most common type of hernia, and are often caused by heavy lifting. Direct inguinal hernias leave the abdominal cavity medial to the inferior epigastric vessels, through the weak fascia. These usually do not traverse the entire inguinal canal, and they rarely enter the scrotum. Direct inguinal hernias may be caused by a weakness of abdominal musculature.
Which structure passes through the deep inguinal ring?
Iliohypogastric nerve
Ilioinguinal nerve
Inferior epigastric artery
Medial umbilical ligament
Round ligament of the uterus
The correct answer is: round ligament of the uterus
The round ligament of the uterus passes through the deep inguinal ring and runs through the inguinal canal. It is a derivative of the gubernaculum, a structure which pulled the gonads into place during embryonic development. In males, the scrotal ligament is what remains from the gubernaculum. Also keep in mind that, in males, the spermatic cord passes through the deep inguinal ring. Of the other answer choices, the ilioinguinal nerve is the only other one that courses through the inguinal canal. Remember–it leaves through the superficial ring and gives off the anterior labial or scrotal branch as a cutaneous continuation. However, the ilioinguinal nerve does not pass through the deep ring - it enters the inguinal canal on the side.
The iliohypogastric nerves run between the internal oblique and transversus abdominis in the abdominal wall, piercing the internal oblique at the anterior superior iliac spine to travel deep to just the external oblique. The inferior epigastric artery runs between the transversus abdominis and the peritoneum, forming the lateral umbilical fold. The medial umbilical ligament is the obliterated umbilical artery–it lies within the medial umbilical fold of peritoneum.
A loop of bowel protrudes through the abdominal wall to form a direct inguinal hernia; viewed from the abdominal side, the hernial sac would be found in which region?
Deep inguinal ring
Lateral inguinal fossa
Medial inguinal fossa
Superficial inguinal ring
Supravesical fossa
The correct answer is: medial inguinal fossa
A direct inguinal hernia passes through the weak fascia in the medial inguinal fossa. This is the area between the medial and lateral umbilical folds (made of the obliterated umbilical artery and inferior epigastric vessels, respectively). A direct inguinal hernia does not pass through the deep inguinal ring or the lateral inguinal fossa–that’s what an indirect hernia does. Although it’s much more common for an indirect hernia to pass through the superficial inguinal ring, direct hernias could go through this ring too. However, the question is asking you to identify which region the hernia enters on the abdominal side, so superficial inguinal ring is not the correct answer. The supravesicular fossa is between the median and medial umbilical folds–it is formed where the peritoneum reflects from the anterior abdominal wall onto the bladder. Potentially, a very rare external supravesicular hernia could form here.
A patient presents with a hernia that is palpable at the superficial inguinal ring. Is this an indirect inguinal hernia?
Yes
No
There is insufficient evidence to tell
The correct answer is: There is insufficient evidence to tell.
You can’t tell if a hernia is direct or indirect just by palpating it! Although it is more common for indirect hernias to pass through the superficial inguinal ring while direct hernias usually stay in the inguinal canal, it is possible that a direct hernia could protrude through the superficial ring and even enter the scrotum.
In a female with an indirect inguinal hernia, the herniated mass lies along side of which structure as it traverses the inguinal canal?
Iliohypogastric nerve
Inferior epigastric artery
Ovarian artery and vein
Pectineal ligament
Round ligament of the uterus
The correct answer is: Round ligament of the uterus
In females, the round ligament of the uterus is the main structure traversing the inguinal canal. In males, the most important structure in the inguinal canal is the spermatic cord. The iliohypogastric nerve innervates the abdominal wall. It runs between the transversus abdominis and internal oblique muscles, then pierces the internal oblique at the anterior superior iliac spine to run between the internal and external obliques. The inferior epigastric artery lies between the peritoneum and the transversus abdominis, creating the lateral umbilical fold. The ovarian artery and vein are branches from the descending aorta and inferior vena cava which supply the ovary in the pelvis. The pectineal ligament is a thick layer of fascia over the pectineal line of the pubis. Although the pectineal ligament helps define the boundaries of the inguinal canal, you can’t really say that the pectineal ligament traverses the canal. That’s why the round ligament is the best answer.
The skin of the mons pubis is supplied by which nerve?
Anterior scrotal
Anterior labial
Femoral branch of the genitofemoral
Iliohypogastric nerve
Subcostal nerve
The correct answer is: Anterior labial
The anterior labial nerve (anterior scrotal in males) is the terminal branch of the ilioinguinal nerve. It innervates the skin of the mons pubis in females and the skin of the anterior scrotum in males. The femoral branch of the genitofemoral nerve provides sensory innervation to the upper medial thigh. The iliohypogastric nerve innervates muscles of the abdominal wall. The subcostal nerve is the ventral primary ramus of the twelfth thoracic nerve. It innervates muscles of the abdominal wall and skin of the lower abdominal wall.
While performing a routine digital examination of the inguinal region in a healthy teen-aged male, the physician felt a walnut-sized lump protruding from the superficial inguinal ring. She correctly concluded that it was :
definitely an indirect inguinal hernia
possibly an unusual femoral hernia
definitely a direct inguinal hernia
possibly an enlarged superficial inguinal lymph node
either a direct or an indirect inguinal hernia
The correct answer is: either a direct or indirect inguinal hernia
You can’t tell if an inguinal hernia is direct or indirect just by palpating it! Although indirect hernias are the ones that usually come out of the superficial inguinal ring and enter the scrotum, direct inguinal hernias might do this too! As for the other answers… a femoral hernia goes through the femoral ring into the femoral canal–it has nothing to do with the superficial inguinal ring. A superficial inguinal lymph node lies in the superficial fascia, parallel to the inguinal ligament. It would feel more superficial and should not be mistaken for a hernia protruding through the inguinal ring.
During your peer presentation of the inguinal region dissection, you would indicate the position of the deep inguinal ring to be:
Above the anterior superior iliac spine
Above the midpoint of the inguinal ligament
Above the pubic tubercle
In the supravesical fossa
Medial to the inferior epigastric artery
The correct answer is: Above the midpoint of the inguinal ligament
The deep inguinal ring is found near the midpoint of the inguinal ligament, below the anterior superior iliac spine. This ring is lateral to the inferior epigastric artery. The superficial inguinal ring is found above the pubic tubercle. Remember–the supravesical fossa is the space between the median and medial umbilical folds.
An elderly patient with a large indirect inguinal hernia came to your clinic complaining of pain in the scrotum. You conclude that the hernial sac is compressing the following nerve:
Femoral branch of the genitofemoral
Femoral
Iliohypogastric
Ilioinguinal
Subcostal
The correct answer is: Ilioinguinal nerve
The ilioinguinal nerve runs in the inguinal canal, so this nerve could easily be compressed by an inguinal hernia. The ilioinguinal nerve also gives off the anterior scrotal nerve, which is the nerve responsible for sensory innervation to the anterior scrotum. The location of this hernia and the scrotal pain both fit with an injury to the ilioinguinal nerve.
The femoral branch of the genitofemoral provides sensory innervation to the upper medial thigh. The femoral nerve innervates the anterior compartment of the thigh, and has some cutaneous sensory branches to the thigh. The iliohypogastric nerve innervates the skin of the lower abdominal wall, upper hip, and upper thigh. Finally, the subcostal nerve is the ventral primary ramus of T12, which innervates the skin of the anterolateral abdominal wall.
