homeostasis and response

Question 1

what is homeostasis?

Answer 1

maintaining internal conditions of a cell or organism, in response to internal and external changes

Question 2

what does the body control?

Answer 2

blood glucose concentration
water levels
body temperature

Question 3

what are receptors?

Answer 3

cells which detect stimuli (changes in environment)

Question 4

what do coordination centres do?

Answer 4

they receive and process information from the receptors

Question 5

what do effectors do?

Answer 5

they bring about responses which restore optimum levels.

Question 6

what does the nervous system do?

Answer 6

enables humans to react to their surroundings and coordinate their behaviour.

Question 7

what does the information from receptors pass along as?

Answer 7

cells(neurones) as electrical impulses to the cns

Question 8

what is the CNS?

Answer 8

the brain and spinal cord

Question 9

what does the CNS do?

Answer 9

coordinates the response of effectors which may be muscles contracting or glands secreting hormones.

Question 10

reflex actions

Answer 10

automatic and rapid responses which dont involve the conscious part of the brain

Question 11

what does the brain do?

Answer 11

control complex behaviour

Question 12

what are the 4 main areas of the brain?

Answer 12

cerebellum
cerebrum
medulla
hypothalamus

Question 13

cerebellum

Answer 13

controls balance,coordination of movement and muscular activities

Question 14

cerebrum

Answer 14

split into two hemispheres and is highly folded.controls intelligence,personality, conscience and high level functions

Question 15

medulla

Answer 15

controls unconscious activities

Question 16

hypothalamus

Answer 16

the regulating centre for the temperature and water balance within the body

Question 17

what is the endocrine system?

Answer 17

its composed of glands which secrete chemicals (hormones) into the bloodstream

Question 18

what does the pituitary gland do?

Answer 18

secretes hormones in response to body conditions.(some of the hormones act on other glands to stimulate other hormones)

Question 19

adrenaline

Answer 19

produced by adrenal glands during times of fear or stress.
prepares the body for fight or flight

Question 20

thyroxine

Answer 20

produced by the thyroid gland.
increases metabolic rate,controls growth and development in young animals.
controlled by negative feedback

Question 21

blood glucose concentration

Answer 21

monitored and controlled by the pancreas

Question 22

responses to high blood glucose concentration?

Answer 22

-the pancreas produces more insulin(insulin causes the blood to move from the blood into the cells.
-the excess insulin in liver and muscles is converted to GLYCOGEN for storage.

Question 23

responses to low blood glucose concentation?

Answer 23

-the pancreases releases GLUCAGON
-GLUCAGON stimulates GLYCOGEN to be converted into glucose and be released into the blood.

Question 24

type 1 diabetes

Answer 24

-caused from the pancreas not producing enough insulin.
-results in uncontrolled high blood glucose levels which are treated with insulin injections.

Question 25

type 2 diabetes

Answer 25

-caused from the body not responding to insulin.
-obesity is a risk factor
-treated with a healthy diet and regular exercise

Question 26

how does water leave body?

Answer 26

via the lungs during exhilation

Question 27

what is lost from the skin in sweat?

Answer 27

-water
-ions
-urea

Question 28

there is no control over…

Answer 28

water, ions or urea loss by lungs or skin

Question 29

excess … are removed via … in the …

Answer 29

-water, ions and urea
-the kidneys
-the urine

Question 30

what happens if body cells lose or gain too much water by osmosis?

Answer 30

they don’t function efficiently

Question 31

what does the digestion of proteins from food result in?

Answer 31

excess amino acids

Question 32

in the liver what happens because of this?

Answer 32

excess amino acids are converted to ammonia in a process called DEAMINATION

Question 33

ammonia is ?

Answer 33

toxic so its converted to urea for safe excretion.

Question 34

the kidneys produce urine by:

Answer 34

-filtering the blood
-selective reabsorption of useful substances (glucose,ions,water)

Question 35

what are water levels in the body controlled by?

Answer 35

ADH

Question 36

ADH?

Answer 36

-released by the pituitary gland when the blood is too concentrated
-it passes in the blood, to the kidney tubules where it causes more water to be reabsorbed back into the blood.(controlled by NEGATIVE FEEDBACK)

Question 37

kidney failure

Answer 37

-treated by organ transplant or kidney dialysis

Question 38

dialysis

Answer 38

-a machine which takes over the role of the kidneys
-used to remove waste products from the blood
(3x a week)

Question 39

oestrogen

Answer 39

the main female reproductive hormone produced in the ovary.

Question 40

ovulation

Answer 40

when eggs begin to mature and one is released
approximately every 28 days.

Question 41

testosterone

Answer 41

the main male reproductive hormone produced by the testes and it stimulates sperm production.

Question 42

Follicle stimulating hormone

Answer 42

causes maturation of an egg in the
ovary

Question 43

Luteinising hormone

Answer 43

stimulates the release of the egg

Question 44

Oestrogen and progesterone

Answer 44

involved in maintaining the uterus
lining.

Question 45

3 hormonal and non hormonal forms of contraception

Answer 45

oral contraceptives( contain hormones to inhibit FSH production so that no eggs mature)
injection, implant or skin patch ( slow release progesterone to inhibit the maturation and release of eggs for months or years)
barrier methods( condoms and diaphragms which prevent the sperm reaching an egg)

Question 46

doctors may give..

Answer 46

FSH and LH in a ‘fertility drug’ to a woman. She
may then become pregnant in the normal way.