Detailed notes on Spermatogenesis It includes Spermatogenesis Spermatocytogenesis Formation of SPERMATIDS Spermiogenesis STRUCTURE of Spermatozoa Diagrams Flowcharts Easy for seminar presentation For MBBS,Dental and Nursing Students Reference from textbook of Clinical Embryology (Vishram Singh)

1. SPERMATOGENESIS
Done by: Abhirami Ajan
1st year BDS
Noorul Islam College of Dental science.

2. SPERMATOGENESIS
• The spermatogenesis is the process of formation of Spermatozoa from
spermatogonia.
• The spermatogonia, which is derived from PGCs(Primordial germ cells) by a
process called Spermatocytogenesis .
• The PGCs are present in the wall of seminiferous tubules of testes till
puberty. At puberty, these cells undergo a series of mitotic division to form
spermatogonia. They start forming gametes, ie, Spermatozoa,and this
countinues throughout the reproductive life of a male, ie, up to old age.

3. The spermatogenesis can be divided into
three phases:
1. Spermatocytogenesis
2. Formation of spermatids
3. Spermiogenesis

4. SPERMATOCYTOGENESIS
• Spermatocytogenesis is a process by which PGCs undergo
repeated mitosis to replace themselves and produce a population
of cells destined to become mature sperms. The PGCs divide by
mitosis to form ainogotamreps A epyt kraD
mets sa tca hcihw ,
hcaE .sllec
muinogotamreps epyt A kraD
ot sisotim seogrednu
mrofone Dark type A and other Light type A spermatogonium.
ehTDark type A spermatogonia are kept in reserve for repetition
of the next cycle. The A epyt thgiL undergoes mitotic division to
form ainogotamreps B epyt kraD owt
.

6. FORMATION OF SPERMATIDS
• The type B spermatogonium undergoes mitotic
division to form two primary spermatocytes.
• The setycotamreps yramirp undergo Frist
meiotic division (reductional division)to form
two secondary spermatocytes. The secondary
spermatocytes thus have haploid number of
chromosomes.
• Each secondary spermatocyte immediately
undergoes citotim.ei( noisivid citoiem dnoces
)AND fo noitacilpud tuohtiw noisividto form two
SPERMATIDS,each with haploid number of
chromosomes.

7. • The SPERMATIDS are small cells of about
half the size of the secondary
spermatocyte and have round and darkly
stained nuclei.
• The SPERMATIDS lies close to the lumen
of seminiferous tubule.

8. SPERMIOGENESIS
• The SPERMATIDS are transformed
into four mature aozotamreps
dellac ssecorp a yb
sisenegoimreps
.

9. STRUCTURE OF SPERMATOZOON
• The SPERMATOZOON(50 microns in
length) consists of head,neck and
tail. The tail is further divided into
three parts: middle piece,
principal piece and end piece.
ruof smrof liaT
-
htgnel eht fo shtfif
.

10. HEAD and NECK
• The head of sperm appears somewhat like a
spearhead in section. It mainly consists of a
nucleus that contain the condensed
chromatin material. Another two-thirds of
the nucleus is covered by an acrosomal cap
that contains various enzymes including
.nisorca dna esadinorulayhThe neck is
narrow. It contains a funnel-shaped basal
plate and a centriole. sevig eloirtnec ehT
tuohguorht sdnetxe taht tnemalif laixa ot esir
liat eht
.

11. TAIL
• Sperm tail has complex anatomy, with surrounding axoneme having 9
+
2
microtubules arrangement along its entire length and peri-axonemal structures
that contribute in sperm motility and fertilization.The tail consists of three
parts:middle principal piece,and end piece.
1. Middle piece: It contains the axial filament in the center, which is surrounded
by spirally arranged mitochondrial sheath. At the distal End of the middle
piece there is a ring-like structure through which axial filament passes. It is
called annulus eloirtnec rehto eht morf devired si dna
.
2. Principal piece: It is made of axial filament covered by seven outer dense
fibers.
3. End piece: tnemalif laixa eht ylno fo edam si tI
.

13. Reference:
Textbook of Clinical Embryology(Vishram Singh)

14. Thankyou