Spermatogenesis

Question 1

Which type(s) of sperm cells are undifferentiated and mitotically divide to generate future mature spermatozoa?

Answer 1

Spermatogonia A/B

Question 2

What is the role of FSH in the test diagram?

Answer 2

Supports spermiogenesis, binds to receptors on Sertoli cells

Question 3

What is the role of inhibin and what secretes it?

Answer 3

inhibits FSH production, being secreted by Sertoli cells

Question 4

Describe the pulses in hormonal level

Answer 4

GnRH causes a release of LH/ FSH
episodes occur between 4-8 times in 24 hours
start to see lower FSH levels compared to LH due to inhibin
FSH has a longer half life when compared to LH
-body has a surge of hormones, then negative feedback is initiated

Question 5

describe an overview of compartmentalization of spermatogenesis

Answer 5

Seminiferous tubule: Abluminal compartment—primary/ secondary spermatocyte
—Meosis
T I G H T J U N C T I O N S

                               Basal compartment---primary spermatocyte 
                                                               ----Sertoli cells

Interstitial Tissue: lymphatic channel, blood vessels, Leydig cells

Question 6

What is inside the basal compartment

Answer 6

seminiferous tubule
mitosis, spermatogonia (A,I,B)
most inmature sperm

Question 7

What is in the abluminal compartment

Answer 7

inside the seminiferous tubule
meiosis
primary/ secondary spermatocytes
spermatids

Question 8

How many daughter cells are possible in mitotic divisions

Answer 8

4-g4 daughter cells produced

Question 9

What stage is the earliest you can pull from to use for IVF

Answer 9

Spermatids

Question 10

What are the factors that would cause of apoptosis of germ cells

Answer 10

season, disease, trauma/heat, hormone levels, age, normal part of spermatogenesis

Question 11

Where are the stem cells found and why is the renewal important?

Answer 11

spermatogonia A1: keeps spermatogenesis going: indefinitely
- replenish testis in case of injury, trauma or high heat

Question 12

What is spermiation?

Answer 12

release from the Sertoli cells, where you can find the cytoplasmic droplet

Question 13

what are stages in terms of sperm?

Answer 13

stages are applied to each cross section of a seminiferous tubule
each seminiferous tubule can be at a different stages in any given cross section
- based on the degree of maturation of the cells closest to the lumen
-8 stages
- cells closer to the lumen are more mature, cells closer to the basement membrane are immature

Question 14

what is sperm graduation?

Answer 14

‘gonia-‘ 1 ‘cyte- 2 ‘cyte - ‘tid- spermiation

Question 15

Describe cycles

Answer 15

The TIME it takes the same cross section to complete stages 1-8
- species dependent
-stage 3 returns to stage 3 ( cycles back to the same cycle )

Question 16

Describe waves

Answer 16

spermiation only occurs at certain sites
during a wave, seminiferous epithelium progress through stages
-DISTANCE between the same stage

Question 17

Describe the coordination of stages form waves

Answer 17

some portion of the seminiferous tubule is always releasing sperm

Question 18

Describe the factors of variation in sperm production

Answer 18

testis size, efficiency of spermatogenesis (mitotic division/ degeneration of germ cells), length of spermiogenesis

Question 19

How are Sertoli cells separated from each other?

Answer 19

tight junctions

Question 20

describe the golgi phase in spermiogenesis

Answer 20

development of the acrosome
migration of centrioles

Question 21

Describe what happens in the cap phase

Answer 21

acrosome development cont.
flagellum elongates

Question 22

Describe the acrosomal phase

Answer 22

acrosome developed
manchette: elongation, a series of microtubules, associated with nuclear elongation

Question 23

describe what happens in the maturation phase?

Answer 23

manchette disappears, mitochondria migrates, dense fibers form