Female Repro Part 1

Female reproductive physiology

Study of the physiological processes of the female reproductive system, including the ovary, folliculogenesis, oogenesis, steroidogenesis, puberty, reproductive cycle, ovulation, corpus luteum, gestation, and parturition.

Ovary

Anatomical structure responsible for oogenesis and steroidogenesis.

Fallopian tube

Anatomical structure that serves as the site of fertilization.

Uterus

Anatomical structure that serves as the site of implantation.

Vagina

Anatomical structure that serves as the site of semen deposition in certain animals.

Vestibule

Anatomical structure whose secretions are important for lubrication during copulation.

Vulva

Copulatory organ.

Cortex

Functional part of the ovary that contains follicles and corpus luteum.

Medulla

Part of the ovary that contains blood vessels.

Types of ovarian follicles

Primary, growing, mature (Graafian), and atretic (degenerating) follicles.

Primary follicle

Type of ovarian follicle included among the stages of folliculogenesis.

Growing follicle

Type of ovarian follicle that develops toward the mature follicle.

Mature (Graafian) follicle

Fully developed ovarian follicle associated with ovulation.

Atretic follicle

Degenerating ovarian follicle.

Corpus hemorrhagicum

Hemorrhage in the antrum of the ovulated follicle.

Corpus luteum

Structure characterized by the presence of lutein cells that secrete progesterone.

Lutein cells

Cells of the corpus luteum responsible for secreting progesterone.

Folliculogenesis

Formation of a mature or Graafian follicle during the follicular phase of the estrous cycle.

Follicular phase

Phase of the estrous cycle during which folliculogenesis occurs.

Types of follicles in folliculogenesis

Primary follicle, secondary follicle, growing follicle, and mature follicle.

Parts of follicles

Theca externa, theca interna, basement membrane, granulosa, antrum, cumulus oophorus, corona radiata, zona pellucida, perivitelline membrane, vitelline membrane, vitellus, nucleus, polar body, and hillock.

Theca externa

Outer part of the follicle listed as one of its structural parts.

Theca interna

Part of the follicle listed among its structural components.

Basement membrane

Structural part of the follicle separating the follicular components.

Granulosa

Cellular layer of the follicle shown surrounding the oocyte.

Antrum

Fluid-filled space within a developing follicle.

Cumulus oophorus

Cellular structure associated with the oocyte within the follicle.

Corona radiata

Layer associated with the oocyte and listed as a part of the follicle.

Zona pellucida

Structure surrounding the oocyte.

Perivitelline membrane

Membrane listed as one of the parts associated with the oocyte.

Vitelline membrane

Membrane listed as one of the follicle/oocyte structures.

Vitellus

Yolk listed as one of the structures associated with the follicle.

Nucleus

Structure of the oocyte listed among the parts of the follicle.

Polar body

Structure associated with oogenesis and listed among the follicle components.

Hillock

Structure listed among the parts of follicles.

Monotocous animals

Animals in which, during each estrous cycle, one follicle rapidly develops more than the others and only one ovum is released when it ruptures.

Polytocous animals

Animals in which several follicles develop and rupture at the same time.

Oogenesis

Process shown involving oogonia, primary oocytes, secondary oocytes, polar bodies, and the ovum.

Oogones

Starting germ cells shown in the oogenesis sequence.

Primary oocyte

Diploid (2n) cell shown in the oogenesis sequence before formation of the secondary oocyte and first polar body.

Secondary oocyte

Haploid (n) cell produced in the oogenesis sequence along with the first polar body.

First polar body

Haploid (n) product formed together with the secondary oocyte.

Second polar body

Haploid (n) product formed during the later stage of the oogenesis sequence.

Ovum

Haploid (n) cell shown as the final product in the oogenesis sequence.

Steroidogenesis

Process involving the production of reproductive steroid hormones.

Pregnanes

Steroidogenesis group associated with progesterone production.

Progesterone

Hormone produced by the corpus luteum and placenta.

Functions of progesterone

Endometrial growth, inhibition of uterine contraction during pregnancy, and regulation of GnRH secretion.

Estradiol

One of the estrogens listed in the module.

Estrone

One of the estrogens listed in the module.

Estriol

One of the estrogens listed in the module.

Functions of estradiol, estrone, and estriol

Development of the Müllerian duct, hyperemia and hypertrophy of endometrium, development of secondary sexual characteristics, growth hormone of the reproductive tract, migration of leukocytes into the uterine lumen, initiation of uterine tone, epitheliotrophic effects, and changes in vaginal epithelium.

Müllerian duct

Structure whose development is promoted by estradiol, estrone, and estriol.

Hyperemia and hypertrophy of endometrium

Changes in the endometrium associated with estrogen action.

Secondary sexual characteristics

Characteristics whose development is promoted by estradiol, estrone, and estriol.

“Growth hormone of reproductive tract”

Description given for estrogen in the module.

Migration of leukocytes into uterine lumen

Effect of estradiol, estrone, and estriol.

Uterine tone

Effect initiated by estradiol, estrone, and estriol.

“Epitheliotrophic” hormone

Description given for estrogen.

Vaginal epithelium

Structure that undergoes changes in response to estradiol, estrone, and estriol.

Mammary gland development

Function of estradiol, estrone, and estriol.

Enlargement of external genitalia

Function of estradiol, estrone, and estriol.

Steroidogenesis and gametogenesis

Processes promoted by estradiol, estrone, and estriol.

Anabolic effects of estrogen

Effects involving bone and muscle growth.

Hormonal control of female reproduction

The regulatory system involving the hypothalamus, GnRH, anterior pituitary, FSH, LH, granulosa cells, theca cells, inhibin, and ovarian estrogens.

GnRH

Gonadotropin-releasing hormone shown as released from the hypothalamus and acting through the portal circulation on the anterior pituitary.

Anterior pituitary

Gland stimulated by GnRH to release FSH and LH.

FSH

Hormone released by the anterior pituitary that acts on granulosa cells.

LH

Hormone released by the anterior pituitary that acts on theca cells and is mainly involved in the positive feedback response before ovulation.

Granulosa cells

Ovarian cells stimulated by FSH and involved in estrogen production and inhibin secretion.

Theca cells

Ovarian cells stimulated by LH and involved in androgen production.

Androgens

Hormones produced by theca cells and used in the ovarian pathway toward estrogen production.

Inhibin

Hormone produced by granulosa cells and shown as part of the hormonal feedback system.

Positive feedback mode

Mode occurring right before the ovulatory phase in which estrogen provides positive feedback on GnRH release and mainly on LH release.

Puberty

Onset of reproductive capacity when the female gonads become capable of releasing gametes.

GnRH at puberty

At puberty onset, GnRH increases.

Estrogen at puberty

At puberty onset, estrogen secretion gradually increases.

Factors affecting puberty

Breed, climate, season, and sex.

Breed effect on puberty

Smaller breeds generally reach puberty at an earlier age.

Climate effect on puberty

Puberty occurs earlier in the tropics.

Seasonal effect on puberty

Sheep/ewe are short-day breeders, while horses are long-day breeders.

Sex effect on puberty

Females reach puberty earlier than males.

Bitch puberty

9–16 months.

Queen puberty

8–13 months.

Sow puberty

6–7 months.

Cow puberty

9–11 months.

Mare puberty

12–24 months.

Ewe puberty

6–7 months.

Doe puberty

4–8 months.

Reproductive cycle

Recurring reproductive process in females that includes the estrous and menstrual cycles.

Two types of reproductive cycle

Estrous cycle and menstrual cycle.

Estrous cycle

Rhythmic sexual behavior pattern that develops in female mammals during puberty and is characterized by regular but limited periods of sexual receptivity (estrus).

Estrus

Period of sexual receptivity.

Follicular phase

Phase of the reproductive cycle consisting of proestrus and estrus.

Proestrus

Part of the follicular phase characterized by follicular growth.

Estrus in the follicular phase

Period of sexual receptivity during which ovulation occurs due to an LH surge except in the cow.

Cow ovulation

Occurs during metestrus rather than during estrus.

Luteal phase

Phase of the reproductive cycle consisting of metestrus, diestrus, and anestrus.

Metestrus

Post-ovulatory phase and period of early corpus luteum development.

Diestrus

Period of maximal corpus luteum development.