Module 28: Female Reproductive System

ovaries

female gonads - produce secondary oocytes and hormones, including progesterone and estrogens, inhibin, and relaxin.

uterine (Fallopian) tubes

transport a secondary oocyte to the uterus and normally are the sites where fertilization occurs.

uterus

site of implantation of an embryo, development of the fetus during pregnancy, and labor.

vagina

receives the penis during sexual intercourse and is the final passageway for childbirth.

mammary glands

synthesize, secrete, and eject milk for nourishment of the newborn.

ovarian ligament

ligament that anchors the ovaries to the uterus.

vulva (pudendum)

external genitals of the female

mons pubis

The rounded, fatty prominence over the pubic symphysis, covered by coarse pubic hair.

clitoris

An erectile organ of the female, located at the anterior junction of the labia minora, that is homologous to the male penis.

labia majora

Two longitudinal folds of skin extending downward and backward from the mons pubis of the female. They are homologous to the scrotum.

labia minora

Two small folds of mucous membrane lying medial to the labia majora of the female. Homologous to the spongy urethra.

myometrium

The smooth muscle layer of the uterus.

endometrium

The inner (mucous membrane) layer the uterus.

perimetrium

The outer (serosa) layer of the uterus.

fundus

The dome-shaped portion of the uterus superior to the uterine tubes.

cervix

Narrow portion of the uterus that opens to the vagina.

broad ligament

A double fold of parietal peritoneum attaching the uterus to the side of the pelvic cavity.

ovarian follicle

A general name for oocytes (immature ova) in any stage of development, along with their surrounding epithelial cells.

primordial follicle

earliest stage of an ovarian follicle.

mature follicle

A large, fluid-filled follicle containing a secondary oocyte and surrounding granulosa cells that secrete estrogens. Also called a Graafian follicle.

ovulation

The rupture of a mature ovarian (Graafian) follicle with discharge of a secondary oocyte into the pelvic cavity/Fallopian tube.

corpus luteum

A yellowish structure in the ovary formed when a follicle has discharged its secondary oocyte; secretes estrogens, progesterone, relaxin, and inhibin.

corpus albicans

A white fibrous patch in the ovary that forms after the corpus luteum degenerates.

Zona pellucida

Clear glycoprotein layer between a secondary oocyte and the surrounding corona radiata - required to initiate release of enzymes from the acrosome of the sperm.

Corona radiata

The innermost layer of granulosa cells that is firmly attached to the zona pellucida around a secondary oocyte.

ovum

The female reproductive or germ cell; an egg cell; arises through completion of meiosis in a secondary oocyte after penetration by a sperm.

diploid zygote

The single cell resulting from the union of male and female gametes; the fertilized ovum.

polar body

haploid cell formed during oogenesis which lacks the ability to be fertilized.

fimbriae

Fingerlike structures, especially the lateral ends of the uterine (fallopian) tubes.

oogenesis

Formation and development of female gametes (oocytes).

oogonia

diploid (2n) stem cells that divide mitotically to produce germ cells that have the potential to become primary oocytes.

secondary oocyte

cell stage that is ovulated from the mature ovarian (Graafian) follicle.

stratum functionalis

The layer of the endometrium that is shed during menstruation and that forms the maternal portion of the placenta during gestation.

stratum basalis

The layer of the endometrium that is maintained during menstruation and gestation and produces a new stratum functionalis following menstruation.

prolactin

hormone secreted by the anterior pituitary to stimulate milk production by mammary glands.

oxytocin

hormone produced by the hypothalamus, secreted by the posterior pituitary to stimulated milk ejection ("let down").

gonadotropin-releasing hormone (GnRH)

hormone secreted by the hypothalamus that stimulates the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) from the anterior pituitary.

follicle-stimulating hormone (FSH)

hormone secreted by the anterior pituitary that initiates follicular growth and further development of the ovarian follicles.

luteinizing hormone (LH)

hormone secreted by the anterior pituitary that triggers ovulation and then promotes formation of the corpus luteum.

estrogens

hormone promotes the development and maintenance of female reproductive structures, secondary sex characteristics, and the breasts; Increase protein anabolism, including the building of strong bones; stimulate proliferation of the stratum basalis to form a new stratum functionalis.

progesterone

secreted mainly by the corpus luteum, cooperates with estrogens to prepare and maintain the endometrium for implantation of a fertilized ovum and to prepare the mammary glands for milk secretion. High levels inhibit secretion of GnRH and LH.

relaxin

hormone produced by the ovaries and placenta that increases flexibility of the pubic symphysis and helps dilate the uterine cervix to ease delivery of a baby.

menstrual phase

discharge of blood, tissue fluid, mucus, and epithelial cells that usually lasts for 5 days; caused by a sudden reduction in estrogens and progesterone.

preovulatory phase

formation of the mature follicle; estrogen and inhibin from mature follicle decrease FSH; estrogen stimulates growth of stratum basalis.

fraternal (nonidentical) twins

codominant follicles ovulate and fertilized by different sperm (dizygotic).

maternal (identical) twins

single ovulated oocyte fertilized and embryo splits into two (monozygotic).

postovulatory phase

phase after ovulation when corpus luteum forms and secretes progesterone, estrogen, relaxin, and inhibin.

human chorionic gonadotropin (hCG)

hormone produced by the embryo and developing placenta that maintains the corpus luteum. Target of home pregnancy tests.

cleavage

initial mitosis of the embryo where cells divide but size of embryo doesn't change dramatically.

morula

stage of embryo 3-4 days after fertilization - a solid ball of stem cells.

blastocyst

stage of embryo 4.5-5 days after fertilization - a hollow ball of cells that implant in endometrium roughly day 6.