Pre-fertilisation events

Question 1

During coitus which animals have sperm deposited directly into the vagina?

Answer 1

Sheep, bovine and dog.

Question 2

During coitus which animals have sperm deposited directly into the uterus?

Answer 2

Horse, pig and camelids.

Question 3

What aids creates the movement of the flagellum tail of sperm?

Answer 3

The central Axoneme and and Dyneins

Question 4

Where does sperm mature and how long does it stay in this place on average?

Answer 4

The epididymus and 1-2 weeks

Question 5

What role does seminal plasma play in the female repro tract?

Answer 5

Transport medium
Nutritional support
Contains fructose used by sperm for energy (sorbitol)
Buffering capacity (female tract can be quite acidic)
Antioxidants (Ascorbic acid)
Proteins bind to sperm head to protect it in female tract.
Prostaglandins from prostate gland.

Question 6

Sialomucin (low viscosity) and sulphomucin (high viscosity) are two secretions from the cervix what are their functions?

Answer 6

Removal of non-motile sperm.

Spermatozoa reservoir.

Question 7

What do the three fractions of a canine ejaculate contain?

Answer 7

1st: seminal plasms 2nd: sperm rich 3rd: seminal plasma

Question 8

What is capacitation and what does it allow?

Answer 8

Capacitation is a functional maturation of the spermatozoon. The changes take place via the sperm cell membrane in which it may be that receptors are made available through the removal of a glycoprotein layer. The area of the acrosomal cap is also so altered thereby that the acrosome reaction becomes possible.
Through the membrane alterations, the motile properties of the spermatozoon also change. Discharging whipping movements of the tail together with larger sideways swinging movements of the head take place. This type of motility is designated as hyperactivity. One can therefore say that the visible consequences of capacitation consist in hyperactivity of the spermatozoon.

Question 9

When does capacitation happen?

Answer 9

Between ejaculation and within the female genital tract.

Question 10

What initiates the acrosome reaction?

Answer 10

Sperm binding to the zona pellucida.

Question 11

What induces completion of meiosis 1 in the oocyte?

Answer 11

Ovulation

Question 12

What induces completion of me meiosis 2 in the oocyte?

Answer 12

sperm binding to oocyte induces and influx of calcium ions which induces completion of meiosis 2.

Question 13

What are the key stages of pre-fertilisation sperm events?

Answer 13

1. Transverse thecervix
2. Transport through uterus to oviduct
3. Oviductal storage
4. Capacitation
5. Bind to the oocyte
6. Acrosome reaction
   - Penetrate zona pellucida
7. Fusion of nuclei