Chapter 12 - Coordination and Response (not done)

Question 1

Define stimuli

Answer 1

change in the environment that can be detected by organisms

Question 2

Define receptors

Answer 2

cells or groups of cells that can detect stimuli

Question 3

Define effectors

Answer 3

parts of the body that respond to a stimulus (e.g. muscles and glands)

Question 4

Define coordination

Answer 4

the way that receptors detect stimuli and pass information to receptors

Question 5

What are the 2 methods in which animals pass on information?

Answer 5

nerves and hormones

Question 6

Define nerves

Answer 6

fastest method to transport transformation, part of the nervous system

Question 7

Define hormones

Answer 7

slower method to transport information but still important. these chemicals are part of the endocrine system

Question 8

Define neuron

Answer 8

specialised cells in the human body that conduct electrical impulses quickly

Question 9

How many types of neurons are there in the body?

Answer 9

several

Question 10

Define motor neuron

Answer 10

a type of neuron that transmits electrical impulses from the central nervous system to an effector

Question 11

Are neurons typically long or short?

Answer 11

long

Question 12

Complete the sentence:
Neurons have thin fibres of cytoplasm that…

Answer 12

stretch out from cell body

Question 13

What is the longest fibre in the body?

Answer 13

axon

Question 14

What is the shortest fibre in the body?

Answer 14

dendrites

Question 15

What is the function of dendrites?

Answer 15

to pick up electrical signals called nerve impulses from other neurons nearby

Question 16

What part of the neuron is the following sentence describing?
Some nerve fibres of active animals are wrapped in a layer of fat and protein

Answer 16

myelin sheath

Question 17

What is the function of myelin sheath?

Answer 17

to insulate the nerve fibres so they can carry signals even faster

Question 18

What 2 types of nervous systems do mammals have?

Answer 18

central nervous system (CNS) and peripheral nervous system (PNS)

Question 19

What makes up the central nervous system?

Answer 19

brain and spinal cord

Question 20

What makes up the peripheral nervous system?

Answer 20

other nerves in body

Question 21

What is the main function of CNS?

Answer 21

to coordinate the electrical impulses travelling through the nervous system

Question 22

What are the 3 characteristics of the PNS?

Answer 22

• made up of nerves that spread out from CNS
• each nerve contains hundreds of neurons
• includes receptors in our sense organs

Question 23

What is meant by the term ‘CNS’?

Answer 23

central nervous system

Question 24

What is meant by the term ‘PNS’?

Answer 24

peripheral nervous system

Question 25

Are reflexes considered reactions?

Answer 25

yes

Question 26

Define reflex arcs and explain where the pass through

Answer 26

the pathway along which an electrical impulse is passed (receptor → **sensory neurone → relay neurones → motor neuron** → effector)

Question 27

What is meant by 'reflexes are involuntary'?

Answer 27

it means that for a reflex to happen, we don't have to think about them

Question 28

Name one thing that is useful about reflexes

Answer 28

they are fast but our brains are still made aware of them.

Question 29

What happens when a hand touches a hot plate

Answer 29

nerve impulse from motor neuron makes the muscle contract

Question 30

Explain the reflex arc of a hand touching a hot plate

Answer 30

1) hand touches hot plate 2) sensory receptor in hand detects hot stimulus 3) the receptor starts of an electrical impulse 4) electrical impulse travels to the spinal chord along the axon from the receptor cell 5) this is called a sensory neuron because it's carrying an impulse from a sensory receptor 6) in the spinal, neuron passes impulse to several other neurons. these are called **relay neurons** because they pass the impulse on 7) relay neurons pass the impulse to the brain, as well as a motor neuron that will pass it on to an effector 8) impulse passes down axon of a motor neuron to arrive at effector 9) arm muscle contracts 10) hand is pulled away

Question 31

Give 3 information about the sensory neuron regarding the dendrites, the axons and nervous system

Answer 31

long dendrites, short axons, take info from our senses to CNS

Question 32

Give 3 information about the relay neuron regarding the dendrites, the axons and nervous system

Answer 32

short dendrites, no axons, only in eyes, brain and spinal cord

Question 33

Give 3 information about the motor neuron regarding the dendrites, the axons and nervous system

Answer 33

short dendrites, long axons, carry impulses away from CNS towards PNS

Question 34

Define synapse

Answer 34

a junction between 2 neurons

Question 35

What does a nerve impulse have to do to be passed from one neuron to the next?

Answer 35

it needs to cross a synaptic gap (a tiny gap between 2 neurons at a synapse)

Question 36

What is there inside the axon of a neuron?

Answer 36

hundreds of tiny **vesicles (tiny vacuole)**

Question 37

What do vesicles contain?

Answer 37

neurotransmitters

Question 38

Define neurotransmitters

Answer 38

chemical molecules that diffuse across the synaptic gap to set up an electrical impulse for the next neuron

Question 39

Explain synaptic transmission

Answer 39

1) electrical impulse travels along axon 2) causes movement of vesicles towards cell membrane 3) merge with cell membrane & release neurotransmitters (NT's) into synapse 4) NT's diffuse across gap 5) NT's attach to receptors on next neuron (complementary shape) 6) binding triggers impulse to begin in that neuron

Question 40

In how many directions does synaptic transmission happen?

Answer 40

only one

Question 41

Define sense organs

Answer 41

a group of receptor cells that can respond to a specific stimulus using 5 senses