Anatomy and Physiology:Reproductive Systems (3025B)

By

Jessi Spry and Kathryn Shaull

General Information 1

• Reproduction is a complicated process in all species of animals

http://piximg.corbis.com/cpe/256wm/101http://asnet.tamu.edu/www/ansc108/PICS/Boar.jpg53713.jpg

General Information 2

• The anatomy of both the male and female must be compatible.

General Information 3

• Physiological compatibility and timing is also required– Must have similar genetic makeup– The female must be willing in heat to accept the

male– Ovum must be mature and ready to be fertilized– Dependent on the proper function of many

organs

General Information 4

• Any abnormality in the anatomy or physiology of the reproductive tract result in lower fertility or complete sterility of the animal

Anatomy of the Male Reproductive Tracts

• Less complex than the females.

• Goal is to produce large numbers of viable male sex cells called spermatozoa.

• Contributes ½ of the chromosomes to each of his offspring

Male Reproductive Tracts

• After mating the role of the male is over

• Reproductive organs in the various mammalian species are similar in form and function

Male Reproductive Tract-Picture

http://frost.ca.uky.edu/agripedia/asc106/reprmale.htm

Scrotum

• Testes or testicles in the male are the primary sex organs and are held in a sac called the scrotum– Produce spermatozoa

and testosterone

– Normally two testicles in a scrotum

Scrotum

– Functions as a heat regulating mechanism.

• 4 or 5 degrees below body temp. is essential for spermatogenesis – growth and maturation of the sperm

Testicles

• Some animals only have one or neither testicle drop out of the body cavity into the scrotum– A monorchid as one fertile testicle– Although the testicle in the body does not

produce viable spermatozoa, it does produce testosterone

– Cryptorchid is sterile and means neither dropped.

Urethra

• Begins at the opening of the bladder and is continuous with the penis.– In mature bulls, the

posterior portion of the urethra is S-shaped – known as the sigmoid flexure

Urethra

• Extends the penis outside of the body and into the vaginal cavity of the female so that the semen can be deposited.

Urethra

– If the Sigmoid flexure does not work you have the equivalent of the sterile male

– The retractor muscle retracts the penis into the protective sheath

Urethra

• “Accessory Sex Glands” along the urethra include the:– Prostate Gland– Two seminal vesicles– Two Cowper’s

Urethra

• The accessory Sex Glands provide a medium for the transport of the sperm from the testes to the vagina.

• The Medium includes:– Adds Volume

– Provides Nutrients for the sperm

– Cleans and flushes out the urinary tract.

– Makes a plug to hold the semen in the vagina (in some species)

Any Questions?

Important Roles of Females

• Provides 1/2 of the chromosomes of the young

• Nourishes young in her uterus and after birth until weaning

Female Reproductive Tract

• Female Tract consists of:– Vulva– Vagina– Cervix– Uterus– Uterine horn– Fallopian tubes– Ovarieshttp://frost.ca.uky.edu/agripedia/asc106/reprfema.htm

Vulva

• Exterior portion of the reproductive tract

Vagina

• Region between the vulva and the cervix

• Semen is deposited in this region in cows and ewes

Vagina Compared

• Length (Vagina + Vestibule)– Cow 35-42 cm

– Ewe 12-17 cm

– Sow 16-23 cm

– Mare 30-47 cm

• Semen deposit– Cows and ewes have semen deposited here, mares and

sows have semen deposited in cervix.

Cervix

• “Mouth of womb”– The opening into the uterus through which

sperm must pass to fertilize the egg.

• Semen deposited here in mares and sows

• Area stretches during birth to allow passage of newborn

• Becomes blocked by mucus plug to protect it from harmful infections

Cervix

Uterine Horns

• The two branches of the uterus

• Fallopian tubes or ovuducts are located at the end of each horn

• lined with microscopic cilia– help guide egg (ovum) to the horn

• Usually the site of sperm and ovum uniting

Uterine Horns

http://frost.ca.uky.edu/agripedia/asc106/uteruses.gif

Any Questions?

Value of Castration

• Definition: removal of the testicles by either surgical or non-surgical methods

Ages for Castration

• Recommended– Calves: 1-3 months– Lambs: 7-14 days– Pigs: 1-3 weeks

http://asnet.tamu.edu/www/ansc108/PICS/Boar.jpg

Why Castrate

• Makes male animals less aggressive and easier to handle

•http://www.viewimages.com/viewimage/?imageid=102497&promotionid=1&partnerid=2&type=results

Aggression

• Due to the effects of “androgens”– androgens: hormones that control the

appearance and development of masculine sex characteristics

• Removal of testes stops production

• Primary androgen is “testosterone”

Selected Resources

• http://piximg.corbis.com/cpe/256wm/101http://asnet.tamu.edu/www/ansc108/PICS/Boar.jpg53713.jpg

• http://frost.ca.uky.edu/agripedia/asc106/reprmale.htm

• http://frost.ca.uky.edu/agripedia/asc106/reprfema.htm

• http://frost.ca.uky.edu/agripedia/asc106/uteruses.gif

• http://asnet.tamu.edu/www/ansc108/PICS/Boar.jpg

• http://www.viewimages.com/viewimage/?imageid=102497&promotionid=1&partnerid=2&type=results