Male Reproductive system

Question 1

Parts of the Male Reproductive System

Answer 1

Testes
Epididymis
Vas Deferens 
Urethra
Penis
Prostate Gland
Os Penis (dog)
Bulbourethral Gland (Accessory gland in Tomcat)

Question 2

Testes

Answer 2

Oval shaped structure wrapped in a double layer of peritoneum.
Function:
- To produce sperm by the process spermatogenesis.
- To produce fluid to transport sperm from the testes into the female tract.
- To secrete testosterone, influences spermatogenesis .
Testes are descended by 6 weeks in a dog.
Extends from testes to scrotum through inguinal canal.
During foetal development, the cord shortens.
Testes are drawn into scrotum during development in the canine.
In the dog, scrotum lies between the hind legs.
In the tomcat, is attached to the perineum, ventral to the anus.

Question 3

Cryptorchid/ Monorchid

Answer 3

Testes fail to descend
If retained in abdominal cavity, spermatogenesis is inhibited due to the higher temperature of the testes being inside the body.
There is an increased of testicular tumours in these cases.

Question 4

Sertoli Cells

Answer 4

Controlled by FSH and Testosterone.
Two- way communication between Sertoli and Leydig cells.
Growth hormones may also have some regulatory function on Sertoli cells.
The quantity of Sertoli cells present directly correlates with the amount of sperm produced.

Question 5

Epididymis

Answer 5

Long, convoluted tubule.
Connects efferent ducts of testis to Vas Deferens.
Head (caput)- At end where blood/nerves enter.
Body (Corpus)- Parallels long axis of testes.
Tail- Double back as Vas Deferens.

Question 6

Vas Deferens

Answer 6

AKA deferent duct or ductus deferens.
Passes out of the scrotum into the abdominal cavity.
During ejaculation, sperm and the fluid produced in the seminiferous tubules are propelled along the epididymis and up the vas deferens which join the urethra.
A the junction the walls of the Vas Deferens are thickened and glandular.
- The whole ares is surrounded by the prostate gland.

Question 7

The Urethra

Answer 7

Runs through the centre of the penis and extends from the bladder to the tip of the penis.
Shared by both the reproductive and urinary systems.

Question 8

The Penis (dog)

Answer 8

Urethra lies in the centre, surrounded by a layer of cavernous erectile tissue.
This is expanded into the bulb of the penis and, towards the tip as the glans penis.
Glans Tissue- tunnel shaped bone, function is to aid entry of the penis into the vagina of the bitch.

Question 9

The Penis (Tomcat)

Answer 9

Main parts of penis are similar to dog.
Cat penis is shorter and points backwards.
Glans penis is covered in tiny barbs - elicits a pain reflex as the male withdraws from the female after mating.
Stimulates nerve pathway to the hypothalamus.
Os penis lies ventral to the urethra in the cat.
During sexual excitement, the penis engorges and points cranioventrally so that the mating position in cats is similar to that of dogs.

Question 10

Accessory Glands

Answer 10

Function:
- To secrete seminal fluids which provided the correct environment for sperm survival.
2 types of gland related to this system.
  - Prostate Gland
  - Bulbourethral Glands

Question 11

Prostrate Gland

Answer 11

Bi- lobed and lies on the floor of the pelvis surrounding the urethra.
In the dog, lies at the neck of the bladder at the start of the urethra.
In the cat, lays a little further down the urethra.
About the size and shape of a peeled walnut and completely surrounds the urethra.
In older animals the prostate can become enlarged and block the urine flow

Question 12

Bulbourethral Glands

Answer 12

Are only found in the cat and not in the dog.
Situated further down the urethra.
Like the prostate, these make a contribution to seminal fluid.