HOMEOSTASIS

Question 1

What is homeostasis?

Answer 1

Maintenance of a constant internal environment and is the control of internal conditions within set limits achieved by negative feedback

Question 2

Give examples of internal conditions

Answer 2

Temperature
blood pressure
water concentration
glucose concentration

Question 3

When does negative feedback happen?

Answer 3

When conditions change from the ideal point and returns conditions to this set point

Question 4

What are negative feedback mechanisms usually?

Answer 4

A continuous cycle of bringing levels down and then bringing them back up so that overall they stay withing a narrow range of what is considered normal

Question 5

What is the ideal body temperature for enzymes?

Answer 5

37 C

Question 6

What is hyperthermia?

Answer 6

When heat gain exceeds heat loss and the temperature rises

Question 7

What is hypothermia?

Answer 7

When heat loss exceeds heat gain and the temperature falls.

Question 8

Where is regulation controlled?

Answer 8

In the hypothalamus which contains receptors sensitive to the temperature of the blood.

Question 9

Where are there temperature receptors?

Answer 9

The skin and sends impulses via sensory neurones

Question 10

What is the top layer of the skin called?

Answer 10

Epidermis

Question 11

What is the lower layer of the skin called?

Answer 11

Dermis

Question 12

What is the dermis made of?

Answer 12

Connective tissue

Question 13

What does the connective tissue contain?

Answer 13

Elastic fibres and collagen fibres

Question 14

What happens as a person gets older?

Answer 14

Fibers lose their elasticity so the skin becomes loose and wrinkled

Question 15

What does the dermis contain?

Answer 15

Sweat glands

Question 16

What do the sweat glands do?

Answer 16

They secrete a liquid called sweat which is mostly water with small amounts of salts and urea dissolved in it

Question 17

How does sweat travel?

Answer 17

It travels up the sweat ducts and onto the surface of the skin through the sweat pores

Question 18

What happens when it is too warm?

Answer 18

Hair erector muscle relaxes lowering the hair
a thin insulating layer of air is trapped above the skin
more heat is lost to the environment by evaporation convection and radiation

Question 19

What happens when it is too cold?

Answer 19

The hair erector muscle contracts raising the hair
the hairs trap a thicker layer of air above the skin
The air insulates the skin

Question 20

What is underneath the dermis?

Answer 20

A layer of fat called adipose tissue

Question 21

What does the adipose tissue do?

Answer 21

Helps insulate the body against heat loss and acts as an energy reserve

Question 22

What is shivering?

Answer 22

When muscles in some parts of the body contract and relax very quickly

Question 23

How does shivering help?

Answer 23

Heat is generated in the muscles and warms the blood as it flows through them

Question 24

What does the dermis contain?

Answer 24

Blood vessels and nerve endings

Question 25

What do the nerve endings do?

Answer 25

They are sensitive to touch, pain, pressure and temperature

Question 26

What happens to our arterioles when we are cold?

Answer 26

They become narrower

Question 27

What is it called when our arterioles contract?

Answer 27

Vasoconstriction

Question 28

How does Vasoconstriction help?

Answer 28

Reduces the amount of heat loss from blood by radiation as less blood flows through the surface of the skin

Question 29

What happens when our arterioles when we are hot?

Answer 29

They dilate

Question 30

What is it called when our arterioles dilate?

Answer 30

Vasodilation

Question 31

How does Vasodilation help?

Answer 31

there is more blood and bc there is a lot of blood near the surface of the skin heat is readily lost from the blood into the air by radiation.

Question 32

What is an effector?

Answer 32

An effector is a part of the body that creates a response such as muscles

Question 33

What happens when the body temperature raises?

Answer 33

Temperature receptors in the skin detect an increase Nervous impulse sent to the hypothalamus and it coordinates a response sweat is released and blood vessels dilate

Question 34

What is produced when blood glucose rises?

Answer 34

Insulin

Question 35

What happens when blood glucose rises?

Answer 35

Insulin produced stimulates the liver muscle cells to convert excess glucose into glycogen

Question 36

How are blood glucose levels controlled?

Answer 36

Negative feedback mechanism involving glucagon and insulin

Question 37

Where are insulin and glucagon produced?

Answer 37

Pancreas

Question 38

Why do cells need glucose?

Answer 38

To respire to release energy

Question 39

Why is too much glucose not good for cells?

Answer 39

water moves out of the cells and into the blood by osmosis

Question 40

What is type 1 diabetes?

Answer 40

A condition where the blood glucose levels are not able to be regulated as the insulin secreting cells in the pancreas are not able to produce insulin

Question 41

What happens if you have Type 1 diabetes?

Answer 41

the blood glucose levels are too high

Question 42

How can you treat type 1 diabetes?

Answer 42

Injecting insulin

Question 43

What can having high or low blood glucose concentrations cause?

Answer 43

Damage to numerous body organs

Question 44

What is hyperglycaemia?

Answer 44

When the blood glucose concentration goes up and stays up

Question 45

What is hypoglycaemia?

Answer 45

When the blood glucose drops very low

Question 46

What can hypoglycaemia cause a person to feel?

Answer 46

very tires confusion irrational behaviour

Question 47

How can people monitor type 1 diabetes?

Answer 47

Levels of physical activity | their diet affects the amount of insulin needed