Animal Reproduction/Theriogenology https://www.youtube.com/channel/UCHzZhYqMy10vsVRZdddEkUg

1. 1
Male
Reproductive
System as a
manufacturing
complex
Lecture # 3 (THER 806)

2. 7
Segments in Male Reproductive
Tract
• Spermatic Cord
• Scrotum
• Testis
• Excurrent duct system
• Accessory sex glands
• Penis and muscles for protrusion, erection and
ejaculation

3. Extirpated
Bull
Reproductive
Tract
3

4. Functions of the Spermatic Cord
• Provide Vasculature, lymphatic and
neural connection to the body
• Provide a heat exchanger
• House the cremaster muscle
4

5. 5
Anatomy of Male Reproduction
• Male Gonads, the testis, lie outside abdomen
within scrotum derived from skin & fascia
• Each testis further lies within a vaginal process a
separate extension of peritoneum. They pass
through “inguinal canal|” with ‘deep’ and
‘superficial’ rings
• Blood vessels and nerves reach the testis in
spermatic cord which also lies within the vaginal
process.

6. Functions of the testes
• To produce spermatozoa
• To produce hormones and proteins
• To produce fluids
6
• Testicular capsule
• Parenchyma
• Mediastinum
• Rete tubules
The testis consists of

7. Testicular parenchyma consists of
• Seminiferous tubules
• Interstitial cells of Leydig
• Capillaries
• Lymphatics
• Connective tissue
7
• Seminiferous epithelium
• Sertoli cells
• Developing germ cells
• Peritubular cells
The tubular compartments consists of

8. 8
Thermoregulation of Testis
• Testis for effective functioning must be maintained at the
temperature lower than that of body.
• Temperature receptors are present in the scrotal skin
• In cold conditions contraction of the smooth muscles, and
elevation of the testis and wrinkling of the skin occur.
• In hot conditions muscles relaxes and lowering testis in
pendulous scrotum
• Testicular artery is a convoluted structure & arterial coils
are enmeshed by ‘pampiniform plexus’ of testicular vein
• By virtue of countercurrent mechanism arterial blood is
cooled by venous blood leaving the testis

9. Vascular
Heat
Exchanger
9

10. 10
Development
Descent of the testis.
• Inguinal ligament of the gonad is called the gubernaculum
testis
• Failure of testis to enter scrotum cryptorchidism
(unilateral or bilateral)
Postnatal development
• Capacity for erection of the penis precedes the appearance
of sperm in ejaculate by several months
• The period of rapid development that precedes puberty is
known as pre pubertal period
• The period after puberty is called as post pubertal
• During the post pubertal period development continues and
the reproductive tract reaches full sexual maturity months
or several years later

11. Longitudinally
incised testes
11

12. 12
Basal Compartment
Adluminal
Compartment
Sertoli cells (FSH)
Large, diffused cytoplasm of
tubule forms a barrier which
isolate the difference ting
germ cells from general
circulation.
Spermatogonium
Lies in the outermost
Spermatocyte
Located inside the
layer of Sg and Sc
Spermatids, round
Located internally to
spermatocyte
Spermatozoa production: main
function
Germinal Cells & Sertoli Cells
Arrangments in Seminiferous Tubule
BLOOD TESTIS
BARRIER

13. Blood-testis barrier
• Prevents immunologic destruction
of the developing germ cells
13

14. 14
Interstitial Tissue of Testis
Steroid (T)
production is
the main
function

15. 15
Development of Male Reproductive
Tract in Farm Animals
Bull
(Holstein)
(weeks)
Buffalo Bull
Weeks (months)
(Ahmad et al., 1987)
Ram
(weeks)
P. Spermatocyte in SNT 24 48 (12) 12
Sperm in SNT 32 72 (18) 16
Sperm in cauda epididymis 40 72 (18) 16
Sperm in ejaculate 42 96 (24) 18
Separation between penis
and penile part of prepuce
32 60 (15) >10
Age of sexual maturity 150 192 (36) >24

16. Epididymis
of a typical
mammal
16

17. 17
Epididymis
• Caput, (head) corpus (body) and cauda (tail)
• Progressive decrease in height of the epithelium
and stereocilia and widening of lumen
• Maturation of sperms occur during transmit
through epididymis
• Sperm stored in epididymis retain fertilizing
capacity for several weeks, cauda stores ~75% of
the total epididymal sperm
• Do the sperm in the testis have the ability to
fertilize?
• What is the fate of unejaculated Spermatozoa?

18. 18
Histological Cross Section of Epididymis
Sperm stored
Cilia
Tall columnar
epith cells

19. Seminal Plasma is produced by the
• Epididymis
• Ampulla
• Vesicular gland
• Prostate gland
• Bulbouretheral glands (Cowper’s
gland)
19

20. 20
Accessory Glands
• Seminal vesicles, in ruminants are compact
lobulated glands, lies laterally to the terminal part
of ductus deferens. They provide liquid vehicle for
the transport sperm, Contribution in the addition
of specific chemical agents to the ejaculate eg.,
fructose and citric acid.
• Prostrate glands are lobulated, external part of
the body lies out side the thick uretheral muscle.
• Bulbouretheral gland is dorsal to the urethera in
bull hidden by bulbo spongiosus muscle.

21. 21
Erection and Protrusion
• Sexual stimulation, produces dilatation of arteries,
supplying cavernous bodies of penis.
• Stiffening and straightening of the penis is caused
by ischiocavernosus muscle.
• Intromission in the bull lasts for about few
seconds.
• Straightening of the penis after withdrawal occurs
abruptly.
• Erectile dysfunction (ED) = impotence, whereas
male infertility = temporary impairment of the
semen picture

22. 22
Structure of Penis
paired
It consists of
• A base
• A shaft
• The glans penis