Human Reproduction – Key Vocabulary

A comprehensive set of vocabulary flashcards covering the major structures, processes, hormones, and events of human reproduction as discussed in the lecture.

Reproduction

Biological process by which organisms produce offspring to ensure species continuity.

Sexual Reproduction

Type of reproduction involving formation and fusion of male and female gametes.

Viviparous

Organisms that give birth to live young instead of laying eggs (e.g., humans).

Sexual Dimorphism

Distinct difference in appearance between male and female individuals of a species.

Puberty

Developmental stage when gametogenesis and secondary sexual characteristics begin.

Gametogenesis

General term for the formation of gametes (spermatogenesis in males, oogenesis in females).

Spermatogenesis

Process of sperm formation from spermatogonia in the testes, starting at puberty and continuing throughout life.

Oogenesis

Formation of ova in the ovary, beginning during foetal life and completing only after fertilisation.

Primary Sex Organs

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

Secondary Sex Organs

Structures that support gamete transport, fertilisation, and development (e.g., ducts, glands, uterus, vagina).

Accessory Ducts (Male)

Vas efferentia, epididymis, vas deferens, ejaculatory duct, urethra – transport and store sperm.

Accessory Glands (Male)

Seminal vesicles, prostate gland, bulbourethral glands; add secretions to form semen.

Scrotum

Pouch outside the abdominal cavity that houses testes and maintains temperature 2–2.5 °C below body temp.

Penis

External male copulatory organ that delivers semen into the female reproductive tract.

Testis

Male primary sex organ; produces sperm and androgens.

Seminiferous Tubules

Highly coiled structures in testicular lobules where spermatogenesis occurs.

Sertoli Cells

Nurse cells in seminiferous tubules that provide nutrition and secrete Sperm Maturation Factor.

Leydig Cells

Interstitial cells between seminiferous tubules that secrete male sex hormones (androgens).

Epididymis

6 m long coiled duct on posterior testis; site of sperm maturation and temporary storage.

Vas Deferens

Duct transporting sperm from epididymis to ejaculatory duct; loops over urinary bladder.

Ejaculatory Duct

Formed by union of vas deferens and duct of seminal vesicle; opens into urethra.

Urethra (Male)

Shared terminal duct for urinary and reproductive systems in males (uro-genital duct).

Seminal Vesicle

Paired gland producing fructose-rich seminal plasma (60–70 % of semen).

Prostate Gland

Single gland below bladder adding calcium and enzymes to semen (25–30 %).

Bulbourethral (Cowper’s) Gland

Paired glands producing mucus for lubrication of urethra and penis.

Semen

Mixture of spermatozoa and seminal plasma; pH 7.2-7.5, 2.5-5 ml per ejaculation.

Spermiogenesis

Transformation of spermatids into mature spermatozoa.

Spermiation

Release of mature sperm into lumen of seminiferous tubules.

Acrosome

Cap-like structure on sperm head containing enzymes for penetration of ovum.

Middle Piece (Sperm)

Region rich in mitochondria providing ATP for motility.

Capacitation

Functional maturation of sperm in female tract that enhances motility and prepares acrosome reaction.

Acrosomal Reaction

Release of acrosomal enzymes (hyaluronidase, CPE, ZP lysin) to penetrate ovum’s layers.

Syngamy

Fusion of male and female pronuclei forming diploid zygote.

Morula

Solid ball of 8–16 blastomeres formed after cleavage of zygote.

Blastocyst

Early embryo with trophoblast outer layer, inner cell mass, and blastocoel.

Trophoblast

Outer layer of blastocyst that forms part of placenta and mediates implantation.

Inner Cell Mass (ICM)

Group of cells within blastocyst that forms the embryo proper (pluripotent stem cells).

Implantation

Embedding of blastocyst into uterine endometrium about 6–7 days after fertilisation.

Gastrulation

Developmental process forming three germ layers: ectoderm, mesoderm, endoderm.

Placenta

Temporary organ formed from maternal endometrium and fetal chorion for nutrient, gas, and waste exchange.

Umbilical Cord

Connection between fetus and placenta containing blood vessels for exchange.

hCG (Human Chorionic Gonadotropin)

Placental hormone maintaining corpus luteum; basis of pregnancy tests.

hPL (Human Placental Lactogen)

Placental hormone promoting maternal milk gland preparation and fetal growth.

Relaxin

Placental hormone that relaxes ligaments and widens pubic symphysis for childbirth.

Gestation

Period of fetal development in uterus; ~9 months in humans, divided into three trimesters.

Parturition

Process of childbirth triggered by foetal ejection reflex and oxytocin-mediated uterine contractions.

Lactation

Production and secretion of milk from mammary glands after childbirth.

Colostrum

First yellowish milk rich in antibodies crucial for neonatal immunity.

Menstrual Cycle

Cyclic changes in ovaries and uterus (~28 days) in human females.

Menarche

Onset of first menstrual cycle at puberty.

Menopause

Permanent cessation of menstrual cycles, typically around 50 years of age.

Follicular (Proliferative) Phase

Pre-ovulatory phase with follicle growth and endometrial regeneration; rising FSH, LH, estrogen.

Ovulation

Release of secondary oocyte from Graafian follicle around mid-cycle (LH surge).

Luteal (Secretory) Phase

Post-ovulatory phase with corpus luteum secreting progesterone to maintain endometrium.

LH Surge

Sharp mid-cycle rise in luteinising hormone that triggers ovulation.

Corpus Luteum

Yellow endocrine body formed from ruptured follicle; secretes progesterone and some estrogen.

FSH (Follicle Stimulating Hormone)

Anterior pituitary hormone stimulating gametogenesis and follicular development.

LH (Luteinising Hormone)

Pituitary hormone stimulating Leydig cells in males and ovulation/corpus luteum formation in females.

GnRH (Gonadotropin-Releasing Hormone)

Hypothalamic hormone regulating release of FSH and LH from anterior pituitary.

Estrogen

Ovarian steroid promoting follicular growth, secondary sexual traits, and endometrial proliferation.

Progesterone

Ovarian hormone from corpus luteum maintaining endometrium and pregnancy.

Graafian Follicle

Mature ovarian follicle with large antrum containing secondary oocyte ready for ovulation.

Zona Pellucida

Glycoprotein coat around oocyte that mediates sperm binding and blocks polyspermy.

Corona Radiata

Layer of follicular cells surrounding zona pellucida of ovulated secondary oocyte.

Ampullary-Isthmic Junction

Specific site in fallopian tube where fertilisation typically occurs.

Fimbriae

Finger-like projections at infundibulum that sweep ovulated oocyte into oviduct.

Oestrus Cycle

Reproductive cycle in non-primate mammals, counterpart of menstrual cycle.