Question

Vas differentia receives a duct from A and opens into the B as the ejaculatory duct. A and B in the above statement is
(a) A- Vasdeferens B-Urinary bladder
(b) A-Seminal vesicle B-Urethra
(c) A-Urethra B-Seminal vesicle
(d) A- Urethra B-Urinary bladder

Answer 1

Hint: Passage of sperms in humans starts from seminal vesicles. In males, the common passage for both urine and sperms is the urethra located at the bottom of the urinary bladder.

Complete answer:
In males, the urethra is the common terminal duct for both the reproductive and excretory systems. Seminiferous tubules in the testes open into vasa efferentia through rete testis. This vasa efferentia opens into vas deferens through the epididymis. Vas deferens comes out as an ejaculatory duct that opens into the urethra. The neck of the urinary bladder also leads into the urethra which has internal and external urethral sphincters.

Additional information:
- In the excretory system of humans, nephrons in the kidneys open into the renal pelvis. The outer surface of the kidney consists of a deep notch called hilum from where the renal artery enters and renal veins and ureter exit the kidney.
- Ureter that comes from the renal pelvis through the hilum opens into the urinary bladder.
- The neck of the urinary bladder leads into the urethra which contains the internal urethral sphincter and external urethral sphincter.
- In the male reproductive system of humans, the testis contains Seminiferous tubules in the testes open into vasefferentia through rete testis. This vasa efferentia opens into vas deferens through the epididymis. Vas deferens comes out as an ejaculatory duct that opens into the urethra.

So, the correct answer is ‘A-Seminal vesicle B-Urethra’

Note:
-The internal urethral sphincter present in the urethra is made up of smooth muscles so it is involuntary whereas the external urethral sphincter present in the urethra is made up of striped muscles so it is voluntary.
-The urethra opens near the vaginal orifice in females and through the penis in males.