The document provides an overview of the male testis, detailing its embryonic development, anatomy, and functions as both an exocrine and endocrine gland. Key components include seminiferous tubules where spermatogenesis occurs, the supportive role of Sertoli and Leydig cells, and the structural layers of the scrotum. It also explains the hormonal influences during development and the descent of the testes into the scrotum.

2. SYNOPSIS
 Introduction to testis
 Embryonic development of testis
 Anatomy
 Scrotum layers
Tunica vaginalis
Tunica albuginea
Tunica vasculosa
 Seminiferous tubules
Spermatogenic cell
Sertoli cell
Leydig cells
 Rete testis
 Efferent ductules
 Testicular arteris
 Summary
 References.

3. TESTIS
 Male gonad.
 Mixed exocrine and
endocrine gland because
they produce sperm and
Secreting male sex
hormones.
 They are contained within
the scrotal sac, which is
located directly behind the
penis and in front of the
anus.

4. EMBRYONIC DEVELOPMENT OF TESTES
 During mammalian development, the gonads are at
first capable of becoming either ovaries or testes.
 week 4, the gonadal rudiments are present within the
intermediate mesoderm adjacent to the developing
kidneys.
 week 6, sex cords develop within the forming testes.

5.  In males, the sex-specific gene SRY that is found on
the Y-chromosome initiates sex determination by
downstream regulation of sex-determining factors,
(such as GATA4, SOX9 and AMH), which leads to
development of the male phenotype.
 first trimester gestation -Testosterone and its potent
derivative, dihydrotestosterone, play key roles in the
formation of male genitalia in the fetus but do not play
a role in the actual formation of the testes.

6.  seventh month of gestation- the testes are formed in
the abdominal cavity and descend into the scrotum, its
stimulated by androgens.
 The production of testosterone by the fetal testes is
stimulated by human chorionic gonadotropin, a
hormone secreted by the placenta.

7. Anatomy:
 Paired, oval gland in the scrotum.
Length = 4-5cm
Diameter = 2.5cm
Mass = 10-15gm(single)
Temperature = 35°c

8. STRUCTURE

9. SCROTUM LAYERS
The scrotum consists of
loose skin and
subcutaneous layers and
supports the testis.
Tunica vaginalis
Tunica albuginea
Tunica vasculosa

10. Tunica vaginalis
 Outer thin ,serous sac .
 Derived from peritoneum.
 Forms during the descent of the testis.
 Partially covers the testes.

11. Tunica albuginea
 Internal to the tunica vaginalis.
 Tough, White fibrous capsule composed of dense irregular
connective tissue called tunica albuginea.
It extents inward
Form septa
Divide testis into serious of internal compartments called
lobules.
Each 200-300 lobules contain 1-3 tightly coiled tubules
called seminiferous tubules(semin-seed,fer-carry).

12. Tunica vasculosa
Testicular artery descends to the inferior pole just deep
to tunica albuginea.

13. Seminiferous tubules
 Each lobules of the testis contain one or
three tightly coiled seminiferous
tubules.
 Uncoiled-70cm in length.
 Functional unit of testis . Because the
spermatogenesis occurs here.
Within the Seminiferous tubules :
Spermatogenic cell:
Here, germ cells develop into
spermatogonia, spermatocytes,
spermatids and spermatozoon through
the process of spermatogenesis.

14. Sertoli cell
 Sertoli cell (a kind of sustentacular cell)
is a 'nurse' cell of the testes that is part of a
seminiferous tubule.
 It is activated by follicle-stimulating
hormone and has FSH-receptor on its
membranes.
 Extend from the basement membrane to
the lumen of the tubule.
 Internal to the basement membrane and
spermatogonia, tight junction joins
neighboring sertoli cells to one another.
 These junction form obstruction known as
blood- testes barrier.

15. EXOCRINE FUNCTIONS:
 Mechanical support.
 Nourishment.
 Phagocytosis of cytoplasmic fragments.
 Release of spermatozoa.
 Blood testis barrier.
ENDOCRINE FUNCTIONS:
 anti-Müllerian hormone (AMH)
inhibin and activin.
androgen binding protein.
Estradiol.
Transferrin.

16. Between tubules (interstitial cells):
Leydig cells :
 cells localized between
seminiferous tubules .
 produce and secrete
testosterone and other
androgens
 sexual development and
puberty,
 secondary sexual
characteristics.
 supporting spermatogenesis.
 Testosterone also controls
testicular volume.

17. Rete testis:
 Once the sperm produced,they move through the
Seminiferous tubules and enter the rete testes for
further maturation.
 Cilia are located on some cells of the rete testis
persumably for moving the sperm.

18. Efferent ductules:
 sperm Transported out of the testis into epididymis
through the series of efferent ductules.
Testicular arteris:
 Arises from the abdominal aorta below the origin of
renal arteris.
 Testis receive blood through the testicular arteris.

19. Summary
It’s a male gonad, paired oval gland in the scrotum.
seventh month of gestation- the testes are formed in
the abdominal cavity and descend into the scrotum, its
stimulated by androgens.
Scrotum layer
Seminiferous tubules.
 Rete testis
 Efferent ductules
 Testicular arteris
Function-spermatogenesis and steroidogenesis.