Female Reproductive System

Question 1

What are granulosa cells?

Answer 1

Granulosa cells are the cells located between the oocyte and the basal lamina of secondary and Graafian (mature, tertiary) follicles. As granulosa cells develop, they acquire receptors for follicle-stimulating hormone (FSH), which is important in the development of the follicle.

Question 2

What structure originates from the Mullerian ducts?

Answer 2

The oviduct, or uterine tube in primates, is a muscular tube derived from the Mullerian ducts.

Question 3

What is the function of the cervix?

Answer 3

The cervix provides a seal, preventing organisms and substances from entering the cranial vagina and holding the products of conception within the uterus until parturition.

Question 4

What are the different stages of follicular development, or folliculogenesis, within the ovary?

Answer 4

Pre-Ovulatory Follicular Development

1. Primordial follicle
2. Early primary follicle
3. Late primary follicle
4. Secondary follicle
5. Graafian (tertiary) follicle
6. Mature Graafian (tertiary) follicle

Post-Ovulatory Follicular Development

1. Ruptured follicle
2. Corpus hemorrhagicum
3. Corpus luteum
4. Atretic follicle
5. Corpus albicans

Question 5

What cells surround the primary oocyte of secondary follicles?

Answer 5

The primary oocyte of a secondary follicle is enclosed by several layers of follicular cells, called granulosa cells, which proliferate via mitosis.

Question 6

What cells of the mature Graafian (tertiary) follicle, corpus hemorrhagicum, and corpus luteum are targeted by luteinizing hormone (LH)? How do they react in the presence of luteinizing hormone (LH)?

Answer 6

Both granulosa and theca cells of the mature Graafian (tertiary) follicle, corpus hemorrhagicum, and corpus luteum are targeted by luteinizing hormone (LH). During follicular luteinization the granulosa and theca cells undergo hypertrophy and hyperplasia as they transform into luteal cells. The granulosa cells will produce progesterone and estrogens in response to follicle-stimulating hormone (FSH) and luteinizing hormone (LH). In response to luteinizing hormone (LH), theca cells will produce progesterone.

Question 7

What are the zones of the uterine endometrium?

Answer 7

The glandular mucosa of the endometrium is divided into two zones based on their function and structure. The functional zone is the superficial layer that degenerates after pregnancy or estrus. The basal zone is the layer that remains after pregnancy or estrus.

Question 8

What are the major functions of the female reproductive system?

Answer 8

The female reproductive system is responsible for:

• the production of female gametes, or ova (oocytes), via oogenesis (exocrine function)
• the production of sex hormones, mainly estrogens and progesterone (endocrine function)
• the reception of male gametes, or spermatozoa
• providing a suitable environment for fertilization within the ampulla of the oviduct
• providing a sustainable environment for fetal development within the uterus
• providing nutrition for the neonate, or infant (depending on the age)

Question 9

What structures within the oviduct are very active during ovulation?

Answer 9

During ovulation, the cilia of the oviduct are very active and there is an increase in mucous secretions.

Question 10

What are the functions of the oviduct?

Answer 10

The oviduct is responsible for receiving the ovum (oocyte) via the fimbriae of the infundibulum, bi-directional movement of [male and female] gametes, capacitation of sperm, provide a favorable microenvironment for fertilization within the ampulla of the oviduct, and transportation of the fertilized zygote to the uterus for implantation.

Question 11

What hormone is important for estrogen synthesis and ovulation of the ovum?

Answer 11

Luteinizing hormone (LH) is important for estrogen synthesis and ovulation of the ovum from the Graafian follicle. Luteinizing hormone (LH) is produced and secreted by the δ-1 basophilic gonadotropes within the pars distalis of the adenohypophysis (anterior pituitary).

Question 12

What is the corpus albicans?

Answer 12

The corpus albicans is a post-ovulatory follicle composed of fibrous scar tissue resulting from an involution (shrinkage due to inactivity) of the corpus luteum.

Question 13

At what stage of folliculogenesis does the zona pellucida first become apparent?

Answer 13

The zona pellucida can be identified within secondary and Graafian (mature,tertiary) follicles.

Question 14

What are the regions of the ovary? What species is different?

Answer 14

The ovaries in mammals have a similar basic structure: they have an inner region, called the medulla, composed of connective tissue, nerves, blood vessels, and lymphatic vessels and they have an outer region, called the cortex, which is the broad peripheral zone containing follicles at various stages of follicular development. However, in the mature mare the medulla and cortex are reversed and there is an ovulation fossa, which is the only location that cortical tissues remain at the surface.

Question 15

What type(s) of epithilium compose the vagina?

Answer 15

The vaginal epithelium is mostly composed of stratified squamous epithelium with patches of simple columnar epithelium and mucus producing cells.

Question 16

What cells line the primary follicles?

Answer 16

The primary oocyte is enclosed by a layer of simple cuboidal follicular cells within the primary follicle.

Question 17

What structure(s) is/are expelled from the mature Graafian (tertiary) follicle at the time of ovulation?

Answer 17

The oocyte, zona pellucida, and corona radiata are expelled from the mature Graafian (tertiary) follicle at ovulation.

Question 18

What cells line the primordial follicles?

Answer 18

The primary oocyte is enclosed by a layer of flattened simple squamous follicular cells resting on the basal lamina of the primordial follicle.

Question 19

How can you identify a primary follicle from a primordial follicle?

Answer 19

The oocyte within the primary follicle is larger than the oocyte found in a primardial follicle.

Question 20

What are the regions/layers of the uterus?

Answer 20

The uterus is composed of four regions/layers:

1. The endometrium is a very dynamic, glandular tissue lining the lumen of the uterus. The thickness of the endometrium is influenced by hormones.
2. The myometrium is composed of an inner and outer layer of smooth muscle. These muscles aid in the expulsion of the fetus and the placenta.
3. The stratum vasculare houses lymphatic and blood vessels. Hormones can influence the amount of blood flow through these vessels.
4. The perimetrium is the outermost region/layer of the uterus that is lined by a thin layer, about one cell thick, of mesothelium.

Question 21

What are the layers of the oviduct?

Answer 21

The oviduct is composed of two layers:

1. The tunica muscularis of the oviduct composed of a layer of inner circular smooth muscle and a layer of outer longitudinal smooth muscle.
2. The serosa of the oviduct contains blood vessels and nerve fibers.

Question 22

What are the different regions of the oviduct?

Answer 22

The oviduct is divided into four regions:

1. The infundibulum is the dilated, funnel-shaped region of the oviduct. The fimbriae of the infundibulum are finger-like projections surrounding the ovary that “catch” the ovulated oocyte.
2. The ampulla of the region of the oviduct in which fertilization occurs.
3. The fertilized zygote moves from the ampulla to the isthmus.
4. The isthmus then becomes the interstitial part of the oviduct, which opens up to the uterus.

Question 23

What are the two major functions of the ovaries?

Answer 23

The ovaries have an exocrine and endocrine function. The exocrine function of the ovaries involves the production of female gametes, or ova (oocytes). The endocrine function of the ovaries involves the production of sex hormones, mainly estorgens and progesterone.

Question 24

What is the zona pellucida?

Answer 24

The zona pellucida is a glycoprotein layer located at the interphase between the oocyte and the granulosa cells of secondary and Graafian (mature, tertiary) follicles.

Question 25

What are the functions of the uterus?

Answer 25

The uterus provides a sterile (debatable) and inert environment for the development of the conceptus, allows for nutrient exchange and trophic factors via placental attachment sites, and uterine muscles allow for the expulsion of the neonate.

Question 26

What types of cells compose the uterine endometrium?

Answer 26

The endometrial epithelium varies between species. In the mare, bitch, and queen the endometrial epithelium is composed of simple columnar epithelium. In the sow and ruminant species the endometrial epithelium is composed of pseudostratified and/or simple columnar epithelium.

Question 27

What is the purpose of the corpus luteum? What occurs an embryo does not implant within the uterus?

Answer 27

The corpus luteum provides a sustainable environment for pregnancy. If the animal does become pregnant, the corpus luteum will remain for the full-term. If an embryo does not implant within the uterine wall, then the corpus luteum regresses into a corpus albicans.

Question 28

What hormones are involved in uterine contraction?

Answer 28

Uterine contraction is influenced by estrogen, progesterone, oxytocin, and prostaglandin.

Question 29

The corpus luteum has a yellow pigment (lutein) within the luteal cells of some species. What species do not possess this pigment in the corpus luteum?

Answer 29

The yellow pigment (lutein) is not present in the corpus luteum of sows, ewes, and goats.

Question 30

What structures are located in the ovarian cortex?

Answer 30

The cortex of the ovary contains numerous follicles that contain female gametes at various stages of development.

Question 31

What are rugae?

Answer 31

The rugae are the numerous folds within the mucosa layer of the vagina.

Question 32

What is the layer of cells that line the surface of the ovarian cortex? What type of cells are located here?

Answer 32

The germinal, or surface, epithelium lines the surface of the ovarian cortex and is composed of a low cuboidal epithelium.

Question 33

What is the second layer of cells within the ovarian cortex? What type of tissue compose this layer?

Answer 33

The tunica albuginea is the layer of connective tissue beneath the germinal (surface) epithelium within the ovarian cortex.

Question 34

What structure of the oviduct is cut when performing an ovarin historectomy?

Answer 34

The broad ligament of the oviduct is cut when performing an ovarian historectomy.

Question 35

How can you identify a mature Graafian (tertiary) follicle from an early stage Graafian (tertiary) follicle?

Answer 35

The oocyte within a mature Graafian (tertiary) follicle is detached from the cumulus oophorus and floats freely in the liquor folliculi.

Question 36

What hormone is critical to ensure the adequate follicular growth and maturation occurs prior to ovulation?

Answer 36

Proper follicular growth and maturation is dependent on follicle-stimulating hormone (FSH) secreted from the δ-2 basophilic gonadotropes within the pars distalis of the adenohypophysis (anterior pituitary).

Question 37

What cells do you espect to see on a vaginal smear of an animal in estrus?

Answer 37

During estrus, you would expect to find predominantly (>90%) superficial (keratinized) cells, many of which will be anucleated, typically no neutrophils, and variable numbers of erythrocytes.

Question 38

What structure begins to form in an early Graafian (tertiary) follicle?

Answer 38

As the secondary follicle matures into an early Graafian (tertiary) follicle, it increases in size and an antrum begins to form. The antrum is a liquid-filled area between the granulosa cells. The liquid within the antrum is called liquor folliculi.

Question 39

What cells surround the oocyte in a Graafian (tertiary) follicle?

Answer 39

As the antrum enlarges within a Graafian (tertiary) follicle, the oocyte is surrounded by a layer of granulosa cells called the corona radiata, which sits on an aggregate of granulosa cells called the cumulus oophorus.