Question

For each case of reduced fertility A–E, select the most appropriate option from the following list of aspects of the male and female reproductive systems. 

1. Ovulation. 

2. Spermatogenesis. 

3. Transport in the uterine tube. 

4. Transport in the vas deferens. 

5. Erection of the penis. 

6. Ejaculation. 

7. Implantation.

 A. A couple’s infertility is attributed to medication with a drug which interferes with relaxation of vascular smooth muscle in the reproductive system. 

B. Contraception is provided by a combination of oestrogen and progesterone given for 21 consecutive days in each month. 

C. Contraception is provided by an intrauterine device. 

D. A couple’s infertility is attributed to the man’s wearing a tight-fitting garment which holds the testes close to the trunk. 

E. Infertility is attributed to surgery which has damaged sympathetic nerves in the pelvis.

Answer 1

A. Option 5 Erection of the penis. Erection depends on relaxation of smooth muscle in arterioles supplying the erectile tissue of the penis; its failure is described as impotence, in which condition ejaculation is not possible. 

B. Option 1 Ovulation. The contraceptive pill leads to feedback inhibition of release of the gonadotrophins follicle-stimulating hormone and luteinizing hormone which control maturation and release of the ovum. 

C. Option 7 Implantation. The intrauterine device interferes with implantation of the fertilized ovum. 

D. Option 2 Spermatogenesis. This type of garment can raise the testicular temperature to a level where spermatogenesis is considerably impaired, leading to reduced fertility. 

E. Option 6 Ejaculation. Ejaculation depends on sympathetic nerves for expulsion of seminal fluid into the urethra, and also for contraction of the bladder neck to prevent retrograde ejaculation into the bladder.