Male Reproduction

Question 1

What is the position and structure of the scrotum?

Answer 1

It is a pouch of pigmented skin, fibrous tissue and muscle, divided into two compartments containing:

• a testis
• an epididymis and testicular end of the spermatic cord

Question 2

What are the three layers of the testes?

Answer 2

Outside: TUNICA VAGINALIS - outer covering of membrane formed from peritoneum

Middle: TUNICA ALBUGINEA - fibrous covering forming the septa which divides the testes into lobes, to localise function

Inside: TUNICA VASCULOSA - network of capillaries

Question 3

How many lobules are there in a teste?

Answer 3

200-300

Question 4

What is the role of 5the seminiferous tubules?

Answer 4

This is where spermatozoa is functionally creased

Convoluted loops of germinal epithelium

Question 5

What are the LEYDIG cells?

Answer 5

Ells which lie between the seminiferous tubules, which produce testosterone after puberty

Question 6

What is the EPIDIDYMIS?

Answer 6

A single highly convoluted tubule forming a mass at the upper pole of the testes

Question 7

What is the VAS DEFERENS?

Answer 7

A duct formed from the epididymis as it leaves the scrotum in the spermatic cord

Question 8

What is the SPERMATIC CORD?

Answer 8

Suspends the testes in the scrotum and contains the vas deferens, blood and lymph vessels and nerves

Question 9

What is the blood supply of the testes

Answer 9

Testicular arteries and veins

Question 10

What is the nerve supply of the testes

Answer 10

10/11th thoracic nerves

Question 11

Describe the structure and function of the seminal vesicles?

Answer 11

These are two fibromuscular pouches, 5cm long which lie posterior at the base of the bladder

They are joined to the VAS DEFERENS by a small duct which then joins the urethra

Secretes seminal fluid

Question 12

What is the role of seminal fluid?

Answer 12

ALKALINE; neutralises acidic environment of the female reproductive tract at intercourse
Provides energy for sperm
Assists in coagulation of the semen after intercourse

Question 13

What is Spermatogonia is

Answer 13

The formation 9f male gametes

Question 14

What part of spermatogenesis occurs in fetal development?

Answer 14

Primordial germ cells differentiate into Spermatogonia which remain dormant until puberty

Question 15

Describe spermiogenesis

Answer 15

The spermatogonium stem cells divide via mitosis to produce primary spermatocytes. This then divides into a pair of haploid secondary spermatocytes via Meiosis I, which then divide further into four haploid spermatids in Meiosis II. These undergo spermiogenesis to become functioning sperm cells

Question 16

What is the path of the sperm cell into the ova in fertilisation?

Answer 16

Corona radiate > Zona pellucida > plasma membrane of secondary oocyte > cytoplasm of secondary oocyte

Question 17

Describe the stages of fertilisation?

Answer 17

Once sperm is deposited, the sperm that reaches the oocyte undergoes capacitation once in the uterine tubes

The acrosome releases hydrolytic hylauronidase enzymes via exocytosis. These disperses the corona radiata to allow access to the zona pellucida (acrosomal reaction)

The zona pellucida is penetrated by the first sperm that reaches it, and the oocyte membrane fuses with the spermatic cell membrane

The sperm cell looses its tail

The oocyte completes meiosis II, and the gametes fuse, becoming a diploid zygote