Difference between revisions of "Rat Reproduction - Anatomy & Physiology"
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== Reproductive tract == | == Reproductive tract == | ||
| − | * | + | * Right ovary is located at the level of L4-5 just caudal to the right kidney. |
| − | ** | + | * Left ovary is located at the level of L5-6 caudal to the left kidney. |
| − | * | + | ** Nearer the midline than the right ovary. |
| + | * Both ovaries are embedded in fat. | ||
| + | |||
| + | * Oviduct is convoluted and winds around the ovary in 10-12 loops. | ||
| + | |||
| + | |||
| + | * [[Female_Reproductive_Tract_-The_Uterus_-_Anatomy_%26_Physiology#Anatomical_Types_of_Uteri|Duplex Uterus]] | ||
| + | ** Two [[Female_Reproductive_Tract_-The_Cervix_-_Anatomy_%26_Physiology|cervices]] | ||
| + | ** Uterine horns remain separate until uniting in a single vagina. | ||
| + | * Vaginal opening lies caudal to clitoral glands and is closed by a membrane until puberty. | ||
| + | * Anastamoses between the ovarian and uterine artery occur in the uterine mesentery. | ||
| + | * Mesovarium and mesometrium contain large volumes of fat, which surround the kidneys, abdominal wall and intestinal loops. | ||
== Oestrous Cyclicity == | == Oestrous Cyclicity == | ||
Revision as of 14:08, 22 July 2008
Male
Penis
- Penis is easily extruded from the prepuce.
- Os penis lies within the tissue of the penis.
Testes
- Two testes in an external scrotum.
- Testes descend between day 30-40.
- Open inguinal canals throughout life.
- Allows the testes to shrink and return to the abdomen during the non-breeding season.
- Head and tail of the epididymis are the sites of extremely large fat pads.
Accessory Sex Glands
Rats have highly developed accessory sex glands. These produce a gelatinous copulatory plug, which is visible in the vagina post-mating and is thought to prevent semen leaking out.
- Seminal Vesicles: Lie dorsolateral to the urinary bladder in contact with the rectum dorsally.
- Large and lobated, opening into the lower end of the ductus deferens.
- Each is enclosed in a capsule together with the coagulating gland.
- Prostate Gland: Bilateral and has three lobes: the dorsal, lateral and ventral.
- Dorsal known is known as the Coagulating Gland.
- Lies close to the seminal vesicle.
- Dorsal known is known as the Coagulating Gland.
- Ampullary Glands: The glands of the ductus deferens.
- Lie near the bladder.
- Bulbourethral Glands: Found near the urethra as it exits the pelvis.
- Preputial Glands: Lie in the subcutaneous fat near the penis and open into the prepuce.
- Sebacious glands that secrete a pheramone used for scent marking.
- Regress with age and fill with stagnant sebum.
Puberty and Sexual Maturity
- Sexually mature at 6-8 weeks
Mammary Gland
- Teats are absent.
Female
Reproductive tract
- Right ovary is located at the level of L4-5 just caudal to the right kidney.
- Left ovary is located at the level of L5-6 caudal to the left kidney.
- Nearer the midline than the right ovary.
- Both ovaries are embedded in fat.
- Oviduct is convoluted and winds around the ovary in 10-12 loops.
- Duplex Uterus
- Two cervices
- Uterine horns remain separate until uniting in a single vagina.
- Vaginal opening lies caudal to clitoral glands and is closed by a membrane until puberty.
- Anastamoses between the ovarian and uterine artery occur in the uterine mesentery.
- Mesovarium and mesometrium contain large volumes of fat, which surround the kidneys, abdominal wall and intestinal loops.
Oestrous Cyclicity
- Non-seasonal polyoestrus
- Oestrus cycle 4-5 days.
- Duration of oestrus is ~14 hours.
Copulation
- Evidence that mating has occured is the 'copulatory plug'
- Forms in the vagina.
Gestation and Offspring
- Gestation length is 20-22 days.
- Litter size 6-16
- Altricial young
- Eyes open at 12-14 days.
- Earliest weaning age 21 days.
- Care not to stress mother or she may cannibalise the young.
Mammary Gland
- 5 pairs of teats.