Homeostasis

Question 1

What is homeostasis?

Answer 1

Maintaining a stable internal environment

Question 2

How does the body maintain homeostasis?

Answer 2

Negative feedback mechanisms

Question 3

Examples of homeostasis?

Answer 3

Temperature, blood glucose, hormones

Question 4

Cold temperature outside?

Answer 4

Thermoreceptors detect body temperature is too cold
Thermoregulatory centre
effects:
Hair goes up to trap warm air
surface blood vessels vasoconstrict so that the blood is closer to your body
excessive rapid muscle contractions to keep warm

Question 5

Warm temperature outside?

Answer 5

Thermoreceptors detect body temperature is too hot
Thermoregulatory centre
effects:
surface blood vessels vasodilator so that the blood is closer to your surroundings so that heat can escape from radiation
you sweat which takes heat by evaporation

Question 6

Ideal core body temperature

Answer 6

37 degrees

Question 7

What is a hormone?

Answer 7

Chemical molecule released into the blood
produced by glands
part of the endocrine system

Question 8

What makes up the endocrine system?

Answer 8

Pituitary gland
thyroid
adrenal gland
pancreas
ovaries/testes

Question 9

Action of nerves?

Answer 9

Fast
short acting
precise area

Question 10

Action of hormones?

Answer 10

slower
longer acting time
general area

Question 11

High blood glucose?

Answer 11

insulin released
glucose moves into muscles and liver
stored in liver as glycogen
decrease in blood glucose

Question 12

Low blood glucose?

Answer 12

glucagon released
liver breaks down glycogen
increase in blood glucose

Question 13

What is type 1 diabetes?

Answer 13

Genetic

body doesn’t make insulin

Question 14

What is type 2 diabetes?

Answer 14

obesity

body doesn’t respond to insulin anymore

Question 15

What are the kidneys?

Answer 15

Part of the endocrine system
filter the blood
produces urine

Question 16

What is urea?

Answer 16

excess amino acids are converted into fats and carbohydrates in the liver
ammonia is produced as a waste product
ammonia is converted to urea by liver
urea transported to kidney to be filtered by the nephrons

Question 17

Why change ammonia to urea?

Answer 17

Ammonia is toxic

Question 18

Why change excess amino acids to fats and carbohydrates?

Answer 18

So you can store them

Question 19

What is selective reabsorption?

Answer 19

When your body chooses what to absorb again e.g. water, glucose, ions or salts

Question 20

what substances are removed by the kidney?

Answer 20

urea, excess salts, water

Question 21

What controls urine concentration?

Answer 21

antidiuretic hormone

Question 22

where does antidiuretic hormone come from?

Answer 22

pituitary gland

Question 23

when is ADH release?

Answer 23

when the water in your blood is reduced It makes you wee less

Question 24

what happens in kidney failure?

Answer 24

build up of waste products in blood

Question 25

what is dialysis?

Answer 25

a machine that filters the blood

Question 26

how does a dialysis machine work?

Answer 26

blood flows between partially permeable membrane surrounded by dialysis fluid
waste moves out into the dialysis fluid
useful substances can’t pass out into fluid

Question 27

how many times do you need dialysis?

Answer 27

2-3 times a week

Question 28

what is the other option for kidney failure other than dialysis?

Answer 28

Kidney transplant

Question 29

types of kidney transplant?

Answer 29

dead and alive

alive is better

Question 30

risks of kidney transplant

Answer 30

body can reject it so you have to take immunosuppressants which increases risk of infection or illnesses

Question 31

advantage of transplant

Answer 31

cheaper than dialysis
more freedom
can be taken from a family member with the same blood type