Human Reproduction Vocabulary Flashcards

Vocabulary terms and definitions covering male and female reproductive systems, gametogenesis, menstrual cycle, fertilization, pregnancy, and parturition from the lecture notes.

Reproduction

A biological process by which organisms produce offspring, ensuring the continuity of a species over generations.

Sexual Reproduction

A mode of reproduction involving the formation and fusion of male gametes (sperm) and female gametes (ova).

Viviparous

Organisms, such as humans, that give direct birth to young ones rather than laying eggs.

Sexual Dimorphism

Morphological differences between males and females of the same species that allow clear distinction between sexes.

Puberty

The age stage (typically 11 to 13 years in humans) when reproductive organs become functionally active and reproductive events begin.

Gametogenesis

The process of forming reproductive cells (gametes), termed spermatogenesis in males and oogenesis in females.

Insemination

The transfer of sperms into the female reproductive tract via the penis during sexual intercourse.

Fertilization

The fusion of a male gamete (sperm) and a female gamete (ova/secondary oocyte) to form a diploid zygote.

Cleavage

Continuous mitotic cell divisions of the zygote forming 2-cell, 4-cell, 8-cell, and 16-cell stages leading to a blastocyst.

Implantation

The attachment of the blastocyst to the endometrium layer of the uterine wall.

Gestation

The period of embryonic development during pregnancy, lasting approximately 9 months in human females.

Parturition

The process of delivery or expulsion of the fully developed fetus from the female uterus.

Lactation

The production and secretion of milk from mammary glands to feed the newborn baby.

Primary Sex Organs

Organs responsible for gamete production and sex hormone secretion, specifically testes in males and ovaries in females.

Secondary Sex Organs

Accessory structures including external genitalia, ducts, and glands that facilitate gamete transport, maturation, and reproduction.

Testis

The primary male sex organ located in the scrotum, responsible for producing sperms and male sex hormones.

Scrotum

A pouch of skin outside the male body containing the testes, maintaining a temperature $2\text{ to }2.5\text{ }^\frac{\text{o}}{\text{c}}$ lower than normal body temperature for sperm formation.

Testicular Compartments (Lobules)

Internal compartments inside each testis, numbering approximately 250 per testis.

Seminiferous Tubules

Highly coiled tubules (1 to 3 per testicular lobule) where sperms are produced.

Leydig Cells

Interstitial cells located between seminiferous tubules that synthesize and secrete male testicular hormones called androgens.

Androgens

Male sex hormones, including testosterone, produced by Leydig cells under the influence of Luteinizing Hormone (LH).

Sertoli Cells

Elongated nurse cells in seminiferous tubules that provide nutrition to developing germ cells and sperms.

Spermatogonia

Diploid male germ cells ($2n$) located on the inner wall of seminiferous tubules that divide to form sperms.

Spermiation

The release of mature sperms from Sertoli cells into the lumen of seminiferous tubules.

Seminal Plasma

The collective fluid secreted by male accessory glands (seminal vesicles, prostate gland, and bulbourethral glands), rich in fructose, calcium, and enzymes.

Semen

The fluid discharged during ejaculation, composed of sperms combined with seminal plasma.

Glans Penis

The enlarged distal end of the penis, covered by a loose fold of skin called foreskin or prepuce.

Ovary

The primary female sex organ located in the lower abdomen, responsible for producing female gametes and sex hormones.

Fallopian Tube (Oviduct)

A $10\text{ to }12\text{ cm}$ long tube consisting of the infundibulum, ampulla, and isthmus that connects the ovary to the uterus.

Ampulla

The wider middle region of the fallopian tube where fertilization of the secondary oocyte by a sperm takes place.

Fimbriae

Finger-like projections at the margin of the infundibulum that help collect the secondary oocyte from the ovary during ovulation.

Endometrium

The inner glandular layer of the uterus that undergoes cyclical breakdown and renewal during the menstrual cycle and receives the implanted blastocyst.

Myometrium

The thick middle smooth muscle layer of the uterus that exhibits strong contractions during labor and parturition.

Birth Canal

The canal formed by the cervical canal together with the vagina through which the fetus passes during delivery.

Vulva

The collective term for female external genitalia, comprising the mons pubis, labia majora, labia minora, clitoris, and hymen.

Mons Pubis

A cushion of fatty tissue covered by skin and pubic hair located in the upper region of female external genitalia.

Clitoris

A small, erectile finger-like structure present at the upper junction of the labia minora above the urethral opening.

Hymen

A vascular partial membrane that partially covers the opening of the vagina.

Mammary Alveoli

Clusters of secretory cells within mammary lobules that synthesize milk under the influence of prolactin.

Colostrum

The yellowish milk secreted by mammary glands during the initial few days of lactation, rich in IgA antibodies for infant immunity.

Spermatogenesis

The process of forming haploid sperms ($n$) from diploid spermatogonia ($2n$) starting at puberty.

Spermiogenesis

The maturation process where non-motile haploid spermatids transform into motile spermatozoa (sperms).

Acrosome

An anterior cap-like structure on the head of a sperm filled with hydrolytic enzymes necessary for penetrating outer egg layers.

Oogenesis

The process of forming a mature female gamete (ova), initiated during embryonic development and completed upon fertilization.

Antrum

A fluid-filled cavity characteristic of tertiary and Graafian follicles in the ovary.

Graafian Follicle

The fully mature ovarian follicle containing a secondary oocyte surrounded by the zona pellucida, ready for ovulation.

Ovulation

The release of the secondary oocyte due to the rupture of the Graafian follicle triggered by an LH surge around the 14th day of the cycle.

Corpus Luteum

A yellow glandular structure formed from the remnants of the ruptured Graafian follicle under LH influence that secretes progesterone and estrogen.

Menarche

The first occurrence of menstruation in human females during puberty.

Menopause

The permanent cessation of menstrual cycles in human females, typically occurring around 45 to 50 years of age.

LH Surge

The rapid peak level of Luteinizing Hormone (LH) mid-cycle (around day 14) that induces the rupture of the Graafian follicle.

Fast Block Method

Rapid membrane depolarization of the secondary oocyte upon initial sperm contact to temporarily prevent entry of additional sperms.

Slow Block Method

The release of cortical granules that hardens the zona pellucida, permanently preventing entry of multiple sperms (polyspermy).

Blastocyst

An embryonic development stage featuring an outer trophoblast layer, an inner cell mass, and a central blastocoel cavity.

Placenta

A structural and functional unit formed between maternal uterine tissue and fetal chorionic villi for nutrient, gas, and waste exchange.

Foetal Ejection Reflex

Mild uterine contractions induced by the fully developed fetus and placenta that trigger maternal oxytocin release to initiate labor.