Human Reproduction, Development, and Reproductive Technologies

Comprehensive vocabulary flashcards covering male and female reproductive anatomy, gametogenesis, the ovarian and uterine cycles, endocrine regulation, gestation, parturition, lactation, and contraception.

Seminiferous tubules

Tightly coiled tubules located inside testicular lobules (2 to 3 per lobule) lined with germinal epithelium where sperm cells are formed by meiosis.

Cells of Leydig

Endocrine cells situated in the connective tissue between seminiferous tubules that secrete the male sex hormone testosterone.

Epididymis

A convoluted tubule measuring approximately $5\,\text{cm}$ in length where sperm are stored for several months and undergo maturation.

Vas deferens

A muscular sperm duct that extends from the epididymis behind the urinary bladder, enlarges into an ampulla, and joins the seminal vesicle duct to form the ejaculatory duct.

Seminal vesicles

Accessory glands that produce an alkaline fluid containing fructose, providing energy and promoting motility for sperm cells.

Prostate gland

An accessory gland that secretes an alkaline fluid to neutralize vaginal acidity, provides energy for sperm, and supplies activating enzymes.

Cowper's gland

Bulbourethral accessory gland that secretes mucus to lubricate the end of the penis.

Acrosome

A specialized cap-like lysosome on the head of a sperm cell that contains proteolytic enzymes used to penetrate the outer layers of the ovum.

Spermatogenesis

The meiotic process occurring within the germinal epithelium of the seminiferous tubules that produces haploid spermatozoa from diploid precursor cells.

Oogenesis

The process of meiosis occurring in the ovarian follicles that produces mature haploid ova.

Graafian follicle

A fluid-filled mature ovarian follicle containing a developing oocyte that secretes oestrogen and ruptures at ovulation.

Ovulation

The release of a mature ovum from a ruptured Graafian follicle in the ovary, typically occurring on day 14 of the menstrual cycle in response to an LH surge.

Corpus luteum

A glandular structure formed from the remnants of a ruptured Graafian follicle after ovulation that secretes progesterone and oestrogen to maintain the endometrium.

Fallopian tubes

Ciliated muscular tubes extending from the ovaries to the uterus that serve as the site of fertilisation and convey the ovum or zygote toward the uterine cavity.

Endometrium

The vascular internal mucosal lining of the uterus that thickens to support blastocyst implantation and is shed during menstruation if fertilisation does not take place.

Myometrium

The thick middle layer of smooth, involuntary muscle in the uterine wall that contracts during childbirth to expel the fetus.

Follicle-stimulating hormone (FSH)

A gonadotrophic hormone released by the anterior pituitary gland that stimulates follicle growth in females and stimulates spermatogenesis in males.

Luteinizing hormone (LH)

A pituitary hormone that induces ovulation and corpus luteum formation in females, and stimulates testosterone secretion by the cells of Leydig in males.

Human chorionic gonadotropin (hCG)

A hormone produced by the blastocyst and early placenta that preserves the corpus luteum, sustaining progesterone secretion and preventing menstruation.

Implantation

The attachment and embedding of the blastocyst into the endometrial wall of the uterus, typically occurring around days 8 to 9 following fertilisation.

Amnion

The inner extra-embryonic membrane surrounding the embryo that holds amniotic fluid to absorb mechanical shock, enable movement, and prevent dehydration.

Chorion

The outermost extra-embryonic membrane that develops vascular chorionic villi that penetrate the maternal endometrium to form the placenta.

Placenta

A temporary organ connecting the fetus to maternal blood via chorionic villi, facilitating diffusion of gases, nutrients, and wastes without mixing maternal and fetal blood.

Umbilical cord

A connective stalk linking the fetus to the placenta containing two umbilical arteries transporting deoxygenated fetal blood and one umbilical vein transporting oxygenated blood.

Oxytocin

A hormone secreted by the pituitary gland that drives uterine contractions during labor via a positive feedback loop and induces milk ejection during breastfeeding.

Prolactin

An anterior pituitary hormone that stimulates milk synthesis within the mammary glands after childbirth.

Relaxin

A hormone active during pregnancy that loosens pelvic ligaments, widens the birth canal, and suppresses premature uterine contractions.

Intrauterine device (IUD)

A small T-shaped or coiled copper device placed inside the uterine cavity by a healthcare provider to alter the endometrium and prevent blastocyst implantation for $5\text{--}10\,\text{years}$.

Vasectomy

A surgical, permanent contraceptive method for males in which the sperm ducts (vasa deferentia) are cut and tied, leaving semen free of sperm cells.

Tubal ligation

A surgical, permanent female sterilization procedure where the oviducts are severed and tied off to stop sperm from reaching ovulated eggs.

In vitro fertilisation (IVF)

An assisted reproductive procedure where mature eggs extracted from the ovaries are fertilised with sperm outside the body in culture dishes before embryo transfer into the uterus.

Fetal alcohol syndrome (FAS)

A developmental disorder caused by maternal alcohol consumption during pregnancy, producing distinctive cranial features such as a low nasal bridge, epicanthal folds, indistinct philtrum, micrognathia, and a thin upper lip.

Identical twins

Monozygotic twins formed when a single egg fertilised by one sperm divides into two separate embryonic structures, commonly sharing a single placenta.

Fraternal twins

Dizygotic twins formed when two distinct ova are released and fertilised by two distinct sperm cells, each developing with its own placenta and amniotic sac.