Testes
• Embryologically develops in the posterior abdominal wall on the Mesonephros, and
descends through the Inguinal Canal and becomes suspended on the Spermatic Cord.
◦ The descending testis carries with it Tunica Vaginalis derived from Processus
Vaginalis, which invests the testes with Visceral and Parietal Mesothelial
Peritoneal Layers.
• Each Testicle is surrounded by a fibrous capsule called Tunica Albuginea(Collagen,
Fibroblasts), with a fibrous Mediastinal Thickening from which Septa penetrate
dividing the testicle into around 250 Testicular Lobules.
◦ Testicular Lobules contain: Spermatogenesis is a
‣ Interstitial Cells of Leydig which secrete temperature dependent process
Testosterone
• Leydig cells are polygonal cells with central that requires 34°C. The
nuclei and eosinophilic cytoplasm rich in regulation of temperature occurs
Mitochondrial, ER and Lipid droplets which it through various methods:
uses for the Synthesis of Testosterone. 1. Pampiniform Venous Plexus
• The secretion of Testosterone is triggered by contains cooler blood
the Hypothalamus when it secretes
Gonadotropin-Releasing Hormone(GnRH) which 2. Evaporation from the
acts on the Pituitary which secretes a Scrotum
gonadotropin called Luteinizing Hormone 3. Constriction and Relaxation
• However in the Embryo the Gonadotropin from of Cremasteric and Dartos
the Placenta rather than the Gonadotropin Muscles
from Pituitary is responsible for the
stimulation of testosterone synthesis.
‣ 250 to 1000 Convoluted Seminiferous Tubules Hydrocele is the excessive
which produce Sperm accumulation of serous fluid in
• 150 to 250µm in Dimeter and 30 to 70cm in one or both sides of the scrotal
Length sac
• Each Lobule of Convoluted Tubules is
connected via Straight Tubules to the Cryptorchidism is the failure of
Mediastinum which contains Rete Testis from one or both testes to descend
which Efferent Ductules connect to the Head from the abdomen.
of the Epididymis. ◦ Cryptorchidism causes
• Seminiferous Tubules are lined with Germinal the risk of:
or Spermatogenic Epithelium that contains:
◦ Sertoli cells which are sustentacular/ ‣ Infertility
supportive cells and are non-diving that ‣ Testicular Torsion
make up the tubule wall ‣ Testicular Cancer
‣ Columnar/Egg Shaped Testicular Cancer is 95%
‣ Polygonal Spindly Nuclei that is 90° derived from Germ Cells post
to the capsule.
◦ Myoid Cells are flattened peritubular Puberty.
cells that aid in the contraction of
seminiferous tubules.
◦ Spermatogenic Cells which are dividing sperm cells at various stages
of differentiation.
‣ Spermatogenesis is the early differentiation of sperm cells
‣ Spermiogenesis is the final stage of sperm differentiation where
sperm acquires its tail and acrosome
• Different stages of Spermatogenesis can be seen in the
Seminiferous Tubules:
• Type A Spermatogonia which are dark round oval cells
Dividing Sperm Cells all form a attached with tight junctions to the blood-testis
Spermatogenic Syncytium barrier
with intracellular bridges ◦ Undergo Mitosis with 46N Chromosomes
• Type B Spermatogonia are lighter round oval cells that
The reasoning is not clear, but it have committed to Meiosis and have moved to adluminal
space
is thought that free ◦ Undergo Mitosis with 46N Chromosomes
communication can allow the • Primary Spermatocyte which are undergoing Meiosis I
supply of missing component ◦ Undergo Meiosis with 23 Chromosomes
from each spermatogenic cell • Secondary Spermatocyte which are undergoing Meiosis II
and are rarely seen
◦ Undergo Meiosis with 23 Chromosomes
• Spermatids are differentiating sperm cells that are
acquiring morphologic changes or Spermiogenesis
◦ 23 Chromosomes and acquire Acrosome and Tail to
become Spermatozoa
, Tunica Albuginea Seminiferous Tubules Interstitium(septa and fibroblasts)
Tunica Vascularis Blood Vessels Interstitial Cells of Leydig
SPERMIOGENESIS:
• The final stage of Sperm development, which occurs in 4
stages:
◦ Proacrosomal Vesicle develops from the Golgi apparatus
coalesces to form a Acrosomal Cap
◦ Centrioles migrate to the basal aspect and act as
basal Bodies for the developing flagellum
◦ The Acrosomal Cap spread across the apex of the
nucleus
‣ Acrosomal Cap contains Hydrolytic Enzymes such as
Hyaluronidase and Protease Acrosin that dissolve
Zona Pellucida and Corona Radiata of the Oocyte
◦ The Nucleus of the Spermatocyte condenses into tight
histones called Protamines
◦ Flagellum grows a special portion called the Middle
Piece in which ATP required for movement is generated
◦ In the final Steps of Maturation, the excess Cytoplasm
is shed leaving a Residual Body and the Spermatocyte
finally forms into a Spermatozoa or Spermatozoon and
is released into the lumen of the Seminiferous Tubule,
when the tight junction with Basal Sertoli cells is
lost.
Interstitium(Fibroblasts, Septa)Seminiferous Tubule Spermatozoon(acquired morphology)
Primary Spermatocyte Sertoli cells Spermatids(without morphology)
Spermatogonia Interstitial Leydig CellsBlood Vessels
Type A
Type B
• Embryologically develops in the posterior abdominal wall on the Mesonephros, and
descends through the Inguinal Canal and becomes suspended on the Spermatic Cord.
◦ The descending testis carries with it Tunica Vaginalis derived from Processus
Vaginalis, which invests the testes with Visceral and Parietal Mesothelial
Peritoneal Layers.
• Each Testicle is surrounded by a fibrous capsule called Tunica Albuginea(Collagen,
Fibroblasts), with a fibrous Mediastinal Thickening from which Septa penetrate
dividing the testicle into around 250 Testicular Lobules.
◦ Testicular Lobules contain: Spermatogenesis is a
‣ Interstitial Cells of Leydig which secrete temperature dependent process
Testosterone
• Leydig cells are polygonal cells with central that requires 34°C. The
nuclei and eosinophilic cytoplasm rich in regulation of temperature occurs
Mitochondrial, ER and Lipid droplets which it through various methods:
uses for the Synthesis of Testosterone. 1. Pampiniform Venous Plexus
• The secretion of Testosterone is triggered by contains cooler blood
the Hypothalamus when it secretes
Gonadotropin-Releasing Hormone(GnRH) which 2. Evaporation from the
acts on the Pituitary which secretes a Scrotum
gonadotropin called Luteinizing Hormone 3. Constriction and Relaxation
• However in the Embryo the Gonadotropin from of Cremasteric and Dartos
the Placenta rather than the Gonadotropin Muscles
from Pituitary is responsible for the
stimulation of testosterone synthesis.
‣ 250 to 1000 Convoluted Seminiferous Tubules Hydrocele is the excessive
which produce Sperm accumulation of serous fluid in
• 150 to 250µm in Dimeter and 30 to 70cm in one or both sides of the scrotal
Length sac
• Each Lobule of Convoluted Tubules is
connected via Straight Tubules to the Cryptorchidism is the failure of
Mediastinum which contains Rete Testis from one or both testes to descend
which Efferent Ductules connect to the Head from the abdomen.
of the Epididymis. ◦ Cryptorchidism causes
• Seminiferous Tubules are lined with Germinal the risk of:
or Spermatogenic Epithelium that contains:
◦ Sertoli cells which are sustentacular/ ‣ Infertility
supportive cells and are non-diving that ‣ Testicular Torsion
make up the tubule wall ‣ Testicular Cancer
‣ Columnar/Egg Shaped Testicular Cancer is 95%
‣ Polygonal Spindly Nuclei that is 90° derived from Germ Cells post
to the capsule.
◦ Myoid Cells are flattened peritubular Puberty.
cells that aid in the contraction of
seminiferous tubules.
◦ Spermatogenic Cells which are dividing sperm cells at various stages
of differentiation.
‣ Spermatogenesis is the early differentiation of sperm cells
‣ Spermiogenesis is the final stage of sperm differentiation where
sperm acquires its tail and acrosome
• Different stages of Spermatogenesis can be seen in the
Seminiferous Tubules:
• Type A Spermatogonia which are dark round oval cells
Dividing Sperm Cells all form a attached with tight junctions to the blood-testis
Spermatogenic Syncytium barrier
with intracellular bridges ◦ Undergo Mitosis with 46N Chromosomes
• Type B Spermatogonia are lighter round oval cells that
The reasoning is not clear, but it have committed to Meiosis and have moved to adluminal
space
is thought that free ◦ Undergo Mitosis with 46N Chromosomes
communication can allow the • Primary Spermatocyte which are undergoing Meiosis I
supply of missing component ◦ Undergo Meiosis with 23 Chromosomes
from each spermatogenic cell • Secondary Spermatocyte which are undergoing Meiosis II
and are rarely seen
◦ Undergo Meiosis with 23 Chromosomes
• Spermatids are differentiating sperm cells that are
acquiring morphologic changes or Spermiogenesis
◦ 23 Chromosomes and acquire Acrosome and Tail to
become Spermatozoa
, Tunica Albuginea Seminiferous Tubules Interstitium(septa and fibroblasts)
Tunica Vascularis Blood Vessels Interstitial Cells of Leydig
SPERMIOGENESIS:
• The final stage of Sperm development, which occurs in 4
stages:
◦ Proacrosomal Vesicle develops from the Golgi apparatus
coalesces to form a Acrosomal Cap
◦ Centrioles migrate to the basal aspect and act as
basal Bodies for the developing flagellum
◦ The Acrosomal Cap spread across the apex of the
nucleus
‣ Acrosomal Cap contains Hydrolytic Enzymes such as
Hyaluronidase and Protease Acrosin that dissolve
Zona Pellucida and Corona Radiata of the Oocyte
◦ The Nucleus of the Spermatocyte condenses into tight
histones called Protamines
◦ Flagellum grows a special portion called the Middle
Piece in which ATP required for movement is generated
◦ In the final Steps of Maturation, the excess Cytoplasm
is shed leaving a Residual Body and the Spermatocyte
finally forms into a Spermatozoa or Spermatozoon and
is released into the lumen of the Seminiferous Tubule,
when the tight junction with Basal Sertoli cells is
lost.
Interstitium(Fibroblasts, Septa)Seminiferous Tubule Spermatozoon(acquired morphology)
Primary Spermatocyte Sertoli cells Spermatids(without morphology)
Spermatogonia Interstitial Leydig CellsBlood Vessels
Type A
Type B
