Why is the reproductive system not essential for individual survival
Because its primary role is ensuring species survival, not maintaining homeostasis in the individual
What are the main components of the reproductive system?
. Gonads (testes/ovaries), reproductive tracts (specialized ducts), accessory sex glands, and external genitalia
What are secondary sexual characteristics, and which hormones control them?
Traits distinguishing males from females (e.g., hips, beards, hair patterns). Estrogen drives female traits, testosterone drives male traits. Progesterone is not involved.
What is the role of meiosis in gametogenesis?
It reduces chromosome number by half, producing haploid gametes and ensuring genetic variation
Compare spermatogenesis and oogenesis.
- Spermatogenesis: Continuous from puberty, millions of sperm daily, each primary spermatocyte yields 4 viable sperm.
- Oogenesis: Begins in fetal life, cyclic from puberty, limited oocytes, each primary oocyte yields 1 ovum + 3 polar bodies.
When does oogenesis begin and end?
Begins during fetal life (meiotic arrest), resumes at puberty, and continues cyclically until menopause
How is genetic sex determined at conception?
By the sperm’s chromosome: XX = female, XY = male.
What role does the SRY gene play in differentiation
It codes for testis-determining factor (TDF), which directs gonads to form testes.
What happens if androgens are absent during development?
Female external genitalia and reproductive tract develop by default.
Name two disorders of sexual differentiation and explain them
- Testicular feminization syndrome: Genetic male develops female anatomy due to non-responsiveness to testosterone.
- Androgenital syndrome: Female fetus exposed to excess androgens develops male-like features
What are the two main functions of the testes?
Produce sperm (spermatogenesis) and secrete testosterone
Which cells produce testosterone in the testes
. Leydig (interstitial) cells between seminiferous tubules.
What are the main functions of Sertoli cells?
Nourish sperm, form blood-testis barrier, phagocytose waste, secrete fluid for sperm transport, secrete androgen-binding protein, release inhibin, and regulate spermatogenesis.
What condition occurs if testes fail to descend into the scrotum?
Cryptorchidism, which prevents viable sperm production.
What are the parts of a sperm cell and their functions
- Head: Contains DNA.
- Acrosome: Enzyme cap for ovum penetration.
- Midpiece: Mitochondria for energy.
- Tail: Provides motilit
List the five categories of testosterone effects
1) Reproductive system before birth, (2) sex-specific tissues after birth, (3) other reproductive effects, (4) secondary sexual characteristics, (5) non-reproductive actions (e.g., anabolic effects).
What roles does testosterone play during puberty?
Maturation of gonads, development of secondary sexual traits, libido, reproductive tract growth, and pubertal growth spurt.
What does the seminal vesicle contribute to semen?
Fructose (energy), prostaglandins (contractions), fibrinogen (clot formation
What is the contribution of the prostate gland?
Alkaline fluid (neutralizes vaginal acidity), clotting enzymes, and fibrinolysin
What do the bulbourethral glands secrete
Lubricating mucus for penetration
What are the phases of the male sexual response cycle?
Excitement (erection), plateau (intensifying arousal), orgasmic (ejaculation), and resolution (return to baseline
How does the female sexual response differ from males?
. Females have no ejaculation and no refractory period after orgasm
What are the main functions of the female reproductive system
Oogenesis, sperm reception, gamete transport, fertilization, gestation, placental formation, parturition, and lactation.
What is the function of the uterus?
Maintains the fetus during pregnancy and delivers it at birth.
