Female Reproduction

Female Reproduction

Functions include providing viable gametes and an environment for fertilization and fetal development.

Ovary

Primary female reproductive organ, site of estrogen production and progesterone synthesis, produces/stores oocytes.

Follicle

Contains the ova and produces estrogen; grows in response to gonadotropin hormones.

Atresia

The process where a follicle will either die or ovulate.

Graafian follicle

The dominant follicle that can ovulate.

Corpus hemorrhagicum (CH)

Blood clot formed from a newly ruptured follicle.

Corpus luteum (CL)

Yellow structure formed from remaining tissue after a follicle has ovulated; a temporary endocrine gland producing progesterone.

Corpus albicans (CA)

Scar tissue left behind after CL regresses; avascular, nonfunctional tissue.

Oviduct

Passage from ovary to uterine horn with several functions including ovum and embryo transport, sperm storage and capacitation, site of fertilization, and early embryo development.

Infundibulum

Specialized end near ovary containing fimbriae, referred to as 'catcher's mitt'.

Ampulla

Part of the oviduct characterized by many mucosal folds.

Isthmus

Part of the oviduct that is directly connected to the uterus.

Uterus

Organ between oviducts and cervix; consists of a body and two horns, functions include maintenance of pregnancy, sperm transport, control of cyclity, embryonic and fetal development, maternal portion of placenta, and expulsion of fetus and fetal placenta.

Cervix

Connects uterus and vagina; site of semen deposit in swine, protects developing offspring by isolating the uterus from the external environment during pregnancy.

Vagina

Female copulatory organ that contains urethral opening, part of the birth canal, protects uterus from bacterial invasion, and connects cervix to external genitalia.

Vulva

External opening of reproductive system involved with recognition of receptivity and potentially produces female pheromones.

Broad ligament

Supports and suspends the reproductive tract; composed of several parts including mesovarium, mesosalpinx, and mesometrium.

Puberty

Age at which reproductive organs become functional and capable of adult reproductive function.

Estrous

Adjective pertaining to the cycle that contains estrus; a repetitive cycle that occurs when pregnancy does not occur.

Estrus

Noun referring to the period of time when a female is sexually receptive to a male (heat); a key event in the estrous cycle.

Proestrus

Follicular phase characterized by increasing estradiol and regressing CL causing progesterone to decrease.

Metestrus

Luteal phase where estrogen decreases, CL forms, and begins producing progesterone.

Diestrus

Luteal phase characterized by low estrogen and high progesterone; if no pregnancy occurs, ends with pulsatile release of PGF.

Estrous cycle phases

Include proestrus, estrus, metestrus, and diestrus.

Proestrus

The stage in the estrous cycle before estrus.

Estrus

The period of sexual receptivity in female mammals.

Metestrus

The stage in the estrous cycle following estrus.

Diestrus

The stage in the estrous cycle following metestrus.

Polyestrous

A type of estrous cycle where animals cycle continuously throughout the year.

Seasonal polyestrous

A type of estrous cycle where animals cycle during certain parts of the year.

Short day breeders

Animals that breed during the fall when days are shorter.

Long day breeders

Animals that breed during the spring when days are longer.

Signs of estrus

Indicators of female receptivity to males, including swollen vulva and mucous discharge.

Natural service

Breeding method where the male seeks out the female in estrus.

Artificial Insemination (AI)

A breeding method that involves human control of semen transfer without direct contact between male and female.

Gestation

The period of embryonic and fetal development before birth.

Embryonic development

The series of mitotic divisions that begins to differentiate the embryo.

Fetal development

The stage when the embryo begins to take shape and form of a young animal.

Recognition of pregnancy

Occurs approximately 12 days after fertilization.

Parturition

The process of giving birth, initiated by the fetus.

Active signs of parturition

Indicators such as the appearance of fetal membranes and expulsion of the fetus.

Lactation

The production and release of milk, stimulated by neuroendocrine reflexes.

Gonadotropins

Hormones that stimulate the ovaries.

Gonadotropin releasing hormone (GnRH)

Hormone that stimulates the production of FSH and LH.

Follicle stimulating hormone (FSH)

Hormone that stimulates all stages of follicle growth.

Lutenizing hormone (LH)

Hormone that stimulates the final growth of follicles and causes ovulation.

Prostaglandins

Hormones that directly control the reproductive state.

Progesterone (P4)

Hormone that maintains pregnancy and inhibits gonadotropin secretion.

Estrogen (17β-Estradiol, E2)

Hormone produced by growing follicles that prepares females for breeding and parturition.

Mammotropins

Hormones involved in lactation.

Prolactin (PRL)

Hormone that stimulates the production of milk.

Oxytocin (OXT)

Hormone that stimulates uterine contractions and milk excretion.