spermatogenesis + semen evaluation

Question 1

three goal of spermatogenesis

Answer 1

produce spermatozoa - cells that are capable of fertilization
replenish supply of primordial stem cells
create genetic diversity

Question 2

3 phases of spermatogenesis

Answer 2

proliferation - mitosis - spermatocytogeneis
- begins with spermatogonia, ends with spermatocytes
meiotic - spermtidogenesis
-begins with primary spermatocytes, ends with haploid spermatids
differentiation - spermiogenesis
- spherical shaped spermatid

Question 3

spermatogenic cell types in order beginning to end

Answer 3

spermatogonia
spermatocytes
spermatids
spermatozoa

Question 4

meiotic divisions

Answer 4

prophase of first meiotic division is long process
lifespan of primary spermatocyte is longer than any other germ cell found in seminiferous epithelium

Question 5

differentiation phase

Answer 5

aim to produce sophisticated self propelled package of enzymes and DNA

Question 5

spermiation

Answer 5

= release into lumen

Question 6

spermatozoa structure

Answer 6

head
- nucleus, acrosome, post nuclear cap
tail
- self powered flagellum
- composed of:
middle piece, principle piece, terminal piece

Question 7

acrosome

Answer 7

contains hydrolytic enzymes required for penetration of zona pellucida

Question 8

cycle of seminiferous epithelium

Answer 8

length cycle varies 4-9wks
spermatogenic wave - differences at any given instant in time along the seminiferous tubule

Question 9

spermatozoa production

Answer 9

1 - produced in testes
2 - mature in head and body of epididymis
3 - stored in the tail of the epididymis until ejaculation

Question 10

the epididymis

Answer 10

transport takes 1-2wks
spermatozoa mature and develop motile capacity
frequent copulation = density in epididymal tail and therefore the ejaculate decreases