Spermatogenesis

Question 1

spermatogenesis

Answer 1

mitosis (spermatocytogenesis)

meiosis

spermatogenesis

Question 2

role of testes

Answer 2

production of spermatozoa

production of various hormones

Question 3

Spermatogenesis

Answer 3

formation of spermatozoa

from spermatogonia

Question 4

Spermatogenesis definition

Answer 4

spermatocytogenesis + meiosis + spermatogenesis

Question 5

Spermatocytogenesis

Answer 5

proliferation

mitotic divisions involving proliferation and maintenance of spermatogonia

Question 6

meiosis

Answer 6

reduction of genetic material, involves primary and secondary spermatocytes

Question 7

spermatogenesis

Answer 7

differentiation

morphologic transformation of spherical spermatids into spermatozoa

Question 8

Generation of Spermatogonia (basal)

Answer 8

from basement membrane

A1-A2-A3-A4- I (intermediate) - B (proliferation)

number of divisions= species dependent

Question 9

Meiosis phase (Adluminal)

Answer 9

2 phases- first division (primary spermatocyte to secondary spermatocyte)
2nd division= secondary spermatocytes to spermatids

Question 10

Differentiation phase (Adluminal)

Answer 10

spermatids develop and differentiate, travel to lumen

Question 11

Phases of spermiogenesis

Answer 11

Golgi (1-3)= formation of acrostic granule
cap (4-7) = growth of acrostic head cap
Acrosome (8-12) = condensation, elongation and shaping
Maturation (13-14) = final formation of flagellum and neck piece, final condensation and shaping of nucleus

Question 12

Golgi phase

Answer 12

golgi apparatus produces proacrosomic granules and centrioles begin to migrate

acrostic vesicle forms along with granule and centrioles continue moving

Question 13

the cap phase

Answer 13

acrosomic vesicle and granules form and the AX develops further

Question 14

The acrosomal phase

Answer 14

Annulus now present along with Manchete and mitochondria

elongate further

Question 15

the maturation phase

Answer 15

Annulus still present and now have distinct middle, head, neck, and principle piece

Question 16

endocrine regulation of the testis function

Answer 16

secretion of GnRH from the hypothalamus

FSH and LH secretion from the ant. pituitary

testosterone production by Leydig cells

inhibit and active production by sertoli cells

Question 17

Negative feedback

Answer 17

inhibit neg. feedback on Ant. pituitary

testosterone neg. feedback on both hypothalamus and anterior pituitary

Question 18

Ant. Pituitary hormone production

Answer 18

LH- leydig cells- testosterone- spermatogenesis
FSH- sertoli cells- spermatogenesis
FSH-sertoli cells- inhibin- - feedback

Question 19

Stages of the equine seminiferous epithelium and their germ cell types

Answer 19

lots of different types, a spermatogonia may be found in all 8 stages
spermatogonia may be found in stages IV and V

Question 20

Cellular association and animals

Answer 20

more cells associated with smaller animals

Question 21

Spermatogenic cycle

Answer 21

complete series of successive cellular associations (stages) in one seminiferous tubule

Question 22

spermatogenic wave

Answer 22

the distribution of the stages along the length go the tubule in the wave
if the whole length of the seminiferous tubule is viewed at any given time

Question 23

Duration of the cycle of seminiferous epithelium and spermatogenesis

Answer 23

Dog and Bull have longest cycle with the dog reaching 54.4 spermatogenesis and the bull reaching 61

man has the greatest value

boar= shortest cycle

Question 24

epididymis role

Answer 24

low disulfide cross linking (head)

moderate to high degree of disulfide crosslinking (body)

high disulfide cross linking (tail)

***all condensation of chromatin

translocation of cytoplasmic droplet- proximal cytoplasmic droplet (head), distal droplet at tail

Question 25

Sperm chromatin packing in somatic and sperm nucleus

Answer 25

Somatic- DNA wrapped around histone center forming nucleosome which multiple join together forming chromatin fiber (solenoid, supercoiled)

Sperm- minor and major groove intertwine (protamine) via disulfide cross linking which then continue to add up forming chromatin fiber and then a chromatin fiber with a side by side linear array

Question 26

Anisogamy

Answer 26

difference in size of male and female gametes

Question 27

shape of spermatozoa

Answer 27

Bull= longest tail followed by boar, ram and then horse

man is smallest head and tail, rat is hook with extremely long tail and cock is straight and thin which very long postacrosomal region

Question 28

sperm cell head morphology

Answer 28

at tip= apical segment which plasma membrane followed by acrosome contents mostly in principle segment,
surrounded by outer and inner acrosomal membrane with plasma around entire sperm apical, principal and equatorial segments
then in the postacrosomal region there are nucleus and nuclear membrane

Question 29

Sperm tail

Answer 29

mitochondrial helix near posterior head and fibrous helix within inside

Axioneme (9x2) + 2 = outside has 9 groups of 2 subfigure which dynein arm and spokes attached to the central sheath and central droplet

the outer dense fibers are surrounded by fibrous sheath (which is the 9) and then there are longitudinal column of the fibrous sheath on outside (+2)

Question 30

sperm processing

Answer 30

high speed manufacturing - testis

finishing shops- fluid absorption (membrane changes, nuclear and flagellar stabilization, motility and cytoplasmic droplet translocation) - epididymis head and body

warehouse and shipping (storage, spermatozoa for 5-10 ejaculations and smooth muscle contractions upon sexual stimulation) - epididymis tail