3: Male Histology (Dr. Sun)

- Production of spermatozoa

- Production of hormones (sperm development/maturation, development/maintenance of accessory glands and secondary sex characteristics)

What are the two functions of the testis?

tunica vaginalis

These two layers (visceral and parietal) are parts of which layer?

tunica albuginea

What is 1?

septa (of testis)

What is the arrow pointing to?

septa (of testis)

What is the arrow pointing to?

lobules (of testis)

What area is highlighted in the brackets?

Seminiferous tubules (black arrow)

What has the following characteristics:

- Spermatogenic (aka germinal, seminiferous) epithelium

- - Spermatogenic cells

- - Sertoli (supporting) cells

Interstitial tissue (red arrow)

What has the following characteristics:

- Peritubular (myoid) cells

- Leydig cells: secrete testosterone (major androgenic steroid)

- Macrophages

- CT & Vessels

seminiferous tubules

Which part of the testis contains sertoli cells?

interstitial tissue

Which part of the testis contains Leydig cells?

Leydig cells

What type of cell secretes testosterone?

seminiferous tubules

Which part of the testis produces sperm?

head of epididymis

What is 1?

tunica albuginia

What is 2?

tunica vaginalis

What is 3?

rete testis

What is 4?

body of epididymis

What is 5?

seminiferous tubule

What is 1?

interstitial tissue

What is 2?

1

Does 1 or 2 produce sperm?

2

Does 1 or 2 produce testosterone?

seminiferous tubules (sperm)

Which part of the testis? What is the arrow pointing to?

75 days

How long does development and differentiation of spermatogenic cells take?

200-300 million

How many sperm cells are produced per day?

true

T/F: Sperm production continues throughout life

cooler

Does sperm production favor cooler or warmer body temp?

mitosis

Spermatogenesis undergoes mitosis or meiosis?

Spermatocytogenesis (mitosis)

What has the following characteristics:

- Multiplication & Division of Spermatogonia

- Generation of primary spermatocytes

meiosis

Mitosis or meiosis?

- Reductional & Equational Spermatocyte Divisions Resulting in Haploids Spermatids

spermiogenesis

What has the following characteristics:

- Cytodifferentiation of Round Spermatids to Elongate Forms

- Spermiation

spermiation

Define the following:

Release of Spermatozoa from Sertoli Cells

Oval, round

Cells with __________ (type A) to __________ (type B) shape at the basal lamina (basal compartment)

type A

Which type of spermatogonia remain undifferentiated stem cells and divide by mitosis?

Type B

Which type of spermatogonia divide by mitosis to form primary spermatocytes (spermatocytogenesis)?

false (form during both A and B)

T/F: Cytoplasmic bridges form only during type a divisions

Basement membrane

What is the starred cell representing?

Spermatogonia

What are the arrows pointing to?

diploid

Are primary spermatocytes diploid or haploid?

haploid

Are secondary spermatocytes diploid or haploid?

haploid

Are spermatids diploid or haploid?

secondary spermatocytes

Which stage are spermatocytes rarely observed in?

spermatogonia

What is A?

primary spermatocytes

What is B?

round spermatids

What is C?

elongate spermatids

What is D?

residual bodies

What is E?

cytoplasm bridge

Type A spermatogonia to spermatids have what in common?

heterogeneity

Development of clonal groups yields ______________ within and between seminiferous tubules

crossing over

What generates genetically different sperm compared to somatic cells?

primary spermatocyte

Which stage of sperm development does crossing over happen?

sertoli cells forming blood testis barrier

What protects primary spermatocytes and spermatids from the immune system?

- Adluminal

- Basal (abluminal)

What are the two compartments that make up the blood testis barrier?

sertoli cells

These are functions of what cell?

- Form blood testis barrier

- Produce factors that support germ cells (e.g., ABP/SHBG) in response to FSH

- Produce endothelin

- Phagocytosis of residual bodies & abnormal sperm

sertoli cells

What cells are the arrows pointing to?

spermatids

What is 1?

sertoli cell (nucleus)

What is 2?

tight junction (b/w sertoli cells)

What is the arrow pointing to?

Tight junctions

What type of junctions separate seminiferous tubules into basal & adluminal compartments and protect "genetically different" germ cells?

interstitial tissue, myoid cells

What type of tissue and cell?

myoid cell

What type of cell?

- Myofibroblast-like cells: important for tubular contractility & sperm transport

- Contain androgen receptors, endothelin receptors (endothelin will stimulate contraction)

- Secrete paracrine factors

myoid (IHC for alpha smooth muscle actin)

What type of cells?

arteriole

What is the arrow pointing to?

leydig cell

What cell are the arrows pointing to?

leydig cell

Which cell produces testosterone which is essential for spernatogenesis, accessory gland development & secondary sex characteristics?

leydig cell

ID the cell in blue:

FSH and LH

GnRH stimulates what?

ABP

What does FSH stimulate sertoli cells to release?

Testosterone

What does LH stimulate leydig cells to release?

DHT (dihydrotestosterone)

What is testosterone converted to?

5-a-reductase

How is testosterone converted to DHT?

5-a-reductase

Individuals with___________ deficiency have non-masculinized external genitalia and are usually infertile due to the underdevelopment of reproductive tract glands (prostate, seminal vesicle)

ABP (androgen binding protein)

High levels of testosterone needed for spermatogenesis/ spermiogenesis. 200x plasma levels, achieved by what protein?

cryptorchidism

What condition is the following:

One or both testes fail to descend into scrotum

cryptorchidism

What has the following characteristics:

- Fertility is near zero for the bilateral condition; ~50% for unilateral

- Testicular cancer rates are increased with undescended testes

true

T/F: Leydig and sertoli cells are unaffected by higher temps so crytochid individuals have normal secondary sex characteristics

Prostate

ID #1

Bulbourethral gland

ID #2

Penis

ID #3

Seminal vesicle

ID #4

Ejaculatory duct

ID #5

Ductus (vas) deferens

ID #6

Epididymis

ID #7

Straight tubules (tubuli recti)

ID #1

Rete testis

ID #2

- Seminiferous tubules

- Straight tubules

- Rete testis

What are the three intratesticular structures?

- Duct of epididymus

- Ductus (vas) deferens

- Urethra

What are the three extratesticular structures?

seminiferous tubule terminus

What does the blue dotted arrow show?

sertoli cells only

What type of cells are found in the seminiferous tubule terminus?

Seminiferous tubule terminus

What do these image show?

Efferent ductules

ID the blue box:

rete testis

What do these image show?

rete testis

What has the following characteristics:

- Simple cuboidal epithelium

- Few microvilli

- Collect sperm and propel them downstream via the fibromuscular stroma

efferent ductules

What structure is this?

pseudostratified columnar

What kind of epithelium is found here (and all ducts from here to prostatic urethra are of this type)?

efferent ductules

What has the following characteristics:

- Short cells with microvilli

- Tall cells with cilia (transport non-motile sperm)

- Star-shaped lumen

- Surrounded by smooth muscle

- Resorbs most of fluid from testis

efferent ductules

What ducts are important in reabsorption of testicular fluid?

efferent ductule

What is the only area of ciliated cells in the male reproduction tract?

efferent ductules

What structure?

ciliated cell

What is 1?

Epididymus head

ID #1