14. Co-ordination and Response

Question 1

Define

Synapse

Answer 1

The junction between two neurones

Question 2

Define

Hormone

Answer 2

A chemical substance,
produced by a gland and carried by the blood,
which alters the activity of one or more specific
target organs

Question 3

Where is glucagon secreted?

Answer 3

Pancreas

Question 4

Where is adrenaline secreted?

Answer 4

Adrenal glands

Question 5

Where is insuline secreted?

Answer 5

Pancreas

Question 6

Where is testosterone secreted?

Answer 6

Testes

Question 7

Where is Oestrogen secreted?

Answer 7

Ovaries

Question 8

Define

Adrenaline

and its effects

Answer 8

the hormone secreted in
‘fight or flight’ situations and its effects,
(a) increased breathing rate
(b) increased heart rate
(c) increased pupil diameter

Question 9

How does adrenaline affect metabolic activity?

Answer 9

a) increasing the blood glucose concentration
(b) increasing heart rate

Question 10

Define

Homeostasis

Answer 10

The maintenance of a
constant internal environment

Question 11

What function does Insulin serve?

Answer 11

It decreases blood glucose
concentration

Question 12

Define

Vasodialation

Answer 12

Sphincter muscle relaxes to allow more blood to go to the surface capillaries for heat loss

Question 13

Define

Vasoconstriction

Answer 13

Sphincter muscle contract to allow less blood to go to the surface capillaries for heat loss

Question 14

3 marks

What does the skin do to regulate body temperature in a cold environment?

Answer 14

• Vasoconstriction
• Less sweat secreted from the sweat glands
• Hair erector muscles contract so hair rises

Question 15

4 marks

What does the skin do to regulate body temperature in a hot environment?

Answer 15

• Vasodialation
• More sweat secreted from the sweat glands
• Hair erector muscles relax so the hair lays flat
• Muscles cause shivering (involuntary contractions)

Question 16

Name the three layers of skin

Answer 16

Epidermis
Dermis
Adipose tissue

Question 17

5 marks

Examples of Homeostasis?

Answer 17

• Body temperature
• Water potential
• Blood pH
• Oxygen/Carbon dioxide concentration
• Glucose concentration level in blood

Question 18

Importance of Homeostasis?

Answer 18

• Optimum temperature for enzymes
• So that cells do not gain too much water by osmosis and burst

Question 19

Treatment for Type 1 Diabetes

Answer 19

1. Regular monitoring of blood glucose level
2. Injecting Insulin
3. Diet - reduced intake of sugars (eat slow release carbs eg starch)
4. Exercise - regular aerobic exercise

Question 20

What does the CNS constist of ?

Central Nervous System

Answer 20

Brain and the Spinal cord

Question 21

What does the PNS consist of?

peripheral nervous system

Answer 21

Nerves outside of the brain
and spinal cord

Question 22

Define

Reflex action

Answer 22

A means of
automatically and rapidly integrating and
coordinating stimuli with the responses of
effectors (muscles and glands)

Question 23

Define

Effectors

Answer 23

Muscles or glands that bring about a response

Question 24

What carries our coordination and response?

Answer 24

The Nervous System
The Endocrine System

Question 25

Why is coordination and response needed?

Answer 25

1. To respond to stimuli in your environment 2. To maintain a constant internal environment (homeostasis)

Question 26

Name the types of neurones and their connections

Answer 26

1. Sensory neurone - from the sense organ to the CNS 2. Relay neurone - Sensory nerve to the motor neurone 3. Motor neurone (in the CNS) - Relay neurone/CNS to the effector

Question 27

Describe how an impulse travels | reacting to the stimuli of heat or a pin

Answer 27

Stimulus is detected by the receptor (skin), sensory neurone send impulses to the spinal cord (the coordinator), impulse travels through the relay neurone to the motor neurone, to the effector (muscle), effector carries out a response (musle contracts to pull arm up)

Question 28

Describe reflex actions

Answer 28

Automatic Rapid response Protective - minimise damage to the body

Question 29

What is the function of the synapse?

Answer 29

To ensure that an impulse travels in one direction only

Question 30

# 6 marks Explain how an impulse moves across the synapse

Answer 30

1. An electrical impulse arrives through the presynaptic neurone 2. This intiates the vesicles containing neurotansmitters to fuse with the membrane and and release neurotransmitters into the synapse 3. Neurotransmitter diffuse across the synapse/synaptic gap 4. Neurotransmitter bind to the protein receptors, on the post synaptic nerve, with specific complementary shapes to theirs. 5. This intiates a nerve impulse in the post synaptic nerve. | neurotransmitters are destroyed after to prevent continued stimulation o

Question 31

Sense organs and what they sense

Answer 31

* Eyes - Light * Skin - Temperature, Pain, Pressure, Touch * Nose - Chemicals in the air * Tongue - Chemicals in food and drinks * Ear - Sounds and Acceleration

Question 32

# Define Sense organ

Answer 32

Groups of receptor cells responding to specific stimuli

Question 33

What is the function of the cornea?

Answer 33

Refracts light

Question 34

What is the function of the Iris

Answer 34

Controls how much light enters the pupil

Question 35

What is the function of the Lens?

Answer 35

Focuses light on to the retina

Question 36

What is the function of the Retina?

Answer 36

Contains light receptors, some sensitive to light of different colours | rods and cones

Question 37

What is the function of the optic nerve?

Answer 37

Carries impulses to the brain

Question 38

How does the iris control the size of the pupils?

Answer 38

The circular and radial muscles work antagonistically. When in bright light, circular muscles contact When in a dim environment, radial muscles contract | This is to protect the retina