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The Female Reproductive
System
The ovaries are the female
gonads. They are located in the dorsal part of the abdominal
cavity. Ova develop in follicles in the ovary. The
follicles also produce the hormone estrogen which causes the signs of
"heat." When the ovum is released at ovulation the empty
follicle is converted into a solid corpus luteum which
produces the hormone progesterone necessary for the
maintenance of pregnancy.
Follicle development
 |
Feline ovary
with follicles |
(400X) |
Primordial follicles
Dormant oocytes surrounded by flattened follicular cells
. |
(400X) |
Early developing follicle
the follicular cells on the right have become more cuboidal. |
(100X) |
Early developing follicle
the follicular cells have begun to multiply. |
(100X) |
Developing follicle
the follicular cells are continuing to multiply. |
(100X) |
Early mature follicle
the antrum is beginning to form. |
(100X) |
Developing mature follicle
with enlarging antrum. |
 |
Feline ovary with corpora lutea |
The oviduct is a tubular extension of the
uterine horns which has no direct connection to the ovaries. Its
enlarged, funnel-like end, the infundibulum, partially
surrounds developing follicles and catches ova at ovulation.
Fertilization of ova usually occurs in the oviduct.
The uterus is a hollow, muscular organ
where the offspring develops. In most domestic animals it is Y-shaped
with a body and two horns.
|
Cat ovary, oviduct, and uterus |
The cervix is a powerful smooth muscle
sphincter between the uterus and vagina.
The vagina receives the erect penis during
breeding and is the birth canal.
The vulva is the external portion of the
female reproductive tract. The urethra opens on the floor of
the vestibule, the short space between the vagina and the
labia, the external boundary of the vulva. The clitoris
is homologous to the penis of the male.
Canine vulva
The estrous cycle is the period from the
beginning of one heat period to the beginning of the next. It can be
divided up into 4 stages:
 | Proestrus:
follicle develops in ovary |
| Estrus:
follicle is mature - heat period |
| Metestrus:
corpus luteum develops |
| Diestrus:
corpus luteum is mature |
| (Anestrus):
period of ovarian "shut-down" in some species |
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