Spermatogenesis is the process by which sperm cells are formed in the seminiferous tubules of the testes. It begins with diploid cells near the tubule wall multiplying through mitosis. These cells then undergo meiosis to form haploid secondary spermatocytes and eventually haploid spermatids. Each spermatid then develops into a mature sperm cell which is gradually pushed toward the center of the tubule and stored in the epididymis until ejaculation.

2. SPERMATOGENESIS
Spermatogenes is the formation of
sperm cells. It takes place in the
semniferous tubules.

4.  Diploid cells that begin the process are located near the
outer wall of the tubules.
 These cells multiply constantly by mitosis, and each
day about 3 million of them differentiate into primary
spermatocytes, the cells that will undergo meiosis
 Meiosis I of a primary spermatocyte produces
secondary spermatocytes, each with the haploid
number of chromosomes (n=23).
 Meiosis II then forms four cells, each with the haploid
number of single-chromatid chromosomes (spermatids).

5.  A sperm cell develops by
differentiation of each of
these haploid cells and
gradually pushed toward
the center of the
seminiferous tubule.
 From there, it passes into
the epididymis, where it
matures, becomes motile,
and is stored until
ejaculation

8. SPERM STRUCTURE

9. MALE HORMONES AND THEIR
FUNCTIONS

10. CONT..

11. CONT..

12. CONT..

13. HORMONAL CONTROL OF
SPERMATOGENESIS

14. SEMEN
Semen is grey opalescent fluid , which
consists of suspension of spermatozoa
in seminal plasma.
It is made up of the secretions of all
accessory glands of the male genital
tract.

15. SEMEN

16. SEMEN

17. SPERM COUNT
It is approx. 20 million sperm/ mL (60
million sperms /ejaculation)
Azoospermia: means no spermatocytes
( male sterility)
Oligozoospermia: < 15 million sperms/ mL
Polyzoospermia : >250million sperms /mL

19. EJACULATION
Ejaculation is the discharge of semen
from the penis.
During orgasm, the semen is forcefully
expelled from the body by strong
muscular contractions of sperm ducts.

20. CONT..
During ejaculation, each of the
components that make up semen may be
discharged from the urethra in a
sequence.
The first part is made up of testicular
component of semen followed by
secretion of the prostate , lastly the
secretion of the vesicles are expelled.

21. PATHWAY OF SPERM

22. PROCESS OF EJACULATION
 At the peak of sexual arousal, muscles in the
epididymis, seminal vesicles, prostate gland, and vas
deferens contract.
 At the same time, a sphincter muscle at the base of
the bladder contracts, preventing urine from leaking
into the urethra from the bladder.
 Another sphincter also contracts, closing off the
entrance of the urethra into the penis.

23.  In the second stage of ejaculation, the
expulsion stage, the sphincter at the base of
the penis relaxes, admitting semen into the
penis.
 Simultaneously, a series of strong muscle
contractions around the base of the penis
and along the urethra expels the semen from
the body