Spermatogenesis and Semen Evaluation

Question 1

3 goals of spermatogenesis

Answer 1

Produce spermatozoa
Replenish supply of primordial stem cells
Create genetic diversity

Question 2

Spermatozoa

Answer 2

Cells that are capable of fertilisation

Question 3

3 phases of spermatogenesis

Answer 3

Proliferation phase (mitosis) (spermatocytogenesis)
Meiotic Phase (spermatidogenesis)
Differentiation phase (spermiogenesis)

Question 4

Key parts of gross anatomy of testis

Answer 4

Head of epididymis
Testis
Tail of epididymis
Vas deferens

Question 5

Sertoli cells

Answer 5

Support the process of spermatogenesis (structurally, provides nutrients and fluids, clears waste)
Tall cells from basement membrane to the lumen
Forms tight junctions (creates physical barrier)

Question 6

Name of the barrier that divides the seminiferous tubule

Answer 6

Sertoli cell barrier
Sperm-testis barrier
Blood testis barrier

Question 7

2 compartments that the seminiferous tubule is divided into

Answer 7

Basal compartment

Adlumenal compartment

Question 8

Spermatogenic cell types (and what compartment)

Answer 8

Spermatogonia (basal)
Spermatocytes (adlumenal)
Spermatids (adlumenal)
Spermatozoa (adlumenal)

Question 9

Proliferation phase

Answer 9

Spermatogonia (spermatogonial stem cells)
Cells divide and replicate by mitosis
Parent cell to 2 daughter cells diploid and genetically identical
Number of divisions depends on species
Some spermatogonia B cells go back to beginning (not all of them will become spermatozoa)
Intercytaplasmic ridges- joined together (have to do things in synchrony)- divide and replicate together

Question 10

Meiosis Phase

Answer 10

2 phases
Cross over and random reassortment of DNA- creates genetic diversity
End up with genetically unique haploid cells
Start of prophase- primary spermatocytes
After prophase- secondary spermatocytes
Prophase relatively long (1/3 of whole process)
After second phase- spermatids- haploid

Question 11

Differentiation phase

Answer 11

Starts with spermatids, ends with spermatozoa
No cell division or replication
Changing from round cell to morphological function
Needs to be able to get through zona pellucida and fertilise ovum- head
Needs to be able to move itself- tail- energy-mitochondria
4 phases
Spermiogenesis
After gets released into lumen

Question 12

4 phases of differentiation phase

Answer 12

Golgi
Cap
Acrosomal
Maturation

Question 13

Spermatozoa structure is ………… in each species

Answer 13

Different

Question 14

Head of spermatozoa

Answer 14

Nucleus and acrosome and post-nuclear gap
Shape varies across species
Acrosome contains hydrolytic enzymes required for penetration of zona pellucida

Question 15

Tail of spermatozoa

Answer 15

Self powered flagellum

Composed of: middle, principle and terminal piece

Question 16

Overall length of spermatozoa

Answer 16

~60um

Question 17

DSO correlates with ………, good measure of …………

Answer 17

Size, fertility

Question 18

Cycle of seminiferous epithelium

Answer 18

How long it takes to go from germ cell (primordial stem cell) to final
1-2 months across species

Question 19

The Spermatogenic wave

Answer 19

Differences at any given instant in time along the seminiferous tubule:
Stage of spermatogenic cycle differs in adjacent regions of tubule
Finite region of tubules releasing sperm at given time
Each section contains different stages of development

Question 20

Endocrine regulation

Answer 20

Hypothalamus releases GnRH to anterior pituitary which releases LH and FSH
LH- leydig cells (intersitial compartment between seminiferous tubules)
Leydig cells produce testosterone (partly influences sertoli cells)
Negative feedback
FSH- sertoli cells

Question 21

What happens in:
The testes
The head and body of the epididymis
The tail of the ejaculation

Answer 21

Spermatozoa Produced
Mature
Stored until ejaculation

Question 22

If male is overworked, fertility …………..

Answer 22

Decreases
Process never speeds up
Ejaculate decreases

Question 23

Clinical relevance

Answer 23

Time for spermatozoa to be produced
Sperm-testis barrier
Semen evaluation

Question 24

What should you record in semen evaluation

Answer 24

Volume, colour, appearance

Question 25

EEJ is more/less dilute than natural service

Answer 25

More dilute

Question 26

Mass motility/wave motion

Answer 26

How many spermatozoa are motile Score 1-5 Low microscope power

Question 27

Scoring of mass motility

Answer 27

``` 5= ~90% active (billowing clouds) 4= 70-80% active (clouds) 3= 45-65% active (fair), more grainy, less cloudy 2= 20-40% active (slow) 1= <20% active (poor) , very slow 0= nothing, all dead ```

Question 28

Progressive motility

Answer 28

How many move in straight line Higher power on microscope Identify 10 separate spermatozoa and see if they are moving straight or in circles Repeat and average to get a proportion that have got progressive motility

Question 29

Gross appearance

Answer 29

Score on how dense it looks Thick creamy, creamy, thin creamy, milky, cloudy, clear watery Careful of pus (makes it look dense)

Question 30

Morphology

Answer 30

Head and tail abnormalities Tail- effects its ability to move progressively Head- effects its ability to get through zona pellucida

Question 31

Head abnormalities

Answer 31

Crater defect Tapered heads Ruffled acrosome Knobbed acrosome

Question 32

Tail abnormalities

Answer 32

Coiled tail Double midpiece Folded tail Detached head

Question 33

Morphology defects

Answer 33

Primary vs secondary | Compensable vs non-compensable

Question 34

Can measure density with........

Answer 34

A Haemocytometer

Question 35

Things spermatozoa are sensitive to

Answer 35

Temperature (cold shock)- keep sample, glassware and staining fluids warm (~37*C) Water Bright light, blood, detergents, cigarette smoke, rubber bung in syringes