Human Reproductive System – Male & Female (Gametogenesis and Hormonal Control)

Vocabulary flashcards covering major structures, processes, and hormones of the male and female reproductive systems, including gametogenesis and hormonal regulation.

Sexual Reproduction

Process in which male and female gametes fuse to form a zygote.

Gametes

Sex cells (sperm or ova) carrying half the normal chromosome number (23 in humans).

Zygote

Fertilised egg formed by fusion of sperm and ovum.

Gonads

Primary sex organs that produce gametes and hormones (testes in males, ovaries in females).

Primary Sex Organs

The gonads, essential for gamete production.

Secondary Sex Organs

Additional reproductive structures required for reproduction (ducts, glands, external genitalia).

Testes

Paired male gonads that produce sperm and testosterone; located in the scrotum.

Scrotum

Skin-covered pouch divided into two sacs that holds the testes outside the body for cooler temperature.

Seminiferous Tubules

Fine tubules within testicular lobules where spermatogenesis occurs.

Spermatogonia

Diploid stem cells lining seminiferous tubules; divide by mitosis to maintain sperm supply.

Primary Spermatocyte

Enlarged diploid cell that begins meiosis I to form secondary spermatocytes.

Secondary Spermatocyte

Haploid cell produced after meiosis I; undergoes meiosis II to form spermatids.

Spermatid

Immature haploid cell resulting from meiosis II; matures into spermatozoon.

Spermatozoon (Sperm)

Mature male gamete consisting of head, mid-piece, and tail.

Acrosome

Cap on sperm head containing enzymes to penetrate the ovum’s coatings.

Epididymis

Highly coiled duct on posterior testis where sperm mature and are stored (~1 month).

Vas Deferens

Muscular sperm duct transporting sperm from epididymis toward urethra.

Semen

Mixture of sperm and seminal fluid that nourishes and transports sperm.

Seminal Vesicles

Glands behind bladder producing sugar-rich fluid; contribute ~60 % of semen volume.

Prostate Gland

Single doughnut-shaped gland producing thin, milky alkaline fluid for semen.

Bulbourethral (Cowper’s) Glands

Pair of pea-sized glands secreting mucus that lubricates urethra and neutralises acidity.

Urethra (Male)

Common duct for urine and semen (not simultaneously) exiting via penis.

Penis

Male copulatory organ containing erectile tissue that becomes engorged during arousal.

Erectile Tissue

Spongy connective tissue with rich blood supply enabling penile erection.

Ovaries

Female gonads that produce ova, oestrogen, and progesterone; almond-shaped, inside pelvic cavity.

Oocyte

Immature female gamete within an ovarian follicle.

Follicle

Structure of germ cell plus surrounding cells within the ovary; nourishes developing oocyte.

Primary Follicle

Dormant follicle containing a primary oocyte formed before birth.

Secondary Follicle

Developing follicle with fluid cavity; contains a secondary oocyte.

Graafian (Mature) Follicle

Enlarged pre-ovulatory follicle that bulges from ovary surface.

Corpus Luteum

Yellow body formed from ruptured follicle after ovulation; secretes progesterone and oestrogen.

Corpus Albicans

Scar tissue remnant of a degenerated corpus luteum when fertilisation does not occur.

Uterine (Fallopian) Tubes

Ciliated tubes transporting ovum from ovary to uterus; usual site of fertilisation.

Fimbriae

Finger-like projections at distal uterine tube guiding ovulated oocyte into the tube.

Uterus

Hollow muscular organ (womb) where embryo implants and develops.

Endometrium

Highly vascular lining of uterus that thickens each cycle and is shed during menstruation.

Cervix

Narrow neck of uterus opening into vagina; pathway for sperm and barrier during pregnancy.

Vagina

Elastic muscular canal receiving penis and serving as birth canal.

Vulva

External female genital region including labia and clitoris.

Labia Majora

Outer fleshy folds with pubic hair and sebaceous glands.

Labia Minora

Inner skin folds surrounding vaginal and urethral openings; upper ends surround clitoris.

Clitoris

Erectile organ rich in nerves; provides sexual pleasure when stimulated.

Gametogenesis

Overall process of producing gametes by meiosis (spermatogenesis or oogenesis).

Spermatogenesis

Meiotic process in testes that forms spermatozoa from spermatogonia.

Oogenesis

Meiotic process in ovaries that forms a single ovum and polar bodies from oogonia.

Polar Bodies

Small haploid cells produced during oogenesis that generally degenerate.

Zona Pellucida

Glycoprotein layer surrounding ovum; binds sperm and triggers acrosome reaction.

Corona Radiata

Outer layer of follicle cells surrounding ovum after ovulation; provides nutrients.

Endocrine Glands

Organs that secrete hormones directly into the bloodstream.

Hormone

Chemical messenger produced by an endocrine gland and transported in blood to target cells.

GnRH (Gonadotrophin-Releasing Hormone)

Hypothalamic hormone stimulating anterior pituitary release of FSH and LH.

FSH (Follicle-Stimulating Hormone)

Pituitary hormone that stimulates sperm production in testes and follicle development in ovaries.

LH (Luteinising Hormone)

Pituitary hormone that triggers testosterone production in males and ovulation/corpus luteum formation in females.

Testosterone

Male sex hormone promoting spermatogenesis and secondary sexual characteristics.

Inhibin

Hormone from testes that provides negative feedback to reduce FSH secretion.

Oestrogen

Female hormone from follicles/corpus luteum causing endometrial growth and secondary sexual traits.

Progesterone

Hormone from corpus luteum preparing and maintaining endometrium for implantation.

Negative Feedback

Regulatory mechanism where rising hormone levels inhibit further hormone release.

Ovarian Cycle

Monthly events in an ovary: follicular phase, ovulation, luteal phase.

Follicular Phase

Pre-ovulation period (days 1-12) of follicle growth and oestrogen production.

Ovulation

Release of secondary oocyte from mature follicle around day 14 of cycle.

Luteal Phase

Post-ovulation period (days 15-28) dominated by corpus luteum and progesterone secretion.

Menstrual Cycle

Changes in endometrium of non-pregnant uterus averaging 28 days, controlled by hormones.