Reproductive Biology Terms

A collection of flashcards defining key terms related to reproductive biology.

asexual reproduction

The generation of offspring from a single parent that occurs without the fusion of gametes.

blastocoel

The fluid-filled cavity that forms in the center of a blastula.

blastula

A hollow ball of cells that marks the end of the cleavage stage during early embryonic development in animals.

cervix

The neck of the uterus, which opens into the vagina.

cleavage

The process of cytokinesis in animal cells characterized by pinching of the plasma membrane.

clitoris

An organ at the upper intersection of the labia minora that engorges with blood and becomes erect during sexual arousal.

cloaca

A common opening for the digestive, urinary, and reproductive tracts found in many nonmammalian vertebrates.

conception

The fertilization of an egg by a sperm in humans.

contraception

The deliberate prevention of pregnancy.

corpus luteum

A secreting tissue in the ovary that forms from the collapsed follicle after ovulation and produces progesterone.

ectoderm

The outermost of the three primary germ layers in animal embryos.

egg

The female gamete.

ejaculation

The propulsion of sperm from the epididymis through the muscular vas deferens, ejaculatory duct, and urethra.

ejaculatory duct

The section of the ejaculatory route formed by the convergence of the vas deferens and a duct from the seminal vesicle.

endoderm

The innermost of the three primary germ layers in animal embryos.

endometrium

The inner lining of the uterus, which is richly supplied with blood vessels.

epididymis

A coiled tubule located adjacent to the mammalian testis where sperm are stored.

estradiol

A steroid hormone that stimulates the development and maintenance of the female reproductive system.

estrous cycle

A reproductive cycle characteristic of female mammals in which sexual response occurs only during a mid-cycle point known as estrus.

fertilization

The union of haploid gametes to produce a diploid zygote.

fetus

A developing mammal that has all the major structures of an adult.

follicle

A microscopic structure in the ovary that contains the developing oocyte and secretes estrogens.

follicle-stimulating hormone (FSH)

A tropic hormone produced by the anterior pituitary that stimulates the production of eggs and sperm.

gametogenesis

The process by which gametes are produced.

gastrula

An embryonic stage in animal development encompassing the formation of three layers: ectoderm, mesoderm, and endoderm.

gastrulation

A series of cell and tissue movements in which the blastula-stage embryo folds inward.

gestation

Pregnancy; the condition of carrying one or more embryos in the uterus.

glans

The rounded head of the penis or of the clitoris in humans.

gonad

The male or female gamete-producing organ.

hermaphroditism

A condition in which an individual has both female and male gonads.

hymen

A thin membrane that partly covers the vaginal opening in the human female.

in vitro fertilization (IVF)

Fertilization of oocytes in laboratory containers followed by artificial implantation in the uterus.

labia majora

A pair of thick, fatty ridges that enclose and protect the vulva.

labia minora

A pair of slender skin folds that surround the openings of the vagina and urethra.

Leydig cell

A cell that produces testosterone and other androgens located between seminiferous tubules.

luteinizing hormone

A tropic hormone produced by the anterior pituitary that stimulates ovulation in females.

mammary gland

An exocrine gland that secretes milk to nourish the young.

menopause

The cessation of ovulation and menstruation.

menstrual cycle

The periodic growth and shedding of the uterine lining that occurs in the absence of pregnancy.

menstruation

The shedding of portions of the endometrium during a uterine cycle.

mesoderm

The middle primary germ layer in a triploblastic animal embryo.

morphogenesis

The development of the form of an organism and its structures.

oocyte

A cell in the female reproductive system that differentiates to form an egg.

oogenesis

The process in the ovary that results in the production of female gametes.

organogenesis

The process in which organ rudiments develop from the three germ layers.

ovarian cycle

The cyclic recurrence of the follicular phase, ovulation, and the luteal phase in the mammalian ovary.

ovary

The structure that produces female gametes and reproductive hormones.

oviduct

A tube from the ovary to the vagina or uterus.

ovulation

The release of an egg from an ovary.

parthenogenesis

A form of asexual reproduction in which females produce offspring from unfertilized eggs.

penis

The copulatory structure of male mammals.

placenta

A structure in the pregnant uterus for nourishing a viviparous fetus.

progesterone

A steroid hormone that stimulates the development and maintenance of the female reproductive system.

prostate gland

A gland in human males that secretes an acid-neutralizing component of semen.

scrotum

A pouch of skin that houses the testes.

semen

The fluid that is ejaculated by the male during orgasm.

seminal vesicles

A gland in males that secretes a fluid component of semen.

seminiferous tubule

A highly coiled tube in the testis where sperm are produced.

Sertoli cell

A support cell of the seminiferous tubule that surrounds and nourishes developing sperm.

sexual reproduction

Reproduction arising from the fusion of two gametes.

sperm

The male gamete.

spermatogenesis

The continuous production of mature sperm cells in the testis.

testis

The male reproductive organ in which sperm and reproductive hormones are produced.

testosterone

A steroid hormone required for the development of the male reproductive system.

tropic hormone

A hormone that acts on endocrine tissues to trigger the release of other hormones.

urethra

A tube that releases urine and, in males, also serves as the exit tube for the reproductive system.

uterine cycle

The cyclic changes in the endometrium that occur in the absence of pregnancy.

uterus

A female organ where eggs are fertilized and development of the young occurs.

vagina

Part of the female reproductive system between the uterus and the outside opening.

vas deferens

The tube in the male reproductive system in which sperm travel from the epididymis to the urethra.

vulva

Collective term for the female external genitalia.

zygote

The diploid cell produced by the union of haploid gametes during fertilization.