Reproductive System & Embryology - VOCABULARY Flashcards

Vocabulary flashcards covering key terms from the lecture notes on the reproductive system and embryology.

Gonads

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

Gametogenesis

Process of forming human sex cells (gametes); includes oogenesis in females and spermatogenesis in males.

Oocyte

Female gamete; develops in the ovary and becomes the ovum after fertilization.

Sperm

Male gamete; produced in large numbers by the testes; fertilizes the oocyte.

Oogenesis

Maturation of the female gamete (oogonia to oocytes) with meiosis; begins before birth and continues cyclically after puberty.

Spermatogenesis

Production of sperm in the testes; begins at puberty and includes meiosis and spermiogenesis.

Meiosis

Two-step cell division producing haploid gametes; includes crossing over and genetic variation.

Diploid (2n)

Cells with two complete sets of chromosomes.

Haploid (n)

Cells with a single set of chromosomes (gametes).

Gametogenesis vs. Mitosis

Gametogenesis makes gametes (haploid); mitosis makes identical diploid body cells.

Primordial Follicle

Most primitive ovarian follicle with a primary oocyte and a single flattened layer of follicle cells.

Primary Follicle

Ovarian follicle with a primary oocyte and multiple layers of granulosa cells.

Secondary Follicle

Follicle with a primary oocyte, several granulosa layers, and a fluid-filled space (antrum).

Vesicular (Graafian) Follicle

Mature follicle with a large antrum that releases the secondary oocyte during ovulation.

Corpus Luteum

Remnant of the follicle after ovulation; secretes progesterone and estrogen to support the uterus.

Corpus Albicans

White scar form of a regressed corpus luteum.

Ovarian Cycle

Monthly maturation of ovarian follicles; phases: follicular, ovulation, and luteal.

Follicular Phase

Ovarian phase of follicle growth and rising estrogen; ~days 1–13.

Ovulation

Release of the secondary oocyte from the mature follicle; LH surge triggers it.

Luteal Phase

Formation of the corpus luteum; secretion of progesterone and estrogen; days 15–28.

Gonadotropin-Releasing Hormone (GnRH)

Hypothalamic hormone that stimulates the anterior pituitary to release FSH and LH.

Follicle-Stimulating Hormone (FSH)

Stimulates follicle growth and estrogen production; part of the ovarian cycle regulation.

Luteinizing Hormone (LH)

Triggers ovulation and stimulates the corpus luteum to secrete hormones.

Estrogen

Sex hormone produced by developing follicles; promotes secondary sexual characteristics and endometrial growth; regulated by FSH/LH.

Progesterone

Hormone produced by the corpus luteum; prepares and maintains the uterine lining for implantation.

Inhibin

Hormone that inhibits FSH secretion; helps regulate follicle recruitment.

Gonadotropins

Hormones (FSH and LH) from the pituitary that regulate the gonads.

Hypothalamus–Pituitary–Gonadal Axis

Hormonal system involving GnRH, FSH, LH, and sex hormones controlling puberty and reproduction.

Gametogenesis vs. Embryogenesis

Gametogenesis forms gametes; embryogenesis forms the embryo after fertilization.

Fertilization

Fusion of sperm and oocyte to form a zygote; occurs in the ampulla of the uterine tube.

Capacitation

Physiologic conditioning of sperm in the female tract enabling fertilization.

Acrosome Reaction

Sperm releases enzymes to penetrate the zona pellucida of the oocyte.

Zona Pellucida

Glycoprotein layer surrounding the oocyte; prevents polyspermy after fertilization.

Corona Radiata

Outer layer of cumulus cells surrounding the oocyte.

Zygote

Diploid cell formed by the fusion of sperm and oocyte; first cell of a new individual.

Cleavage

Series of mitotic divisions of the zygote that increases cell number without increasing overall size.

Morula

Solid ball of cells (16-cell stage) formed during early embryogenesis.

Blastocyst

Hollow ball with an inner cell mass and trophoblast; implants into the uterine lining.

Trophoblast

Outer layer of the blastocyst that contributes to placental formation.

Embryoblast

Inner cell mass that becomes the embryo proper.

Bilaminar Germinal Disc

Two-layer embryonic disc formed by the epiblast and hypoblast.

Hypoblast

Germ layer that contributes to the yolk sac and lines the blastocyst cavity.

Epiblast

Germ layer that gives rise to all three primary germ layers.

Amnion

Membrane that forms the amniotic cavity and surrounds the embryo, producing amniotic fluid.

Yolk Sac

First extraembryonic membrane; initial site of blood cell formation and important early nutrition.

Chorion

Outermost extraembryonic membrane; forms part of the placenta with maternal tissue.

Placenta

Highly vascular organ enabling maternal-fetal exchange and hormone production.

Chorionic Villi

Fingerlike projections of the chorion containing fetal vessels; sites of nutrient/gas exchange.

Gastrulation

Process forming the three primary germ layers: ectoderm, mesoderm, endoderm; occurs in week 3.

Ectoderm

Outer germ layer; forms skin, nervous system, and related structures.

Mesoderm

Middle germ layer; forms muscles, bones, circulatory system, kidneys, gonads, and more.

Endoderm

Innermost germ layer; forms the GI and respiratory tracts and associated organs.

Neurulation

Formation of the neural tube from the ectoderm; foundation of the CNS.

Organogenesis

Formation of organs; begins after germ layers form and folding completes.

Teratogen

Substance causing birth defects or developmental abnormalities (e.g., alcohol, certain drugs, viruses).

Amniotic Fluid

Fluid within the amniotic cavity that cushions and protects the fetus.

Placental Hormones

Estrogen, progesterone, hCG, placental lactogen, CRH, relaxin, and others produced by the placenta to support pregnancy.

hCG

Human chorionic gonadotropin; maintains the corpus luteum in early pregnancy and is used in pregnancy tests.

CRH

Corticotropin-releasing hormone; placental hormone involved in timing of birth and fluid balance.

Pregnancy Trimester

Pregnancy divided into three periods: first, second, and third trimesters.

Endometriosis

Condition where endometrial-like tissue grows outside the uterus; can cause pain and infertility.

Lactation

Production and secretion of breast milk by the mammary glands; stimulated by prolactin and oxytocin.

Colostrum

Early milk produced at end of pregnancy and just after birth; rich in antibodies (IgA).

Prolactin

Hormone from the anterior pituitary that stimulates milk production.

Oxytocin

Hormone from the posterior pituitary that stimulates milk ejection and uterine contractions.

Ductus Deferens

Muscular tube transporting sperm from the epididymis toward the urethra.

Seminal Vesicles

Glands that secrete alkaline fluid with fructose and prostaglandins to nourish and aid sperm.

Prostate Gland

Gland producing seminal fluid rich in nutrients and PSA; contributes to semen.

Bulbourethral Glands

Glands secreting mucus to lubricate and protect the urethra during intercourse.

Sertoli Cells (Sustentacular Cells)

Supportive cells in testes that nourish developing sperm and produce inhibin.

Blood–Testis Barrier

Barrier formed by tight junctions between Sertoli cells protecting sperm from immune attack.

Interstit ial (Leydig) Cells

Cells in the testes that produce androgens (testosterone) in response to LH.

ABP (Androgen-Binding Protein)

Protein secreted by Sertoli cells that binds testosterone to maintain high intratesticular testosterone.

Inhibin (FSH Regulation)

Hormone that inhibits FSH secretion, regulating spermatogenesis.

Sperm Anatomy

Sperm structure includes head (with DNA), midpiece (mitochondria), and tail (flagellum) plus acrosome.

Mother–Fetus Blood Separation

Maternal and fetal blood exchange occurs in placenta without mixing blood.

Cervical Cancer & HPV

Cervical cancer risk linked to HPV infection; HPV vaccines prevent common types.

Labor (Parturition)

Process of delivering the fetus and placenta; driven by estrogen, oxytocin, and prostaglandins.

Prostaglandins in Labor

Lipids that stimulate uterine contractions and cervical dilation during labor.