Histology - Male Genetalia

Front 1

1.How is the testicular capsule divided?

Back 1

Testicular capsule: Three layers
1.Outer or tunica vaginalis: With parietal and visceral sheets since it is an invagination of the peritoneum. Between both, few liquid exists.
2.Middle or tunica albuginea: Dense connective tissue with smooth muscle.
Inner or tunica vasculosa: Blood vessels and areolar connective tissue.

Front 2

1.What are the seminiferous tubules?

Back 2

Before puberty, just spermatogonia and immature Sertoli cells. It is organized in cords (seminiferous cords) that around the 7th year of life develop a lumen (seminiferous tubules), which are long tubules that start as dead-ends or anastomosing loops. The germinal “epithelium” lines them, and between them we find the interstitium

Front 3

1.What are the Sertoli cells? What are their functions?

Back 3

1.Sertoli cells:
Also known as nurse cells
7% of tubular cells
First cells that appear on the developing gonad
Enable the organization of the spermatic cord
Promotes the differentiation of the Leydig cells
Arrest the development of the spermatogoniae
Average 450 millions (range: 50 to 950 millions)
Regular intervals
Its number determines the amount of spermatogenic cells
Two phenotypes: Immature and mature

Front 4

1.What are the crystalloids of Charcot-Böttcher.

Back 4

Crystaloids of Charcot-Böttcher in the cytoplasm. Unknown function only in mature cells

Front 5

1.Define the blood testis barrier.

Back 5

The blood-testis barrier is created by the tight junctions between Sertoli cells, isolating the adluminal compartment from noxious influences. The structure is created in puberty once the Sertoli cells acquire their mature phenotype.

Front 6

1.Explain the evolution of germinal cells from spermatogonia to spermatozoids.

Back 6

Spermatogenesis starts with the spermatogonia (diploid cell, comes from the yolk sac)
Primary spermatocyte (diploid): large cells
Secondary spermatocyte (diploid, result of first meiotic division, very short life span)
Spermatids (haploid, results of second meiotic division)

Each spermatid becomes a spermatozoid by a process known as spermiogenesis.

Front 7

1.Describe the portions of the mature spermatozoa.

Back 7

Three portions:
1.Head: It has the genetic material and the acrosome, a structure with lysosomal enzymes that allow the cell to penetrate the secondary oocyte.
2.Middle piece: Core of filaments surrounded by mitochondriae.
Tail: 50 micrometres long, provides motion to the spermatozoa.

Front 8

1.What is the spermatogenesis?

Back 8

Creation of sperm

Front 9

1.What is the pampiniform plexus?

Back 9

Blood vessels: Pampiniform plexus maintains the testicle 2ºC below the body temperature.

Front 10

1.What are the tubuli recti?

Back 10

Tubuli recti
At the apex of testicle, they are a short, sharp transitional area between the seminiferous tubules and the rete testis
Only Sertoli’s cells remain, creating a simple columnar epithelium

Front 11

1.What is the rete testis?

Back 11

Network of anastomosing ducts lined by simple cuboidal or squamous epithelium with a single cilium surrounded by coarse connective tissue.

Front 12

1.What are ductuli efferentes?

Back 12

Ductuli efferentes
1.10 to 15 efferent ductules emerging from the rete testis, creating most of the head of the epididymis.
Columnar epithelium with tall ciliated and short non-ciliated cells.

Front 13

1.What is the ductus epididymis?

Back 13

Pseudostratified columnar epithelium with stereocilia.
The tail region of the epididymis is the main site of spermatozoa storage.

Front 14

1.Where do the spermatozoa acquire motility and fertilizability?

Back 14

Ductus epididymidis

Front 15

1.Where are spermatozoa storaged?

Back 15

Ductus epididymidis

Front 16

1.What is the ductus deferens?

Back 16

Ductus deferens
This is the one we cut in vasectomy.
Its muscle experiments powerful contractions during ejaculation.
Prior its end, it dilates into a spindle-shaped structure: the ampulla.
It is surrounded by adventitia.

Front 17

1.What is the ejaculatory duct?

Back 17

Formed by the union of the ampulla of the ductus deferens and the excretory duct of the seminal vesicle.
Mucosa: Outpocketings, pseudostratified or simple columnar epithelium.
Its connective tissue is merged with the one of the prostatic capsule.

Front 18

1.Characterize the gubernaculum.

Back 18

Gubernaculum
Cylindrical gelatinous structure cranially attached to the testis and epididymis in the fetus
Influenced by the Leydig cell
Important in the descent of the testis
Similar to Wharton’s jelly (mesenchyme)

Front 19

1.Define the hydatid of Morgagni (appendix testes).

Back 19

Appendix testes
Found in 90% of males, it is also known as hydatid of Morgagni
Remnant of the cranial portion of the mullerian duct
Attached to tunica vaginalis at the antero-superior portion of the testis

Front 20

1.Describe the seminal vesicles.

Back 20

Seminal vesicles
Diverticulum of the ductus deferens at the end of its ampullary portion.
Primary, secondary and tertiary folds of the mucosa.
Epithelium highly sensitive to hormonal stimuli, age, and other influences.

Front 21

1.What is the function of the seminal vesicles?

Back 21

Secrete a yellowish liquid that nourishes the spermatozoa.
It is not a depot of spermatozoa.
Testosterone-dependent organ.

Front 22

1.In what proportion do the seminal vesicles contribute to the ejaculatory volume?

Back 22

Its secretion makes most of the volume of each ejaculation.

Front 23

1.What are the functions of the prostate?

Back 23

Its milky secretion is important in the liquefaction of the semen

Front 24

1.Describe the topography of the prostate.

Back 24

Epithelia go from cuboidal to columnar depending on the hormonal status.

Front 25

1.What is the difference of the prostatic secretion compared to the secretion of the seminal vesicles?

Back 25

Seminal vesicles: Secrete a yellowish liquid that nourishes the spermatozoa.
Prostate Its milky secretion is important in the liquefaction of the semen

Front 26

1.What are the corpora amilacea?

Back 26

The secretion create concretions known as corpora amilacea [Key feature to identify the structure], jammed in the gland without consequences.

Front 27

1.What are the functions of the bulbourethral glands?

Back 27

Bulbourethral glands

Epithelium goes from cuboidal (low stimuli) to columnar (high stimuli).
Duct that opens at the proximal portion of the penile urethra.
Secretion acts as lubricant, triggered by sexual arousal.

Front 28

1.The penis is made by ________ cylinders of erectile tissue. The two dorsal ones are known as _________________ while the ventral one, that surrounds the penile portion of the urethra, is the ___________________.

Back 28

three, Corpora cavernosa, Corpus spongiosum

Front 29

1.What is the glans?

Back 29

Glans

The skin that covers the distal shaft of the penis has not hair follicles, but small sebaceous and sweat glands
Skin folds distally and creates the prepuce.
The inner face of the prepuce has modified sebaceous glands (glands of Tyson in the coronal sulcus) in some animals. In humans pearly penile papules historically have been mistaken for Tyson glands.

Front 30

1.What is the prepuce?

Back 30

The prepuce has a rich innervation and receptors, all lost in circumcision