Hormones and effects (topic 7)

Question 1

What is a hormone?

Answer 1

A chemical which is secreted from a gland to a target organ to regulate processes

Question 2

what is thyroxine?

Answer 2

Thyroxine is a hormone which is secreted by the thyroid gland and targets the heart, lungs liver,digestive systems and brain. It increases the METABOLIC RATE which is
the rate at which cells respire or convert glucose to energy.

Question 3

Where is the pituitary gland and what does it secrete?

Answer 3

Found in the brain and releases ADH, FSH and LH

Question 4

What is ADH and what does it do?

Answer 4

Anti diuretic hormone

It stimulates the reabsorption of water in the kidneys, specifically the collecting tube.

Question 5

What is FSH and what does it do?

Answer 5

Follicle stimulating hormone

It stimulates the development/maturation of the egg inside the follicle and stimulates production of oestrogen.

Question 6

What Is LH and what does it do?

Answer 6

Luteinising hormone

It stimulates ovulation (releasing the egg) and progesterone secretion.

Question 7

What is Oestrogen and what does it do?

Answer 7

It controls puberty and the menstrual cycle
It stimulates production of LH and suppresses the production of FSH in the pituitary gland.#
It thickens the Uterus lining

Question 8

What is progesterone and what does it do?

Answer 8

Maintains the lining of the womb (when there is a yellow body because the egg needs the uterus lining) - suppresses FSH production in the pituitary gland.

Question 9

What is a yellow body?

Answer 9

A follicle when the egg has been released.

Question 10

Where are oestrogen and progesterone secreted from?

Answer 10

The ovaries
oestrogen from the yellow body
Progesterone from the follicle

Question 11

What is IVF?

Answer 11

IN vitro fertilisation

When the egg is fertilised outside the women’s body and implanted back into her uterus

Question 12

What are the ethical issues with IVF?

Answer 12

left over embryos are killed and increased chances of multiple births

Question 13

What is negative feedback?

Answer 13

When the body activates responses in order to return a condition to its normal state e.g normal temperature by vasodilation

Question 14

How does a temperature increase cause the kidneys to reabsorb more water?

Answer 14

When temperature increases, the hypothalamus loses water to the blood vie osmosis and crenates. when the hypothalamus crenates, ADH secreted and targets the kidneys, causing it to reabsorb more water from the urine, decreasing the amount of urine created.

Question 15

What processes are performed by the nephron?

Answer 15

Ultra filtration - happens at the glomerulus
Osmoregulation - controls balance of water and salts
Selective re absorption

Question 16

What are the disadvantages of treating infertility by using hormones to stimulate ovulation?

Answer 16

Because the treatment (FSH and LSH hormones) boosts the production of mature eggs, too many eggs could be fertilised, multiple conceptions sometimes occur, with twins or triplets being expected. This increases the risk of complications in pregnancy and childbirth, and may lead to premature or underweight babies.

Question 17

What hormone prevents ovulation?

Answer 17

Progesterone

Question 18

Why will an underactive thyroid gand increase a persons body mass?

Answer 18

Because an underactive thyroid gand will secrete less thyroxine, decreasing your metabolic rate. This means that less glucose is converted into energy and therefore more is stored as fat.

Question 19

What are hormones?

Answer 19

They are a chemical messengers which are secreted by endocrine glands. They travel around the body until they reach their target organ causing it to react and change.

Question 20

What does the piuitary gland secrete?

Answer 20

TSH, ADH , FSH and LH

Question 21

What does the hypothalamus secrete?

Answer 21

TRH

Question 22

What does the thyroid gland secrete?

Answer 22

Thyroxine

Question 23

What does the pancreas secrete?

Answer 23

insulin and glucagon

Question 24

What gland secretes adrenalin?

Answer 24

adrenal

Question 25

What do the ovaries secrete?

Answer 25

oestrogen and progesterone

Question 26

What is TRH?

Answer 26

Thyrotropin-releasing hormone
A Homone secreted from the hypothalamus when it detects a change (e.g. low thyroxine) and targets the pituitary gland stimulating the release of TSH.

Question 27

What is TSH

Answer 27

Thyroid stimulating gland

A hormone secreted from the pituitary gland which stimulates the thyroid gland to produce thyroxine.

Question 28

How is TRH and TSH used to reduce levels of thyroxine and reduce your rate of metabalism back to normal levels?

Answer 28

If there is an increase in thryoxine, the metabolic rate will increase. The hypothalamus detects the decrease of glucose in the blood and inhibits the production of TRH. The lack of TRH means it stimulates the piutary gland to secrete less TSH. With less TSH, it stimulates the thyroid gland to secrete less thyroxine.
Now that there is less thyroxine, the metabolic rate is no longer being increased and therefor begins to fall back down to a normal level.
The thyroxine also inhibits the secretion of TRH and TSh so there for with less thyroxine, more TRH and TSH is secreted bringing thryoxine levels back up to normal.

Question 29

How is TRH and TSH used to Increase levels of thyroxine and reduce your rate of metabalism back to normal levels?

Answer 29

If there has been a DECREASE in thryoxine, the metabolic rate will DECREASE. The hypothalamus detects the INCREASE of glucose in the blood and stimulates the production of TRH. The increase of TRH means it stimulates the piutary gland to secrete MORE TSH. With MORE TSH, it stimulates the thyroid gland to secrete MORE thyroxine.
Now that there is more thyroxine, the metabolic rate is going to be increased and therefor begins to climb back to a normal level.
The thyroxine also inhibits the secretion of TRH and TSh so there for with more thyroxine, less TRH and TSH is secreted bringing thryoxine levels back down to normal.

Question 30

What happens in week 1 of the menstrual cycle?

Answer 30

Menstruation occurs, beginning on day 1 and usually lasts 5 days.
Low levels of LH due to low levels of oestrogen. Low levels of oestrogen and progesterone cause menstruation. The Low levels of progesterone allows for FSH to be released and begin maturing a second egg.

Question 31

What happens in the beginning of week 2 of the menstrual cycle?

Answer 31

The lining of the uterus is gradually built up.
Oestrogen levels increase because a matured follicle secretes oestrogen which then builds the uterus lining. Oestrogen levels cause the FSH levels to reduce. It also causes LH to increase a lot which stimulates ovulation.

Question 32

What happens in the end of week 2 of the menstrual cycle?

Answer 32

Ovulation

The High levels of LH stimulate it.

Question 33

What happens during Week 3 of the menstrual cycle?

Answer 33

As the follicle becomes a yellow body, progesterone is secreted. This cause FSH and LH to be inhibited and the uterus lining to be maintained. The oestrogen still thickens the lining.

Question 34

What happens towards the end of week 4 of the menstrual cycle?

Answer 34

If the eg is not fertilised, the yellow body (corpus luteum) begins to break down, and the progesterone concentration falls (menstruation) allowing for FSH to be released again.

Question 35

What is the affect of adrenalin?

Answer 35

Brings about the fight or flight response

• increases heart rate
• constricts and dilates blood vessels to divert blood flow to muscles.