General idea about the histology of the Testes. the gross anatomy and the major structures important for the understanding of the microscopic structures of testes including spermatogenesis and spermiogenesis can be found. Also the practical identification of a testes can also be found in this presentation. the Staining used for each and every slide shown in the presentation are the H&E staining that gives the pink and purple coloured slides.

1. TESTES..
Shlok Mathur...

2. • The adult testes are paired ovoid organs placed
outside the body in scrotum.
• The right and left testes produce the male
gametes or spermatozoa.
• The testis lies within a double layered serous sac
called the tunica vaginalis.
• The testes develop retroperitoneally in the
dorsal wall of the embryonic abdominal cavity
and are moved during fetal development to
become suspended in the two halves of the
scrotal sac, or scrotum, at the ends of the
spermatic cords
• Arterial Supply : Testicular artery
• Venous Drainage : Pampiniform venous plexus
Introduction..

3. Low Magnification :
• Seminiferous Tubules
• Interstitial cells
• Tunica Albuginea
• Blood vessels
High Magnification :
• Sustentacular cells (Sertoli)
• Spermatogonia
• Spermatocytes
• Spermatids
• Spermatozoa
• Interstitial cells of Leydig
Identification..

4. • The bulk of each testis consists of seminiferous
tubules embedded in relatively sparse interstitial
tissue.
• Sperm cells are produced by the tubules, while
hormones are produced by endocrine cells
(Leydig cells) within the interstitium.
• The Interstitial cells produce the steroid hormone
testosterone, which promotes development of
the secondary male sex characteristics.
• Apart from interstitial cells, the interstitial tissue
contains collagen fibres, fibroblasts,
macrophages, mast cells, blood vessels and
lymphatics.
Interstitial Tissue..

5. • Leydig cells, also known as
interstitial cells of Leydig, are found
adjacent to the seminiferous tubules in
the testicle.
• Leydig cells, develop as large round or
polygonal cells with central nuclei and
eosinophilic cytoplasm rich in small
lipid droplets.
• Some interstitial cells may be present in
the mediastinum testis, in the
epididymis, or even in the spermatic
cord.
• Testosterone secretion by interstitial
cells is triggered by the pituitary
gonadotropin, luteinizing hormone
(LH), which is also called interstitial cell
stimulating hormone (ICSH).
Leydig cells..

6. • These are tall, slender cells having an irregularly
pyramidal or columnar shape. The nucleus lies
near the base of the cell. It is light staining and is
of irregular shape. There is a prominent nucleolus.
• Sertoli cells are the somatic cells of the testis that
are essential for testis formation and
spermatogenesis.
• Sertoli cell functions as elaborate tight occluding
junctions between their basolateral membranes
that form a blood-testis barrier within the
seminiferous epithelium.
• Other functions are :
Support, protection, and nutrition of the developing
spermatogenic cells
Exocrine and endocrine secretion
Phagocytosis
Sertoli Cells..

7. • Seminiferous tubules are highly convoluted structures
present in each lobule of the testes.
• Within a lobule, the spaces between seminiferous
tubules are filled by very loose connective tissue,
containing blood vessels and lymphatics.
• The wall of each tubule is made up of an outer layer of
fibrous tissue that also contains muscle-like (myoid)
cells. Contractions of these cells probably help to
move spermatozoa along the tubule.
• There are various layers of cells present in the tubules,
most of the cells represent stages in the formation of
spermatozoa, they are referred to as germ cells.
• Other cells that have a supporting function are called
sustentacular cells or the cells of Sertoli.
Seminiferous Tubules..

8. • Spermatogenesis is the process by which haploid
spermatozoa develop from germ cells in the
seminiferous tubules of the testis.
• This process occurs in waves along the length of
seminiferous tubules taking about 64 days to
complete.
• Spermatogonia with dark, ovoid nuclei act as stem
cells, dividing infrequently and giving rise both to
new stem cells and to cells with more pale-staining,
ovoid nuclei that divide more rapidly as transit
amplifying (progenitor) cells.
• Spermatogenesis can be divided into three phases:
(1) proliferation and differentiation of
spermatogonia, (2) meiosis and (3) spermiogenesis.
Spermatogenesis..

9. • Spermiogenesis is the final stage of
spermatogenesis, which sees the
maturation of spermatids into mature
spermatozoa.
• Spermiogenesis includes formation of
the acrosome condensation and
elongation of the nucleus, development
of the flagellum, and the loss of much
of the cytoplasm.
• Spermiogenesis is commonly divided
into four phases:
Golgi Phase
Cap phase
Acrosome Phase
Maturation Phase
Spermiogenesis..

10. Thank you..
Doubt?..