Q-1 A 62-year-old man is incapable of penile erection after rectal surgery with prostatectomy. The patient most likely has a lesion of which of the following nerves?
a. Perineal nerve
b. Hypogastric nerve
c. Sacral splanchnic nerve
d. Pelvic splanchnic nerve
Ans-1: (d) Pelvic splanchnic nerve
Ref:Read the text below
Sol:
· The pelvic splanchnic nerve contains preganglionic parasympathetic fibers, whereas the sacral splanchnic nerve contains preganglionic sympathetic fibers.
· Parasympathetic fibers are responsible for erection, whereas sympathetic fibers are involved with ejaculation.
· The right and left hypogastric nerves contain primarily sympathetic fibers and visceral sensory fibers.
· The dorsal nerve of the penis and the perineal nerve provide sensory nerve fibers.
Q-2 Which of the following nerves are intimately related to the humerus and are most likely to be injured by upper humerus fracture?
a. Axillary and musculocutaneous
b. Radial and ulnar
c. Radial and axillary
d. Median and musculocutaneous
Ans-2: (c) Radial and axillary
Ref:Read the text below
Sol:
· The axillary nerve passes posteriorly around the surgical neck of the humerus, and the radial nerve lies in the radial groove of the middle of the shaft of the humerus.
· The ulnar nerve passes behind the medial epicondyle, and the median nerve is vulnerable to injury by supracondylar fracture of the humerus, but these nerves lie close to or in contact with the lower portion of the humerus.
· The musculocutaneous nerve is not in direct contact with the humerus.
Q-3 Which of the following intrinsic muscles of the thumb is most likely injured in Bennett's fracture?
a. Abductor pollicis brevis
b. Flexor pollicis brevis (superficial head)
c. Opponens pollicis
d. Adductor pollicis
Ans-3: (c) Opponens pollicis
Ref:Read the text below
Sol:
· The opponens pollicis inserts on the first metacarpal.
· All other intrinsic muscles of the thumb, including the abductor pollicis brevis, the flexor pollicis brevis, and the adductor pollicis muscles, insert on the proximal phalanges.
Q-4 During pelvic surgery, injury to the genitofemoral nerve would result in sensory loss in which of the following locations:
a. Mons and upper labia majora
b. Anterior vulva and anterior thigh
c. Lateral perineum and labia majora
d. Buttocks and contiguous perineum
Ans-4: (b) Anterior vulva and anterior thigh
Ref:Novak’s Gynecology 12th -86
Sol:
§ The genitofemoral nerve arises from the nerve roots L1 and L2 and follows a course through the pelvis over the psoas muscle and ultimately splits into two branches – the genital branch, which enters the inguinal ring to the anterior vulva, and the femoral branch, which intervates a portion of the skin of the anterior and medial thigh.
Q-5 Complete transaction of the presacral nerve is difficult because the nerve :
a. Overlies the middle sacral vessels and is usually composed of two or three incompletely fused trunks
b. Is a subsidiary of the celiac plexus and is located along the inferior mesenteric artery
c. Is part of the ovarian plexus, which transverses the infundubulopelvic ligament
d. Is Frankenhauser’s ganglion, which also innervates the uterus and vagina.
Ans-5: (a) Overlies the middle sacral vessels and is usually composed of two or three incompletely fused trunks
Ref:Novak’s Gynecology 12th -89
Sol:
§ The presacral neurectomy is an operation in which the superior hypogastric plexus is divided and resected in order to interrupt sensory fibers from the uterus and cervix, and has been associated with relief of dysmenorrheal secondary to endometriosis in about 50 to 75% of cases.
§ Because there are several branches and their locations vary, and because other nerves supply these structures, the resection of these nerves does not uniformly relieve the pain.
Q-6 Septum transversum gives rise to all of the following except
a. Lesser omentum
b. Coronary ligament
c. Ligament teres hepatitis
d. Falciparum ligament
Ans-6: (b) Coronary ligament
Ref: Gray’s anatomy 40th ed pg 1168
Sol:
· The coronary ligament is formed by the reflection of the peritoneum from the diaphragm onto the posterior surfaces of the right lobe of the liver
Q-7 Structure not developing in mesentry of stomach
a. Liver
b. Kidney
c. Pancreas
d. Spleen
Ans-7: (b) Kidney
Ref: Langman's Medical Embryology 10th ed pg 222,212,215
Sol:
About Mesentry
· Portions of the gut tube and its derivatives are suspended from the dorsal and ventral body wall by mesenteries, double layers of peritoneum that enclose an organ and connect it to the body wall.
· Such organs are called intraperitoneal, whereas organs that lie against the posterior body wall and are covered by peritoneum on their anterior surface only (e.g., the kidneys) are considered retroperitoneal.
· Peritoneal ligaments are double layers of peritoneum (mesenteries) that pass from one organ to another or from an organ to the body wall. Mesenteries and ligaments provide pathways for vessels, nerves, and lymphatics to and from abdominal viscera
· Initially the foregut, midgut, and hindgut are in broad contact with the mesenchyme of the posterior abdominal wall.
· By the fifth week, however, the connecting tissue bridge has narrowed, and the caudal part of the foregut, the midgut, and a major part of the hindgut are suspended from the abdominal wall by the dorsal mesentery, which extends from the lower end of the esophagus to the cloacal region of the hindgut.
· In the region of the stomach, it forms the dorsal mesogastrium or greater omentum; in the region of the duodenum, it forms the dorsal mesoduodenum; and in the region of the colon, it forms the dorsal mesocolon. Dorsal mesentery of the jejunal and ileal loops forms the mesentery proper.
· Ventral mesentery, which exists only in the region of the terminal part of the esophagus, the stomach, and the upper part of the duodenum, is derived from the septum transversum.
About Pancreas
· The pancreas is formed by two buds, dorsal and ventral, originating from the endodermal lining of the duodenum.
· Whereas the dorsal pancreatic bud is in the dorsal mesentery, the ventral pancreatic bud is close to the bile duct
About Liver
· Growth of the liver into the mesenchyme of the septum transversum divides the ventral mesentery into (a) the lesser omentum, extending from the lower portion of the esophagus, the stomach, and the upper portion of the duodenum to the liver and (b) the falciform ligament, extending from the liver to the ventral body wall in the fifth week of development, the spleen primordium appears as a mesodermal proliferation between the two leaves of the dorsal mesogastrium.
About Spleen
· With continued rotation of the stomach, the dorsal mesogastrium lengthens, and the portion between the spleen and dorsal midline swings to the left and fuses with the peritoneum of the posterior abdominal wall.
Q-43 After prolonged treatment the following drugs should be gradually withdrawn, except
a. Clonidine
b. Corticosteroids
c. Thiazide diuretics
d. Alpha methyldopa
Ans-43: (c) Thiazide diuretics
Ref: Read the text below.
Sol:
§ Thiazides need not be withdrawn gradually.
§ Antihypertensives like clonidine and α methyl dopa may cause rebound hypertension on abrupt withdrawal.
§ Corticosteroids may cause acute adrenal crisis on sudden stoppage of the treatment.
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