Male Reproductive System I

Question 1

What is testicular determining factor (TDF)?

Answer 1

A transcription factor from the Y chromosome that causes fetal gonad differentiation.

Question 2

How are the primitive sex cords formed? What do these eventually become?

Answer 2

When primordial germ cells from the yolk sac endoderm migrate into the genital ridge. Eventually becomes the serminiferous tubules.

Question 3

What do Sertoli cells, intersitial cells, and CT derive from?

Answer 3

Mesoderm.

Question 4

What is the tunica vaginalis?

Answer 4

The double-layered covering of the anterior testis.

Question 5

What is the testicular capsule made of? What is a fancy word for it?

Answer 5

AKA tunica albuginea. Made of dense fibrous CT.

Question 6

What is the mediastium testis? What other important structure is found here?

Answer 6

An area of the posterior testis where the CT of the tunica albuginea gets thick. The rete testis is found here.

Question 7

Where is the tunica vasculosa found and what does it contain?

Answer 7

Found deep to the albuginea in the testis, contains lymphatics and blood vessels.

Question 8

What separates testicular lobules? How many seminiferous tubules are found in each lobule?

Answer 8

CT septa separates. 1-4 tubules per lobule.

Question 9

What type of epithelium is found in the seminiferous tubule wall?

Answer 9

Stratified seminiferous epithelium.

Question 10

What cells are found deep to the basal lamina in the seminiferous tubules?

Answer 10

Contractile peritubular myoid cells, fibroblasts, CT.

Question 11

What two cell types are found in the seminiferous tubules?

Answer 11

1. Spermatogenic cells

2. Sertoli cells (supporting cells)

Question 12

What are the four phases of spermatogenesis?

Answer 12

1. Spermatocytogenesis
2. Meiosis
3. Spermiogenesis
4. Spermiation

Question 13

What happens during spermatocytogenesis?

Answer 13

Generation of primary spermatocytes.

Question 14

What is spermiogenesis?

Answer 14

Cytodifferentiation

Question 15

What is spermiation?

Answer 15

Release of spermatozoa (sperm) from the sertoli cells.

Question 16

In which spermatogenic cells does crossing over take place?

Answer 16

Primary spermatocytes.

Question 17

What do Type A and B spermatogonia do?

Answer 17

Type A remain stem cells. Type B differentiate.

Question 18

Which spermatogenic cell moves up from the basal lamina in seminiferous tubules?

Answer 18

Primary spermatocytes.

Question 19

Which spermatogenic cell is the largest and most prominent in histologic sections?

Answer 19

Primary spermatocytes.

Question 20

What do secondary spermatocytes look like in histologic sections?

Answer 20

Trick question! They have a short half life and are rarely seen!

Question 21

What do early spermatids look like?

Answer 21

Small round cells with a heterochromatic nuclei.

Question 22

What do late spermatids look like?

Answer 22

Condensed nuclei and tapered cell body with a tail.

Question 23

When are the cytoplasmic bridges between spermatogenic cells broken?

Answer 23

When they are released into the lumen of the seminiferous tubule. This is called the “clonal nature of sperm development.” -sounds like something Dr. G would be stoked on.

Question 24

What are the five steps of spermiogenesis?

Answer 24

1. Acrosome formation.
2. Centriole migration and flagellum formation.
3. Mitochondria migration.
4. Condensation of the nuclear chromatin.
5. Sloughing of residual bodies.

Question 25

What does the acrosome arise from?

Answer 25

The Golgi.

Question 26

What is found in the acrosome?

Answer 26

Enzymes! Hyaluronidase, neuraminidase, acid phosphatase, trypsin-like protease, and other PAS-positive carbohydrate rich components!

Question 27

What is a residual body?

Answer 27

"Extra" cytoplasm of spermatozoa that glob off before they are released into the lumen.

Question 28

What do Sertoli cells look like? What are they under the influence of?

Answer 28

Long cells that sit on the basal lamina and extend towards the lumen of the seminiferous tubule. Under influence of FSH.

Question 29

Name five things that Sertoli cells do.

Answer 29

1. Form gap junctions with neighboring cells. 2. Form the blood-testis barrier. 3. Phagocytose residual bodies. 4. Secrete fluid, androgen binding protein (ABP), activin, and inhibin. 5. Physical support.

Question 30

What do activin and inhibin do?

Answer 30

Activin stimulates FSH from pituitary. Inhibin inhibits.

Question 31

What is found in the spaces between seminiferous tubules?

Answer 31

Interstitial containing CT, nerves, blood, lymphatic vessels, and Leydig cells.

Question 32

What are Leydig cells derived from?

Answer 32

Embryonic genital ridge mesoderm.

Question 33

What do Leydig cells do? What are they inder the influence of?

Answer 33

Secrete testosterone, DHEA, and 5-alpha-androsteindione. Under influence of LH

Question 34

Why is the blood-testis barrier important?

Answer 34

Spermatogenesis does not occur until after puberty, so the proteins created during the process may be considered "foreign" by the immune system. The barrier blocks immune attack.

Question 35

Junctional complexes on the _________ aspect of Sertoli cells make up the blood-testis barrier.

Answer 35

Lateral

Question 36

What are the two compartments of the seminiferous tubule with regard to the blood-testis barrier?

Answer 36

1. Basal compartment | 2. Adluminal compartment.

Question 37

Are spermatogonia and spermatocytes that are touching the basal lamina accessible by things that cross the basal lamina?

Answer 37

Yup

Question 38

Define the adluminal compartment of the seminiferous tubule.

Answer 38

The area between the Sertoli cell lateral junctional complexes and the lumen.

Question 39

Which spermatogenic cells can one find in the albuminal compartment of the seminiferous tubule?

Answer 39

Primary, secondary spermatocytes, and spermatids.

Question 40

What happens to testosterone in the seminal vesicles, bulburorethral glands, and external genetalia?

Answer 40

Converted to DHT by 5-alpha-reductase.

Question 41

What happens to testosterone in the peripheral tissues?

Answer 41

Converted to estradiol by aromatase.

Question 42

What is prolactin's role in the male reproductive system?

Answer 42

Increases the effect of LH on Leydig cells.

Question 43

What effect does FSH/LH have on Leydig cells?

Answer 43

Stimulates them to make testosterone.

Question 44

What is cryptorchism?

Answer 44

Failure to descend.

Question 45

What is the order of ducts that a sperm will encounter, beginning at the seminiferous tubule?

Answer 45

Seminiferous tubule --> rete testis --> duculi efferentes --> epididymis --> ductus deferens

Question 46

Spermatogonia have __N DNA.

Answer 46

2N DNA. These are the precursor cells for meiosis.

Question 47

Primary spermatocytes have __N DNA.

Answer 47

4N. These have copied their DNA prior to any meiotic division.

Question 48

Secondary spermatocytes have __N DNA.

Answer 48

2N DNA. They have done the first meiotic division.

Question 49

Spermatids have __N DNA.

Answer 49

1N DNA. They have completed meiotic divisions.