UNIT 2 - KA2

Question 1

What are hormones

Answer 1

Hormones are chemical messengers that are secreted into the bloodstream

Question 2

What happens when a hormone reaches its specific target tissue

Answer 2

When a hormone reaches its specific target tissue it brings about a specific effect

Question 3

What do hormones control

Answer 3

Hormones control the onset of puberty, sperm production and the menstrual cycle

Question 4

What happens at the onset of puberty

Answer 4

At the onset of puberty, the hypothalamus produces a releaser hormone which targets the pituitary gland

Question 5

What happens as a result of the hypothalamus producing releaser hormones

Answer 5

As a result the pituitary glands is stimulated to produce two hormones

Question 6

What two hormones does the pituitary gland produce

Answer 6

• follicle stimulating hormone (FSH)
• interstitial cell stimulating hormone (ICSH) in men and luteinising hormone (LH) in women

Question 7

What are the hormones released by the pituitary gland responsible for triggering

Answer 7

These hormones are responsible for triggering sperm production in men and menstruation in women

Question 8

What does FSH stimulate the production of in males

Answer 8

FSH stimulates the production of sperm in the seminiferous tubules in the testes

Question 9

What does ICSH Stimulate the production of in men

Answer 9

ICSH stimulates the production of testosterone in the interstitial cells in the tests

Question 10

The role of testosterone ) - i

Answer 10

It stimulates the production of sperm in the seminiferous tubules

Question 11

The role of testosterone ) - ii

Answer 11

It stimulates the seminal vesicles and prostate gland to produce their secretions

Question 12

The role of testosterone ) - iii

Answer 12

at high concentrations it inhibits the secretion of FSH and ICSH by the pituitary gland

Question 13

What is the inhibition of the pituitary gland by testosterone an example of

Answer 13

This inhibition of the pituitary gland by testosterone is an example of negative feedback control

Question 14

What is the release of the hormone testosterone back to the pituitary gland an example of

Answer 14

Hugh concentration of testosterone - this is an example of negative feedback control

Question 15

What does high levels of testosterone cause inhibition of

Answer 15

Testosterone is under negative feedback control. High levels of testosterone cause inhibition of the pituitary gland which reduces the secretion of FSH and ICSH which in turn reduces the levels of testosterone

Question 16

How many days approximately are in the menstrual cycle

Answer 16

The menstrual cycle takes approximately 28 days with the first day of menstruation regarded as day one

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Question 17

What are the four hormones directly involved with the control of the menstrual cycle

Answer 17

• the pituitary hormones FSH and LH
• the ovarian hormones oestrogen and progesterone

Question 18

What do the releaser hormones do

Answer 18

The releaser hormones from the hypothalamus stimulate the secretion of FSH and LH from the pituitary gland

Question 19

What 2 hormones are produced by the pituitary gland in women

Answer 19

• follicle stimulating hormone
• luteinising hormone

Question 20

What is the role of FSH in women

Answer 20

• stimulates the development of the follicle
• stimulates the follicle to produce oestrogen

Question 21

What is the role of LH in women

Answer 21

• surge in LH triggers ovulation
• follicle develops into corpus luteum
• corpus luteum secretes progesterone

Question 22

What is the first ovarian hormone produced

Answer 22

Oestrogen

Question 23

What is the second ovarian hormone produced

Answer 23

Progesterone

Question 24

When is progesterone secreted

Answer 24

Secretion of progesterone after ovulation

Question 25

What is the effect of secretion of oestrogen

Answer 25

Secretion of oestrogen stimulates the production of LH by pituitary

Question 26

What are the two effects of oestrogen on the uterus and pituitary gland

Answer 26

- oestrogen stimulates the proliferation of the endometrium - oestrogen stimulates the secretion of LH by the pituitary gland

Question 27

How does oestrogen effect the uterus

Answer 27

Oestrogen stimulates proliferation (thickening due to cells dividing) of the endometrium ( inner layer of the uterus) in preparation for implantation of embryo

Question 28

How does oestrogen effect the pituitary gland

Answer 28

Oestrogen also stimulates the secretion of LH by the pituitary gland

Question 29

What is the first stage of the menstrual cycle (follicular phase

Answer 29

FSH stimulates the development of a follicle and the production of oestrogen by the follicle in the follicular phase

Question 30

What is the second stage of the menstrual cycle

Answer 30

Oestrogen stimulates proliferation of the endometrium preparing it for implantation and affects the consistency of the cervical mucus making it more easily penetrated by sperm. Peak levels of oestrogen cause a surge in the secretion of LH. This surge in LH triggers ovulation

Question 31

What is the third stage of the menstrual cycle

Answer 31

In the luteal phase the follicle develops into a corpus luteum which secretes progesterone. Progesterone promotes further development and vascularisation of the endometrium preparing it for implantation if fertilisation occurs

Question 32

What is the last stage of the menstrual cycle

Answer 32

The negative feedback effect of the ovarian hormones on the pituitary gland and the secretion of FSH and LH prevent further follicles from developing. The lack of LH leads to the degeneration of the corpus luteum with a subsequent drop in progesterone levels leading to menstruation

Question 33

What is ovulation

Answer 33

Ovulation is the release of an age (ovum) from a follicle in the ovary. It usually occurs around the mid point of the menstrual cycle

Question 34

What happens if fertilisation does occur

Answer 34

If fertilisation does occur the corpus luteum does not degenerate and progesterone levels remain high

Question 35

What is proliferation

Answer 35

Proliferation is the thickening of the inner lining of the uterus due to cells dividing

Question 36

What is vascularisation

Answer 36

Vascularisation is thickening due to cells becoming bigger into a spongy layer rich in blood vessels

Question 37

What does the lack of LH cause

Answer 37

The lack of LH leads to degeneration of the corpus luteum with a subsequent drop in progesterone levels leading to menstruation

Question 38

What are the two effects of progesterone on the uterus and pituitary gland

Answer 38

- progesterone promotes vascularisation of endometrium - progesterone inhibits the secretions of FSH and LH by the pituitary gland

Question 39

What is the effect of progesterone on the uterus

Answer 39

- progesterone promotes vascularisation of the endometrium into a spongy layer rich in blood vessels for embryo implantation if fertilisation occurs

Question 40

What is the effect of progesterone on the pituitary gland

Answer 40

Progesterone inhibits the secretions of FSH and LH by the pituitary gland

Question 41

How does the negative feedback control raise the concentration of testosterone if it has fallen to a low level

Answer 41

- low levels of testosterone fails to inhibit the pituitary gland - an increased concentration of ICSH is released by thr pituitary gland - interstitial cells produce testosterone