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Flashcards in Unit 5 Deck (46)
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1

Why are homeostatic control systems important in the body?

They maintain the right conditions for cells to function

2

Which part of the nervous system do the brain and spinal cord form

CNS

3

What's the function of the nervous system in humans

It allows them to react to their surroundings and co-ordinate their behaviour

4

Name two types of effector and state how they respond to nervous impulses

Muscles can contract
Glands can secrete hormones

5

What are the three types of neurones

Sensory neurones, motor neurones, relay neurones

6

How is a signal transmitted across a synapse

Chemicals diffuse across a gap and transfer the nerve signal

7

Name the type of cell that makes up most of the brain's material

Neurones

8

State two activities that take place in the human body which are unconscious

Respiration
Heart rate

9

Why is it difficult to investigate and treat brain disorders

It is very complex and very fragile

10

Which two parts of the eye change shape during focusing

Suspensory ligaments
Cillary muscles

11

Why is it important to the pupil to change size

So that the amount of light entering can be controlled so that bright light cannot damage the retina and to allow sufficient light to enter the item condition

12

What is the process of accommodation?

Focusing light on the retina by changing the shape of the lens

13

How does the eye work to focus on a near object

The ciliary muscles contract and the suspensory ligament slacken
The lens becomes more curved
The lens refracts light rays strongly

14

How does the eye work to focus on a distant object

The ciliary muscles contract and the suspensory ligaments are pulled tight
This means that the lens becomes less curved
Therefore less light is refracted

15

Explain how a spectacle lens correct the sight of a person with a vision defect

The lens refract light rays so they focus on the retina

16

What does a concave lens look like

a sand timer

17

What is a convex lens looks like

And eye

18

How can you laser technology correct vision defects

It changes the shape of the cornea to change how strongly light is refracted into the eye

19

Suggest the risk of replacement lens surgery

The retina could become damaged

20

Explain how the thermoregulatory centre receives information about the temperature outside the body

Receptors on the skin send back nervous impulses to the thermoregulatory centre

21

Describe what happens to excess glucose in the blood

It moves into liver and muscle cells and is converted to glycogen for storage

22

What is the defining characteristic of type 1 diabetes

Uncontrolled high blood glucose level

23

Explain how glucagon increases blood glucose concentration

Glucagon causes glycogen to be converted into glucose and be released into the blood

24

Give two treatments a doctor would recommend for type 2 diabetes

A carbohydrate controlled diet and regular exercise

25

Jim is obese but doesn't have diabetes. After he drinks the sugar drink, his blood glucose level rises and then Falls. Explain why this happens.

The blood glucose concentration starts increasing as glucose from the drink is absorbed into the blood. The pancreas detects a high blood glucose concentration and secrete insulin. Insulin causes the blood glucose concentration to fall back down.

26

What process do the kidneys used to produce urine

Filtration

27

A process in the kidneys Returns useful substances to the blood so that they are not lost in urine. What is the name of this process?

Selective reabsorption

28

Name three useful substances that are returned to the Blood by selective reabsorption

Water, ions and glucose

29

Give three ways water can be lost from the body

Breathing out from the lungs, sweating and urine

30

Can the body control water loss from the skin

No