Homeostasis

Question 1

Homeostasis involves…..

Answer 1

Control systems that keep your internal environment roughly constant (within certain limits)

Question 2

Why is it important to maintain the right core body temperature and blood pH?

Answer 2

Because temperature and pH affect enzyme activity, and enzymes control the rate of metabolic reactions

Question 3

If body temp is too high…..(above 40•c)…..

Answer 3

Enzymes become denatured. The enzyme molecules vibrate too much which breaks the hydrogen bonds that hold their tertiary structure in shape.

Question 4

If the shape if and enzymes active site is changed…, what happens?

Answer 4

The enzyme no longer works as a catalyst this means metabolic reactions are less efficient,

Question 5

If body temp is too low……

Answer 5

Enzyme activity is reduced, slowing the rate of metabolic reactions.

Question 6

Highest rate of enzyme activity happens at what temp?

Answer 6

37•c (in humans)

Question 7

If blood pH is too high or too low….

Answer 7

Enzymes become denatured. The hydrogen bonds that hold them together in their tertiary structure are affected so the shape of the enzyme active site is changed and it no longer works as a catalyst.

Question 8

If an enzyme can no longer work as a catalyst, to the body this means….

Answer 8

Metabolic reactions are less efficient!!

Question 9

Why is it important to maintain the right concentration of glucose in the blood??

Answer 9

Because cells need glucose for energy!

Question 10

If blood glucose concentrations are too high what does this do to the water potential of the blood??

Answer 10

The water potential of the blood is reduced to a point where water molecules diffuse out of cells into the blood by osmosis. This can cause the cell the shrivel up and die.

Question 11

What happens when blood glucose concentrations are too low??

Answer 11

Cells are unable to carry out normal activities because there isn’t enough glucose for respiration to provide energy!

Question 12

Homeostatic systems involve…..

Answer 12

Receptors, communication systems, and effectors.

Question 13

What is homeostasis

Answer 13

Homeostasis is the maintenance of a constant body temperature

Question 14

What is menstration?

Answer 14

When there is no fertilisation, the uterus lining breaks down and leaves the body via the vagina. Marks start and end if each cycle.

Question 15

4 hormones of the menstrual cycle??

Answer 15

Follicle-stimulating hormone
Luteinising hormone
Oestrogen
Progesterone

Question 16

What does FSH do??

Answer 16

It stimulates the follicle to develop

Question 17

Luteinising hormone - what does it do?

Answer 17

Stimulates ovulation and stimulated the corpus Luteum to develop

Question 18

What does oestrogen do?

Answer 18

Stimulates the uterus lining to thicken

Question 19

What does progesterone do?

Answer 19

Maintains the thick uterus lining, ready for implantation of an embryo

Question 20

Ovaries secrete…?

Answer 20

Oestrogen & progesterone

Question 21

The anterior pituitary gland secretes…?

Answer 21

FSH & LH

Question 22

What are endocrine glands??

Answer 22

They secrete hormones into blood, hormones travel to a target cell (with a complementary receptor) in a different part of a body e.g. Adrenaline, glucagon, insulin.

Question 23

Define a hormone?

Answer 23

Protein that is secreted in to the blood- binds to cells with complementary receptors - can have a widespread effect and spread by diffusion

Question 24

What is an exocrine gland??

Answer 24

Secrete product via duct onto surface next to gland e.g. Swear, saliva glands. It is stimulated by hormone secretion e.g. Pancreatic secretions in small intestines!!

Question 25

What 2 hormones are involved with the blood glucose regulation??

Answer 25

Insulin &

Glucagon

Question 26

Other than muscle tissue name one other type of tissue that acts as an effector?

Answer 26

Muscle tissue

Question 27

Effectors are always……

Answer 27

A muscle or gland

Question 28

How should a control group be treated??

Answer 28

Treated exactly the same as the experiment group

BUT given a placebo

Question 29

Describe the role of hormones in the fluctuation of glucose concentration between 9:00 and 12:00??

9: 00 - 70
10: 00 - 85
11: 00 - 110
12: 00 - 80

Answer 29

9-11 glucagon secreted 
✨
Glucagon stimulates breakdown of glycogen to glucose 
✨
11:00 - 12:00 insulin secreted 
✨
Insulin stimulates uptake of glucose by cells/ conversion to glycogen 
✨
Explanation of negative feedback

Question 30

FSH ….
Where is it made?
Function??

Answer 30

Pituitary gland
✨✨
Stimulates oestrogen production by follicles. Stimulates one egg to develop and become a mature follicle
💕💕💕

Question 31

Oestrogen….
Made?
Function?

Answer 31

Ovaries - follicles
✨✨✨
Stimulates LH
Stimulates rebuilding of the uterus wall.

Question 32

LH…
Made?
Function?

Answer 32

Pituitary gland
✨✨✨
Stimulates the release of an egg & stimulate progesterone production!

Question 33

Progesterone
Made??
Function??

Answer 33

Corpus Leutium (ovaries)
✨✨✨
This stimulates the growth and protection of the lining of the uterus...
Promotes glycogen storage...
Inhibits FSH