••• Chapter 54^ Infertility^547
❍ What is the process of sperm development and maturation?
Each day about 3 million spermatogonia begin to develop into primary spermatocytes.
Spermatocytes complete first meiotic division to become secondary spermatocytes.
Secondary spermatocytes complete second meiotic division to become spermatids.
Spermatids undergo maturation process to spermatozoa (mature sperm).
Final maturation step takes place in female genital tract, process called capacitation.
Entire process takes 70 days, and every day 50% of the potential sperm are lost.
❍ How long does it take for spermatozoa to travel from the testes to the ejaculatory ducts?
2 to 3 weeks, semen analysis reflects conditions that occurred weeks earlier. For example, febrile illness results in
transient but dramatic drop in sperm concentration.
❍ What testicular cells are analogous to the theca cells of the ovary?
Leydig cells that produce testosterone and are located in the testicular interstitium.
❍ What testicular cells are analogous to the granulosa cells of the ovary?
Sertoli cells are located in the seminiferous tubules and form the blood-testes barrier as well as provide metabolic
support to the developing sperm by concentrating testosterone in the tubules
❍ What is the function of FSH in the testicle?
Increases LH receptors on the Leydig cells, inhibin from the Sertoli cells, and inhibits FSH secretion through a
negative feedback mechanism.
❍ What is the function of LH in the testicle?
Increases testosterone production by the Leydig cells. Testosterone and estradiol produce a negative feedback
mechanism to the hypothalamus and pituitary resulting in decreased LH production.
❍ When should a male infertility evaluation be initiated?
After 1 year of regular intercourse without success but may be initiated earlier if the female partner is >35 years of
age or the man has a concerning history of mumps, cryptorchidism, trauma, diabetes, inguinal hernia repair, or
is taking medication that could cause ejaculatory dysfunction such as alpha-blockers, phentolamine, methyldopa,
guanethidine, and reserpine.
❍ How should a semen specimen be collected and analyzed?
Collect after 3 days of abstinence and examine specimen within 1 hour of collection, best to give specimen at
the lab.
❍ What are the major parameters of semen analysis?
Concentration.
Motility.
Morphology.