2.1 The structure & function of reproductive organs and gametes & their role in fertilisation. Hormonal Control of reproduction

Question 1

What are the testes?

Answer 1

site of sperm production and the male sex hormone testosterone.

Question 2

What is the male sex hormone?

Answer 2

testosterone.

Question 3

What are sperm and what and where are they formed from?

Answer 3

male gametes and they are formed germline cells by meiosis in tubules called seminiferous tubules

Question 4

What do seminiferous tubules come together to form ?

Answer 4

coiled tubules that connect to the sperm duct.

Question 5

How do sperm leave the testis?

Answer 5

via sperm duct

Question 6

Where are interstitual cells located and what do they do?

Answer 6

in the tissue between the seminiferous tubules and produce testosterone

Question 7

What is testosterone directly passed into?

Answer 7

the bloodstream

Question 8

What does testosterone do?

Answer 8

stimulate sperm production and also brings about the development of male secondary sexual characteristics

Question 9

When are sperm released into the vagina?

Answer 9

during sexual intercourse

Question 10

What are sperm which allow them to travel to the egg?

Answer 10

they are motile

Question 11

As sperm are motile what are they able to move through?

Answer 11

the uterus and along the oviducts where they may meet an egg and fertilise it

Question 12

What do sperm require?

Answer 12

a fluid medium and a source of energy

Question 13

Name 9 main parts of the male reproductive organs?

Answer 13

penis
opening of urethra
urethra 
testes
scrotum 
sperm duct 
prostate gland
seminal vesicle 
bladder

Question 14

Name the 2 accessorary glands in the male reproductive system?

Answer 14

seminal vesicles and prostate gland.

Question 15

What do seminal vesicles do?

Answer 15

secrete liquid rich in fructose and hormone-like compounds called PROSTAGLANDINS.

Question 16

What ways does fructose contribute to fertilisation?

Answer 16

sugar provides sperm with energy needed for motility following their relax at ejaculation

Question 17

What ways do prostaglandins contribute to fertilisation?

Answer 17

stimulate contractions of the female reproductive tract . These movements help sperm reach the oviduct at a faster rate than could be achieved by swimming alone

Question 18

What does the prostate gland do?

Answer 18

sectretes a thin, lubricating liquid containing enzymes

Question 19

What ways do enzymes contribute to fertilisation?

Answer 19

maintains the fluid medium at the optimum viscosity for sperm mobility

Question 20

What makes up semen?

Answer 20

sperm
liquid rich in fructose and prostaglandins
thin lubricating liquid containing enzymes

Question 21

Name the 6 main parts of the female reproductive organs?

Answer 21

vagina
cervix
uterus
endometrium
oviduct
ovaries

Question 22

What is the female gametes?

Answer 22

ova (eggs)

Question 23

What is ova formed from and where?

Answer 23

by germline cells by meiosis in the ovaries

Question 24

At birth, what do female’s ovaries contain?

Answer 24

immature ova in various stages of development

Question 25

What is each ovum surrounded by?

Answer 25

a follicle

Question 26

What does the follicle do?

Answer 26

protect the developing ovum and secretes oestrogen

Question 27

What is ovulation?

Answer 27

release of an egg

Question 28

What happens during ovulation?

Answer 28

mature ova are released into the oviduct, the old follicle develops into the corpus luteum which secretes progesterone and some oestrogen

Question 29

What is the first phase of the development of ova and how long does it usually last?

Answer 29

follicular phase
DAY 1-14.
Ovulation is aroundday 14.
Immature ovum develops into mature ovum

Question 30

What is the second phase of the development of ova?

Answer 30

Luteal Phase
After ovulation, old follicle develops into corpus luteumwhich secretes progesterone and some oestrogen and then degeneates

Question 31

What happens after the sperm enters the cytoplasm of the egg?

Answer 31

a reaction takes place, preventing other sperm from fertilising the same egg

Question 32

What happens during fertilisation?

Answer 32

the sperm’s nucleus then fuses with the nucleus of the ovum.

Question 33

What is the first cell of the new individual called?

Answer 33

zygote (diploid)

Question 34

Following successful fertilisation, what does the zygote do?

Answer 34

move along the oviduct towards the uterus.

Question 35

What happens to the zygote as it travels?

Answer 35

it undergoes a series of mitotic divisions (i.e. cleavage) to increase cell number (but not size)

Question 36

What is cleavage?

Answer 36

special division where cells divide without an increase in cytoplasm

Question 37

By the time the zygote arrives at the uterus what has it become?

Answer 37

a ball of cells called a blastocyst

Question 38

What does the blastocyst do?

Answer 38

implants into the endometrium where it will continue to develop.