1. Reproduction
Male

2. Male

3. Role of the male Produce ample amounts of viable sperm
Willing and able to deliver semen (containing sperm)
to female
to AI

4. Anatomy of MALE Paired TESTES Epididimyis Vas deferens Penis Scrotum
Accessory Sex Glands

5. Scrotum Testes descend from near kidney at or near birth
failure: monorchid or chryptorchid
Maintains temp 4-8° cooler than body

6. Temp regulation in testes
External Cremaster muscle
contracts when cold, relaxes when warm
tunica dartos (smooth muscles in skin)
contract when cold
pampiniform plexus
heat exchanger in blood above testicle
esp. stallion & boar

7. The major species differences are related to which accessory sex glands are present and the structure of the penis.

8. Spermatogenesis occurs within the seminiferous tubules of the testes under the metablic and hormonal support of sustentacular and interstitial cells (Sertoli’s cells).
Sperm are stored and mature in the epididymes until resorption or ejaculation.

9. Sperm are produced continually in great numbers
Bull = 5 BILLION sperm per ejaculate
Regulated by FSH
Cells of Leydig secrete testosterone
Regulated by LH

10. Secretions of the accessory glands contribute to the formation of the semen.
The penis contains vascular and connective tissue specializations to produce erection which facilitates intromission.

11. The mammalian male reproductive tract consists of the testes,
a duct system, and related glands.

12. Testes & epididymis
Sperm are produced in the testis and mature in the epididymis.

13. Ductus deferans (vas deferens)
The ductus deferens (vas deferens) propel sperm to the urethra
during ejaculation.

14. Urinary Bladder

15. Ureter

16. Ampulla The ampulla is a glandular region of the terminal portion of
the ductus deferens. It is absent in cats and pigs.

17. Prostrate The prostate gland empties into the urethra.
It provides the bulk of seminal fluid in most species.

18. Vestibular glands (Seminal vessicles)
The vestibular glands vary greatly in size depending on the species.
They are absent in canines and felines.

19. Bulbourethral gland The bulbourethral glands are present in the pig,
equine and bovine, but missing in the canine.

20. Pelvic symphysis

21. Penis Varies by species - Horse: erectile tissue, blood engorgement,
Ram & boar: less erectile tissue. Sigmoid flexure.

22. Dog penis
Os penis
Urethra
Blood sinuses

23. Pig penis

24. Testis
Seminiferous tubules form the mass of the testes and are the sites of
spermatogenesis.

25. Testis
Head of
Epididymis
Tail of
Epididymis

28. Spermatogonia
The spermatogonia are the germ cells of the testis. Unlike
mamallian oogonia, they continue to divide throught life.

29. Primary spermatocytes
The spermatogenic cells--spermatogonia, primary spermatocytes,
secondary spermatocytes, spermatids and spermatozoa--represent
different cell stages in spermatogenesis.

30. Secondary spermatocytes

31. Sustenticular cells
The outlines of sustentacular cells are not distinct. Maturing
spermatozoa are found embedded, head first, in the sustentacular
cells, which provide mechanical support, protection and possibly
nutrition for the developing spermatozoa.

32. Spermatids

33. Basal lamina

34. Factors affecting sperm production
Sexual maturity
Heredity
Underfeeding
Nutrients like Vitamin A, E, protein
Temperature
Testis size
Abnormalities

35. Male Review
Spermatogenesis occurs in the seminiferous tubules of the testes.
Sustentacular and interstitial cells aid the development of spermatogonia into spermatozoa with a nuclear head, mitochondria filled midpiece and a microtubule tail.

36. Sperm are stored and mature as they move through the head, body and tail of the epididymis and into the ductus deferens.
Seminal fluid is formed by the addition of nutrients, buffers and lubricants from the accessory sex glands
(e.g. vesicular, bulbourethral, prostate and ampulla.

37. There is variation among species as to which glands are present.
The penis may contain an os penis in addition to vascular sinuses, (corpus spongiosum and cavernosum) to produce erection.
The urethra is also shared by the urinary tract.