Nutfah
• Nutfah is a comprehensive term and includes
male and female gametes, zygote, morula,
and blastocyst before implantation and part of
fluid in their natural environments.
• So sperms with seminal fluid, products of
ovulation and the state of insan during first 6
to 7 days or 1st week after fertilization in
intrauterine life are included in the term
Nutfah
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Thus the stages of Nutfah are:
Male and female gametes
Zygote
Morula
Blastocyst
Male Gametes
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1.
2.
3.
4.
5.
6.
Spermatogonia
Primary spermatocytes
Secondary spermatocytes
Spermatids
Spermatozoa
Sperms
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structure of a testis can be described as
Lobules containing interstitial cells of Leydig
Seminiferous tubules embedded in loose CT
Lobules containing 10 to 12 seminiferous
tubules
• Seminiferous tubules lined by stratified
cuboidal epithelium
• Lobules separated by seminiferous tubules
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structure of a testis can be described as
Lobules containing interstitial cells of Leydig
Seminiferous tubules embedded in loose CT C
Lobules containing 10 to 12 seminiferous
tubules
• Seminiferous tubules lined by stratified
cuboidal epithelium
• Lobules separated by seminiferous tubules
Spermatogenesis
• [Gr. Spermato - male seed + Gr. Genesis
production]
• The formation of male gametes is called
spermatogenesis.
• The term spermatogenesis refers to the
sequence of events by which Spermatogonia
are transformed into sperms.
• This is the maturation of male gametes in the
testes, the primary sex organs of male partner.
• The maturation process begins at puberty
(about 14 years) and continues until old age.
• The process of formation of spermatozoa
includes spermatocytogenesis and
spermiogenesis.
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In testis sperms develop from
Spermatogonia cells in ductus deferens
Sertoli cells of seminiferous tubules
Leydig cells of seminiferous tubules
Spermatogenic cells
Spermatozoa in efferent ductules
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In testis sperms develop from
Spermatogonia cells in ductus deferens
Sertoli cells of seminiferous tubules
Leydig cells of seminiferous tubules
Spermatogenic cells C
Spermatozoa in efferent ductules
• Spermatocytogenesis: it includes
1. Mitosis in spermatogonia
2. Differentiation of spermatogonia into
primary spermatocytes.
3. Meiosis in spermatocytes
• Spermiogenesis: It is the transformation of
spermatids into spermatozoa.
• The formation of primary spermatocytes from
spermatogonia is called spermatocytosis.
• The whole process of maturation; starting
from spermatogonia to the formation of
sperms is called spermatogenesis.
• Spermatogenesis begins at puberty. Before
puberty, the seminiferous tubules are in the
form of cords.
• These seminiferous cords have sustentacular
cells of Sertoli surrounded by basement
membrane.
• The spermatogonia cells are sandwiched
between the Sertoli cells and basement
membrane.
• The leftover portion of the process vaginalis
that covers the testes is the
• Gubernaculum testis
• Inguinal canal
• Tunica vaginalis
• Tunica albuginea
• Appendix testis
• The leftover portion of the process vaginalis
that covers the testes is the
• Gubernaculum testis
• Inguinal canal
• Tunica vaginalis C
• Tunica albuginea
• Appendix testis
• Spermatogenesis begins at puberty.
• Before puberty, the seminiferous tubules are
in the form of cords. These seminiferous cords
have sustentacular cells of Sertoli surrounded
by basement membrane.
• The spermatogonia cells are sandwiched
between the Sertoli cells and basement
membrane.
• At puberty, the seminiferous cords acquire
lumen and become seminiferous tubules.
• The spermatogonia start dividing mitotically
and produce Type A spermatogonia.
• These continue to divide by mitosis and
produce more and more Type A
spermatogonia.
• Allah Subhanahu selects some these
Type A spermatogonia cells, and differentiate
them into Type B spermatogonia.
• They continue mitosis and migrate from the
base of Sertoli cells to the lateral walls of
Sertoli cells and further differentiate into
primary spermatocytes.
• Each primary spermatocyte through meiosis-I
forms two secondary spermatocytes.
• Each lobule contains one to three or even
more minute highly convoluted tubules, called
seminiferous tubules, embedded in loose
connective tissue.
Diagram showing microscopic picture of testis.
• This loose connective tissue contains, in
addition to normal constituent cells, groups of
interstitial cells of Leydig, containing yellow
pigment granules.
• These cells are large and polyhedral, with and
eccentric nucleus and poorly staining
cytoplasm. They secrete testosterone.
• There are about 600 seminiferous tubules,
and the length of each is 70 to 80 cm.
• Their diameter varies from 0.12 to 0.3 mm.
• Each tubule is lined by an epithelium called
seminiferous epithelium.
• It is complex stratified epithelium consisting of
two types of cells, sustentacular cells of
Sertolli and spermatogenic cells.
• Sustentacular cells of Sertolli are supportive
cells and spermatogenic cells are germ cells.
• Large cells that nourish developing sperm cells
and form the blood-testes barrier are
• Primary spermatocytes
• Interstitial cells
• Sustentacular cells of Sertoli
• Myoid cells
• Spermatids
• Large cells that nourish developing sperm cells
and form the blood-testes barrier are
• Primary spermatocytes
• Interstitial cells
• Sustentacular cells of Sertoli C
• Myoid cells
• Spermatids
Blood-testis barrier (BTB)
• BTB is a l barrier between the blood vessels
and seminiferous tubules of testis.
Sertoli cell barrier (SCB)
• The name "blood-testis barrier" is misleading
in that it is not a blood-organ barrier in a strict
sense, but is formed between Sertoli cells of
the seminiferous tubule and as such isolates
the further developed stages of germ cells
from the blood.
• A more correct term is the "Sertoli cell
barrier" (SCB).
• The barrier is formed by tight junctions,
adherens junctions, gap junctions and
desmosomes between the Sertoli cells, which are
supporting cells of the seminiferous tubules, and
divides the seminiferous tubule in a basal
compartment (outer side of the tubule, in
contact with blood and lymph) and an adluminal
compartment (inner side of the tubule, isolated
from blood and lymph).
• The presence of the SCB allows Sertoli cells to
control the adluminal environment in which
germ cells (spermatocytes, spermatids and
sperm) develop.
• The barrier also prevents passage of
cytotoxic agents (bodies or substances that
are toxic to cells) into the seminiferous
tubules.
• Each Sertoli cell possesses an ovoid nucleus,
which is often indented;
• Cytoplasm contains numerous organelles,
including mitochondria, rough and smooth
endoplasmic reticulum, ribosomes, Golgi
complex, secretory granules, microfilaments
and microtubules.
• The filaments and tubules probably play a part
in bringing about the changes in the Sertoli
cells that permit the germ cells to ascend the
sides of the cells in their deep recesses, to be
released finally as sperms.
• The functions of the Sertoli cells include:
• 1. The support, protection, and release of the
spermatogenic cells.
• 2. The nourishment of the spermatocytes,
spermatids, and spermatozoa.
• 3. The phagocytosis of the residual bodies derived
from the spermatids.
• 4. The secretion of fluid into the lumen of the
seminiferous tubule for the transport of sperms.
• 5. The formation of small quantities of estrogens.
• From the ejaculatory duct, sperm cells travel
directly into the
• Vas deferens
• Prostatic part of urethra
• Seminal vesicle
• Membranous part of urethra
• Prostate gland
• From the ejaculatory duct, sperm cells travel
directly into the
• Vas deferens
• Prostatic part of urethra C
• Seminal vesicle
• Membranous part of urethra
• Prostate gland