B3.3

Question 1

What temperature does the body work best at?

Answer 1

The body works best at 37 degrees Celsius as this is the optimum temperature for enzymes

Question 2

What can extreme exposure to cold do?

Answer 2

It can reduce core body temperature, which means enzyme reactions occur to slowly and cells begin to die

Question 3

At what temperature are you at risk of hypothermia?

Answer 3

If the core temperature drops below 35 degrees then you’re at risk of hypothermia

Question 4

When can exposure to high temperatures do?

Answer 4

Exposure to high temperatures can cause body to overheat, and enzymes can denature

Question 5

What part of the brain regulates body temperature?

Answer 5

The thermoregulatory centre is responsible for regulating body temperature

Question 6

When are you at risk of hyperthermia?

Answer 6

At temperatures above 40-42 degrees

Question 7

What does the thermoregulatory centre in the brain rely on?

Answer 7

It relies on signals from receptor cells in your skin and internal receptor cells

Question 8

What happens when a change in temperature is detected?

Answer 8

The brain causes different parts of the body to respond by sending impulses to effectors, which restore the body to its normal temperature

Question 9

What happens when you get too hot?

Answer 9

Changes like:
Body hairs lie flat
Sweating
Vasodilation

Explain

Question 10

What happens when you get too cold?

Answer 10

Changes:
Shivering
Body hairs rise
No sweating
Vasoconstriction

Explain

Question 11

What is glucose?

Answer 11

Glucose is an energy store where chemical reactions transfer energy from glucose to ATP which is used by cells

Question 12

What happens after you eat?

Answer 12

The glucose released by digestion passes into the bloodstream causing blood sugar levels to rise.

Question 13

What happens if high blood glucose is maintained?

Answer 13

Body systems can be damaged, especially nerves and blood vessels

Question 14

What happens when you exercise?

Answer 14

More glucose is needed to transfer more energy which causes blood sugar levels to drop. This can prevent cells from respiring effectively

Question 15

What hormone controls high blood sugar levels?

Answer 15

Insulin, which is secreted by the Pancreas and travels through the blood to the liver where it stimulates the conversion of glucose into glycogen, a store of glucose

Question 16

What hormone controls low blood sugar levels?

Answer 16

Glucagon, which is secreted by the Pancreas and travels through the blood to the liver where it stimulates the conversion of glycogen into glucose

Question 17

What is diabetes?

Answer 17

Diabetes is when blood sugar levels remain high. It is not curable but can be controlled successfully

Question 18

What is type 1 diabetes?

Answer 18

Type 1 diabetes is when the person’s own immune system destroys the pancreatic cells that make insulin - normally occurs in childhood

Question 19

What is type 2 diabetes?

Answer 19

Type 2 diabetes is when the person’s cells don’t produce enough insulin or the person’s body cells don’t respond to insulin

Question 20

When does type 1 diabetes usually occur?

Answer 20

Type 1 diabetes usually occurs in childhood

Question 21

When does type 2 diabetes usually occur?

Answer 21

Type 2 usually occurs in adulthood and is linked to obesity

Question 22

How do you control a type 1 diabetic?

Answer 22

Regular injections of insulin, a balanced diet and regular exercise

Question 23

How do you control a type 2 diabetic?

Answer 23

Regulate a person’s carbohydrates intake through their diet and match this to their exercise levels

Overweight people are encouraged to lose weight

Insulin-stimulating drugs

Question 24

Draw a diagram of the unitary system

Answer 24

See pg. 120

Question 25

How much water does the body need?

Answer 25

The body needs around 2 litres of water every day, but in some circumstances you may need to lose more e.g when you sweat as water and salts are lost from the body

Question 26

How does the body respond to a lack of water?

Answer 26

It triggers a thirst response which tells the body to take on more fluids
->
Dehydration is the condition where you’ve not taken enough water in your body

Question 27

How does the body respond to too much water?

Answer 27

Body produces lots of urine, but if there is TOO much water then cells burst. This drops levels of sodium in blood plasma, leading to muscle cramps, seizures and fainting. If it reaches brain cells and these burst you can die

Question 28

What are hypotonic drinks?

Answer 28

Drinks containing low concentrations of glucose and salts

Question 29

What are hypertonic drinks?

Answer 29

Drinks that contain high concentrations of glucose and salts

Question 30

What are isotonic drinks

Answer 30

Drinks that contain equal amounts of ions with those in the blood plasma.

Question 31

What are the views on sports drinks?

Answer 31

Some people believe that sports drinks can improve the performance of an athlete, but not all scientific claims for this are true