1. Male Reproductive System
The main parts are:
Testes (two balls in scrotum): Produce sperm (male gametes) and testosterone (male hormone).
Temperature in scrotum is 2-3°C lower than body for sperm production.
Epididymis: Stores and matures sperm.
Vas deferens: Tube that carries sperm from testes.
Seminal vesicles, Prostate gland, Bulbourethral glands: Add fluids to sperm to make semen
(nourishes and protects sperm).
Penis: Delivers semen into female body during sex.
Accessory ducts: Vas deferens → Ejaculatory duct → Urethra.
2. Female Reproductive System
The main parts are:
Ovaries (two): Produce eggs (ova) and hormones – estrogen and progesterone.
Fallopian tubes (oviducts): Place where sperm meets egg (fertilization happens here).
Uterus (womb): Where baby grows during pregnancy.
Cervix: Lower part of uterus.
Vagina: Birth canal, receives penis during sex.
Accessory parts: Mammary glands (breasts) for milk production after birth.
3. Gametogenesis (Formation of Gametes)
Spermatogenesis (in testes): Starts at puberty, continuous process.
One spermatogonium → 4 sperm.
Sperm has head (with nucleus), middle piece (energy), tail (for swimming).
Controlled by FSH, LH, and testosterone.
Oogenesis (in ovaries): Starts before birth, stops and restarts at puberty.
One oogonium → 1 egg + 3 polar bodies (polar bodies degenerate).
Only one egg released per month.
Egg is large, non-motile.
Humans are heterogametic in males (XY chromosomes → sperm can have X or Y).
4. Menstrual Cycle (Only in Females)
Starts at puberty (menarche ~12-13 years), ends at ~45-50 years (menopause).
Average 28 days cycle.
Phases:
Menstrual phase (Day 1-5): Uterus lining sheds → bleeding (periods).
Follicular phase (Day 6-13): FSH hormone makes follicle (with egg) grow in ovary. Estrogen
thickens uterus lining.
Ovulation (Day 14): LH hormone surge → mature egg released from ovary.
Luteal phase (Day 15-28): Empty follicle becomes corpus luteum → secretes progesterone
(maintains uterus lining for pregnancy).
If no pregnancy → corpus luteum breaks → lining sheds → next cycle.
(No cycle during pregnancy.)
The main parts are:
Testes (two balls in scrotum): Produce sperm (male gametes) and testosterone (male hormone).
Temperature in scrotum is 2-3°C lower than body for sperm production.
Epididymis: Stores and matures sperm.
Vas deferens: Tube that carries sperm from testes.
Seminal vesicles, Prostate gland, Bulbourethral glands: Add fluids to sperm to make semen
(nourishes and protects sperm).
Penis: Delivers semen into female body during sex.
Accessory ducts: Vas deferens → Ejaculatory duct → Urethra.
2. Female Reproductive System
The main parts are:
Ovaries (two): Produce eggs (ova) and hormones – estrogen and progesterone.
Fallopian tubes (oviducts): Place where sperm meets egg (fertilization happens here).
Uterus (womb): Where baby grows during pregnancy.
Cervix: Lower part of uterus.
Vagina: Birth canal, receives penis during sex.
Accessory parts: Mammary glands (breasts) for milk production after birth.
3. Gametogenesis (Formation of Gametes)
Spermatogenesis (in testes): Starts at puberty, continuous process.
One spermatogonium → 4 sperm.
Sperm has head (with nucleus), middle piece (energy), tail (for swimming).
Controlled by FSH, LH, and testosterone.
Oogenesis (in ovaries): Starts before birth, stops and restarts at puberty.
One oogonium → 1 egg + 3 polar bodies (polar bodies degenerate).
Only one egg released per month.
Egg is large, non-motile.
Humans are heterogametic in males (XY chromosomes → sperm can have X or Y).
4. Menstrual Cycle (Only in Females)
Starts at puberty (menarche ~12-13 years), ends at ~45-50 years (menopause).
Average 28 days cycle.
Phases:
Menstrual phase (Day 1-5): Uterus lining sheds → bleeding (periods).
Follicular phase (Day 6-13): FSH hormone makes follicle (with egg) grow in ovary. Estrogen
thickens uterus lining.
Ovulation (Day 14): LH hormone surge → mature egg released from ovary.
Luteal phase (Day 15-28): Empty follicle becomes corpus luteum → secretes progesterone
(maintains uterus lining for pregnancy).
If no pregnancy → corpus luteum breaks → lining sheds → next cycle.
(No cycle during pregnancy.)
