Homeostasis

Question 1

What is homeostasis? an example

Answer 1

• The body’s ability to maintain a constant internal environment.
• to ensure the survival of the organism

eg. regulation of body temp, water balance, blood glucose levels

Question 2

What are some conditions in the body that need to be kept constant?

Answer 2

regulation of body temp - body temperature at 37°C
, water balance, blood glucose levels

Question 3

How does the body maintain homeostasis

Answer 3

by the stimulus-response model
Stimulus—> Recepters–> contral–> effecter—> response

Question 4

Explain the role of the stimulus-response model.
Then using

Answer 4

allow your body to respond to external or internal stimuli to maintain homeostasis

Question 5

What is a negative feedback loop. and example

Answer 5

Aims to reverse the effects of a stimulus

The most common form of feedback
E.g. Shivering when cold to reverse the effects of a drop in temperature

Question 6

What is a positive feedback loop?

Answer 6

Aim to increase the effects of a stimulus

Only 4 examples of humans
E.g.
1. Childbirth
2. Lactation (milk production)
3. Ovulation
4. Blood Clotting

Question 7

explain how blood glucose levels are regulated.

Answer 7

Insulin and glucagon help maintain blood sugar levels
how it works

1. TOO MUCH glucose in blood
2. Pancreas produces insulin which enters blood
3. Insulin allows glucose to be absorbed by body cells
4. Blood glucose REDUCED

Question 8

What happens in diabetes

Answer 8

steps
1. Stomach converts food to glucose
2. Glucose enters bloodstream
3. The pancreas produces insulin, but it is resistant to effective use.
4. Glucose is unable to enter the body effectively
5. Glucose levels increase

• your body doesn’t make enough insulin
• can’t use it as well as it should. When there isn’t enough insulin or cells stop responding to insulin,
• too much blood sugar stays in your bloodstream

Question 9

stimulus meaning

Answer 9

A change which occurs in either the internal or external environment

Question 10

receptor

Answer 10

Detects the stimulus and sends a message to the control center

Triggers body’s reaction (e.g., touching hot stove).

Question 11

control centre

Answer 11

Interprets the message and send out a responding message to effector

Question 12

effector

Answer 12

are usually muscles and glands that respond appropriately to the stimulus

Question 13

Set point

Answer 13

This setpoint is what homeostasis tries to achieve.