The Reproductive System Part 2: The Female Reproductive System

These flashcards cover key concepts of the female reproductive system, hormonal cycles, and physiological changes involved in reproduction.

What are the 6 main components of the female reproductive tract?

Ovaries, oviducts, uterus (uterine horns & uterine body), cervix, vagina, and vulva.

Traditionally in the U.S., what is a “spay” and what anatomy is involved?

A spay is an ovariohysterectomy and involves surgically removing the ovary and uterine horns.,

What are the broad ligaments?

Paired, broad sheets of connective tissue that suspend the ovaries, oviducts, and uterus from the dorsal abdominal wall. These prevent the reproductive tract from moving all over the place when the animal is running, etc.

What is the suspensory ligament of the ovary?

A thin, white, rubberband-like tissue that is attached to the caudal pole of the kidney and last rib on one end, and attached to the cranial pole of the ovary at the other end.

What is the clinical significance of the suspensory ligament?

It often needs to be stretched, torn, or cut to get the ovary “out” of the abdomen enough to tie off (ligate) the ovarian blood vessels. Otherwise, it wants to spring the ovary back into the abdomen and makes for a difficult surgery without stretching or cutting it.

What is the proper ligament of the ovary?

A ligament that connects an ovary to the lateral surface of the uterine horn. It is short, tough, and wide.

What is the clinical significance of the proper ligament of the ovary?

It is often clamped with an instrument then used to move the ovary in various directions (with better leverage and no slippage) during a spay.

What is the primary function of the ovaries?

To produce haploid gametes (ova) and hormones.

What is the process called by which ova are produced?

Oogenesis.

What happens to the oocytes at birth?

At birth, the ovaries have tens of thousands of oocytes, and no new oocytes are produced after that point. They don’t complete oogenesis (meiosis) until the right time (puberty/sexually mature).

Where does oogenesis occur in the female?

In the ovary — within a blister-like structure called a follicle.

What are the two groups of hormones the ovaries produce?

Estrogens and progestins.

What is the role of estrogens during the reproductive cycle?

They prepare the animal for breeding and getting pregnant by causing physical and behavioral changes that support receptiveness (growth of mammary glands, increase in oviduct secretions, sexual receptivity, and proliferation of keratinized cells lining the vaginal canal.

What is the function of progestins?

To prepare the uterus for implantation and maintaining pregnancy.
They cause physical and behavioral changes that maximize the probabilty of the embryo developing safely; stimulate mammary gland growth, and progestins also stimulate certain secretions

What is the oviduct also known as?

Uterine tube or fallopian tube. This small (barely visible to the nake eye) tube is the most proximal segment of the uterine horns and extends all the way to the ovary (but not touching it).

What is the infundibulum?

The funnel-shaped end of the oviduct that captures the ovum during ovulation.

The fingerlike projections at the end of the oviduct (the infundibulum) are known as __________________________.

Fimbrae.

What occurs during fertilization?

The head of a spermatozoon enters the ovum, merging their nuclei and chromosomes to create a zygote.

What is the structure and function of the uterus?

A muscular organ where the zygote implants and develops into a fetus, also plays a role in expelling the fetus during birth.

What is the cervix's function?

To act as a valve that seals off the uterus from the vagina.

The “act” of a spermatozoon entering the ovum and making it diploid is known as what?

Fertilization

What two structures discussed in lecture(s) have a more-or-less “Y” shape. Hint: One is macroscopic, the other is mircoscopic and considered part of Immunity & Defense.

The uterus (uterine horns and uterine body) of mammals and the antibodies prudced by plasma cells.

What sphincter muscle is located between the vaginal cavity and the body of the uterus (b/t the non-sterile and usually sterile portion of the reproductive tract)?

The cervix.

What is the ovarian cycle?

A series of changes in the ovary that lead to the release of an ovum, occurring in a cyclic fashion.

What begins the ovarian cycle?

Puberty (sexual maturity) and is initiated by the pituitary gland secreting enough FSH.

What does FSH released by the anterior pituitary gland do?

Stimulates the growth and development of the follicle in the ovary, which in turn starts to produce more and more estrogens as it enlarges.

What is a primary follicle?

A waiting/resting stage of the follicle present in newborns.

What causes a mature follicle to finally rupture and release and ovum?

A surge of luteininzing hormone (LH) released by the pituitary gland.

What is a Mature Graafian follicle?

A mature follicle that is ready for ovulation.

What is the corpus luteum?

A yellow body that forms from the follicle after ovulation and helps maintain pregnancy by releasing hormones called progestins.

What happens if fertilization does not occur?

The corpus luteum degenerates, leading to a decrease in hormone levels and the start of menstruation in humans.

A. What does the word “estrus” refer to?

B. Is there another word that is synonymous with estrus?

A) A time period when the female is receptive to the male for breeding with specific physical and behavioral changes to her body.

B) Being in “heat” is another way of saying the animal is in the estrus stage or is simply “in estrus”.

What is the Estrous Cycle?

A time period with several stages reflective of the entire ovarian cycle and may include up to five time periods known as proestrus, estrus, metestrus, diestrus, and anestrus. Sometimes defined as the time from “estrus to (the next) estrus” which would cover all the periods mentioned here.

What does a monoestrous cycle mean?

An animal has one cycle per year (estrus to estrus).

What does diestrous mean?

An animal has two cycles per year.

What characterizes a seasonally polyestrous animal?

They cycle continuously during certain seasons of the year (e.g. Spring).

What is the mnemonic PEMDA related to?

The order of stages in the estrous cycle: proestrus, estrus, metestrus, diestrus, anestrus.

What happens in the proestrus stage?

Development and growth of follicles; thickening of the uterine and vaginal lining.

What occurs during estrus?

Ovulation typically occurs, and the female is maximally receptive to mating.

What animal is said to skip metestrus (the period is so short that it’s not noticeable)?

Dogs, as they transition quickly to diestrus (after estrus).

What defines the diestrus stage?

The corpus luteum reaches maximum size, and if implantation doesn’t occur, it degenerates.

What happens during anestrus?

The ovary is inactive and shuts down for a period. This stage is behaviorally and physically the complete opposite of estrus.

What is pseudopregnancy in canines?

An abnormally long and extended diestrus where the dog acts pregnant without being so. She may “nest build” and even lactate! This usually spontaneously resolves within a few weeks without medical intervention or may need hormonal intervention or even spaying (to remove the majority of the source of progestins and estrogens).

What is vaginal cytology?

This is a procedure in which a cotton-tipped swab is used to “swab” or take a cell sample from the surface of

What is the purpose of vaginal cytology?

To determine the stage of the estrous cycle by examining the type of epithelial cells.

What is the significance of the basal cells in vaginal cytology?

They indicate stages of the estrous cycle and are 100% present in anestrus.

What clinical application is associated with an ovariohysterectomy?

Removal of reproductive organs to prevent reproduction.

What is considered normal flora during the estrous cycle?

Bacteria present at any stage that usually have no pathologic significance.

What is the role of estrogen during proestrus?

Gradually increasing estrogen prepares the animal for breeding.

Define 'heat' in terms of female reproductive physiology.

The estrus stage when the female is receptive to mating.

What is the physiological response of female animals during estrus?

Behavioral changes, such as increased vocalization and mating rituals.

When is the hormone LH at its peak?

Alongside ovulation, early in the reproductive cycle.

What is a quit stage in the ovarian or estrous cycle?

An inactive stage, also referred to as anestrus.

What changes occur in the uterus during pregnancy?

Thickening of the endometrium to support the developing fetus.

What is the role of vaginal lubrication?

Facilitate mating process during estrus.

What might happen if the corpus luteum does not receive signals from an embryo?

It degenerates, leading to hormonal changes and the start of a new estrous cycle.

What hormonal changes occur at the end of the cycle and lead to menstruation?

Decline of both estrogen and progestins levels after the corpus luteum degenerates.

What is the relationship between behavior and hormone levels during the estrous cycle?

Hormones directly influence physical and behavioral changes associated with reproduction.

In what way do indoor cats differ in their estrous cycles compared to outdoor cats?

Indoor cats may cycle year-round, while outdoor cats cycle seasonally.

What is the functional unit of the female reproductive system?

Hormones, gonads, and gametes.