B5-Homoeostasis and response

Question 1

What is homoeostasis

Answer 1

Maintaining a stable internal environment

Question 2

What does negative feedback do and what examples

Answer 2

Negative feedback counteracts changes – if something gets too high or too low your body is negative feedback to be back to normal

Glucose regulation, Body temperature, water levels

Question 3

How does the central nervous system coordinate a response

Answer 3

Stimulus – receptor – sensory neurone – central nervous system – motor neurone – Effecter-Response

Question 4

What is a synapse

Answer 4

The connection between two neurons

Question 5

What is the reflex arc

Answer 5

Stimulus – receptor – sensory neurone – Relay neuron – motoneuron – affecter

This Important because The automatic and rapid response which doesn’t involve the conscious part of the brain prevents injury

Question 6

Where are there: pituitary gland, Thyroid,ovaries, adrenal gland, testes, pancreas

Answer 6

The pituitary gland: brain
thyroid: Neck
Ovaries: been ovaries
Adrenal gland: near the pancreas
Pancras: pancreas
Testes: testes

Question 7

What is the endocrine system

Answer 7

The composition of glands which Secrete chemicals called hormones directly into the bloodstream

Question 8

What is the difference between a nerve and a hormone

Answer 8

Nerves are very fast, act for a very short time, Act on a very precise
area

Hormones are slow, act for a long time, act in a more general way

Question 9

The control of Blood glucose concentration

Answer 9

Its bloody Glucose levels are too high the pancreas produces the hormone insulin which causes glucose to move from the blood into the cells –E.g. the liver where is change to glycogen For storage

When there is not Enough glucose in the blood the pancreas releases glucagon which stimulates the release of glucose from the liver which raises blood glucose levels

She’s done for negative feedback

Question 10

What is type one diabetes

Answer 10

Where the pancreas produces little or no insulin meaning that the person has no control over their blood glucose levels

Treated with insulin injections

Question 11

What is Type 2 diabetes

Answer 11

And when the body cells no longer respond to insulin produced by the pancreas

Question 12

What is FSH, Where is it made and what does it stimulate

Answer 12

Causes the egg to mature

There pituitary gland

Stimulates oestrogen

Question 13

What is oestrogen, Where is it made and what does it inhibit/stimulate

Answer 13

Causes the lining of the uterus to grow

Ovaries

Stimulates LH and inhibits FSH

Question 14

Where is LH made and what does it do

Answer 14

Pituitary land

Stimulates the release of the egg

Question 15

Where is progesterone made, What does it do and what does it inhibit

Answer 15

Ovaries

It maintains the lining of the uterus during the second half of the cycle – when progesterone levels for the lining breaks down

It inhibits the release of LH and FSH

Question 16

What is the order of the hormones in the menstrual cycle

Answer 16

FSH – causes egg to mature
*Stimulates the ovaries to produce oestrogen

Oestrogen – causes lining of uterus to grow
*Stimulates LH and inhibits FSH

LH-Stimulates the release of an egg

Progesterone – maintains the lining of the uterus during the second half the cycle and when levels of progesterone falls The lining breaks down
*Inhibits the release of FSH and LH

Question 17

What are the hormonal ways of controlling fertility

Answer 17

– oestrogen/progesterone
– the pill – contains oestrogen and progesterone
– the Contraceptive patch – contains oestrogen and progesterone (it’s stuck into the skin and last week)
– the contraceptive injection(Contains progesterone and lasts around 2 to 3 months
– IUD-A T shape device that is inserted into the uterus to kill sperm and prevent implantation of a fertilised egg (contains progesterone)

Question 18

Barrier methods of contraception

Answer 18

Condom
– die for again – a shallow plastic cup that fits in the cervix (it’s a barrier and also contain spermicide which kills sperm)
– spermicide can be used alone

Question 19

What are those drastic ways of avoiding pregnancy

Answer 19

– Sterilisation

– avoiding intercourse

Question 20

How do you fertility drugs work

Answer 20

They contain FSH which cause more eggs to mature in ovary and also triggers oestrogen production – LH is then given to stimulate the release of the egg

*Can always work/could cause multiple births

Question 21

How does IVF work

Answer 21

It involves collecting multiple eggs from the woman’s ovaries and fertilising them in a Lab With a male sperm –Some of the fertilised eggs Are then planted into the woman’s uterus and others are frozen for later use

Question 22

Disadvantages of IVF

Answer 22

They can cause multiple births, it’s expensive and the success rate is low, it can be stressful and upsetting

Question 23

Why are people against IVF

Answer 23

It often results in a news embryos are destroyed, people think it’s unethical because each and we have potential human life – the genetic testing of embryos before implantation also raises ethical issues about some people think it could lead to the selection of preferred characteristics

Question 24

What is adrenaline

Answer 24

Hormonal which is released in response to stressful and scary situations – your brain detects the fear of stress and says nervous impulses to the adrenal glands which respond by secreting Adrenaline

This gets your body ready for “fight or flight “by triggering mechanisms increase supply of oxygen and glucose to the cells in the brain muscles

Question 25

Thyroxine regulate metabolism:

Answer 25

It plays an important role in regulating the basic metabolic rate-Speed at which reactions in the body occur while the body is at rest

Negative feedback system keeps the right amount of thyroxine in the blood the right level – if it’s too high secretion is inherited and if it’s too low it’s inhibited