Biology Multiple Choice Questions on “The Male External Genitalia”.
1. What do the Leydig cells secrete?
a) B cells
b) Semen
c) Sperms
d) Androgen
Answer: d
Clarification: The areas on the exterior of the seminiferous tubules called interstitial spaces, contain small blood vessels and small clusters of big, polygonal cells called Leydig cells or interstitial cells. Leydig cells synthesize and secrete hormones (testicular) called androgens.
2. The growth, maintenance and functioning of secondary sex organs is maintained by the ____
a) leydig cells
b) seminal vesicles
c) posterior pituitary gland
d) testosterone
Answer: a
Clarification: The growth, maintenance and functioning of secondary sex organs (epididymis, vasa deferentia, accessory glands and penis) are under the control of testosterone hormone secreted by Leydig’s cells of testis, while those of seminiferous tubules and Leydig’s cells are controlled by Follicle Stimulating Hormone (FSH) and Interstitial Cells Stimulating Hormone (ICSH) of anterior pituitary lobe respectively.
3. Where does the vas deferens emerge from?
a) Cauda epididymis
b) Caput epididymis
c) Corset epididymis
d) Corpus epididymis
Answer: a
Clarification: A 40cm long vas deferens emerges from the cauda epididymis on each side and leaves the scrotal sac and enters the abdominal cavity through the inguinal canal.
4. Why does the end of the vas deferens dilate?
a) To enter the inguinal canal
b) For temporary storage of sperms
c) To enter the urinary bladder
d) For support
Answer: b
Clarification: The vas deferens loops over the urinary bladder where it is joined by duct from the seminal vesicle to form the ejaculatory duct. The end of the vas deferens dilates to form a spindle-like ampulla for temporary storage of sperm.
5. The free end of vas deferentia bears?
a) Ciliated cells
b) Pseudostratified columnar epithelium
c) Stereocilia
d) Leydig cells
Answer: c
Clarification: The vas deferens is lined with pseudostratified columnar epithelium. The free end of its cells also bears stereocilia. The muscular wall of the vas deferens is formed of smooth muscles, and the latter’s peristaltic contractions propel the sperms through the vas deferens
6. External opening of the urethra is called _______
a) penile urethra
b) pubic symphysis
c) prostatic urethra
d) urethral meatus
Answer: d
Clarification: External opening of the urethra is called urethral meatus. The male urethra provides a common pathway for the flow of urine called semen. It is much longer in male than in the female, measuring about 15-29 cm.
7. Prosthetic urethra carries urine and semen.
a) True
b) False
Answer: b
Clarification: The urethra includes three parts. The first part is surrounded by the prostate gland and is called the prostatic urethra which arises from the urinary bladder and carries urine only.
8. What is the second part of the urethra called?
a) Prosthetic urethra
b) Membranous urethra
c) Penile urethra
d) Urethral meatus
Answer: b
Clarification: The second part is the membranous urethra which is situated behind the lower part of the pubic symphysis. The membranous urethra is the smallest urethra.
9. Tip of the glans penis is called _______
a) ventral corpus spongiosum
b) dorsal corpora cavernosa
c) aperture
d) urinogenital aperture
Answer: d
Clarification: The penis is male genitalia (male copulatory organ). At the tip of the glans penis is the slit like opening called the external urethral orifice or urinogenital aperture.
10. The penis contains four cylindrical masses of erectile tissue.
a) False
b) True
Answer: a
Clarification: The penis contains three cylindrical masses of erectile tissue—two dorsal corpora cavernosa and one ventral corpus spongiosum. These bodies are surrounded by fibrous tissue.