Gonads

The reproductive tract includes all of the organs and pathways associated with reproduction. The organ that makes the sex cells, or gametes, is known as a gonad. In males this is the testis, and in females the ovary. Their responsibility is to facilitate the development of viable gametes and their release to the rest of the reproductive tract.

Gender Gonads Gamete

Male Testes Sperm

Female Ovaries Egg

ACCESSORY GLANDS

SEMINAL VESICLES

- absent in cats and dogs

- present in rats, boars, stallions, and bulls

- located behind the bladder, above the prostate and Cowper's gland

- fluid secretion mixes with sperm from vas deferens

PROSTATE GLAND

- present in dogs and humans

- alkaline secretion neutralizes acid of the urethra (male) and vagina (female)

COWPER's GLAND

- also known as bulbourethral gland

- absent in bears and aquatic mammals

- produces fluid known as pre-ejaculate; viscous, clear, salty liquid which neutralizes acid in the urethra

The ovary produces eggs, also known as ovum or oocytes. The ovary will release the egg to the fallopian tubes, which facilitate movement toward the uterus. After ovulation, the ovary will develop a corpus luteum (CL) in the site of the ruptured follicle. The CL is permeated by a dense network of blood vessels that disperse progesterone produced by the CL. Egg development is discussed in more detail in the "gamete development" and "estrous cycle" tabs.

The male produces sperm. Leydig and Sertoli cells in the seminiferous tubules of the testes are very important to proper sperm development. Sperm development is detailed under the "gamete development" tab. Sperm mature in the epididymis and may be stored here until ejaculation through the vas deferens. The sperm will first come into contact with fluid from the seminiferous tubules, then the prostate gland, and finally the Cowper's gland before being ejaculated.

When observing tissues under the telescope, artifacts may appear. These are things that occur during processing but would not be present in the live tissue. For example, air pockets or a grainy appearance of the tissue. In a follicle, the antrum contains follicular fluid. Some follicles may appear to be missing an egg because it is missed by the histological slice. In reality every follicle has an egg.

Antrum

HISTOLOGY

A follicular cyst is when fluid fills the follicle, making it much larger than normal size. The best treatment sequence is as follows:

1) Give GnRH

induces an LH surge
follicular cyst changes into a luteinized cyst.

2) Then give PGF2a

causes luteolysis