control and coordination

Question 1

3 types of neurones

Answer 1

1. sensory neurones
2. motor neurones
3. intermediate neurones

Question 2

each neurone has:

Answer 2

1. axon
2. dendrites
3. synapse

Question 3

axon

Answer 3

sends messages to other neurones/ body parts

Question 4

dendrites

Answer 4

receive messages from other neurones

Question 5

synapse

Answer 5

tiny gap between neuron
es where impulses are transmitted via neurotransmitter molecules

Question 6

sensory neurone features

Answer 6

• long dendron: brings impulses towards cell body
• single axon
• transmit impulses from receptors to spinal cord/brain

Question 7

motor neurone features

Answer 7

• cell body lies between brain/spinal cord
• single long axon
• many dendrites
• transmit impulses from cns to effector organs (e.g. mucles/glands)

Question 8

intermediate neurone features

Answer 8

• numerous short fibres
• occurs in cns
• connect sensory to motor neurones

Question 9

chemoreceptors

Answer 9

specialised sensory receptors in our sense organs which recognise the chemical stimuli by which organisms collect information about their internal and external environments
- present in sense of taste and smell

Question 10

junctions between 2 neurons

Answer 10

synapse

Question 11

2 types of synapses

Answer 11

1. electrical
2. chemical

Question 12

electrical synapse

Answer 12

contain gap junctions —> allow electrical current to flow directly from 1 neuron to another

Question 13

chemical synapse

Answer 13

rely on the release of chemical neurotransmitter by presynaptic neurone to transfer info to the target cell using synaptic vesicles

Question 14

primary neurotransmitter involved in neuromuscular functions

Answer 14

acetylcholine

Question 15

features of synapses

Answer 15

• able to filter out low level stimuli
• protect effectors from over stimulation and synapse fatigue
• flexibility of response for CNS
• allow integration of information from different types of neurones

Question 16

synapse fatigue

Answer 16

temporary reduction in a neuron’s ability to transmit a signal due to high-frequency stimulation

Question 17

max frequency of impulses

Answer 17

500-1000 per second

Question 18

“all or nothing” principle

Answer 18

stimulus must be at or above threshold of stimulation to initiate action potential

Question 19

function of myelin sheath and node of ranvier

Answer 19

help increase the speed at which impulses are conducted

Question 20

Why does an action potential travel faster in a myelinated neurone compared to a non-myelinated neurone?

Answer 20

• myelin sheath made up of schwann cells which don’t conduct electricity + node of ranvier which conducts electricity
• an action potential jumps by saltatory conduction
• travels faster

Question 21

protein filaments in the muscles

Answer 21

main:
1. actin (thin)
2. myosin (thick)
additional:
1. titin
2. nebulin

Question 22

titin

Answer 22

• act as a “spring” to keep the myosin centered in the
  sarcomere
• maintains resting tension of the muscle

Question 23

nebulin

Answer 23

• extend from the Z disc
• regulates the assembly and
  length of the actin

Question 24

parts of neurone that become depolarised

Answer 24

• axon
• dendrites
• nodes of ranvier

Question 25

parts of neurone that contains many mitochondria

Answer 25

- cell body - dendrites

Question 26

parts of neurone that acts as an insulator

Answer 26

- myelin sheath

Question 27

saltatory conduction

Answer 27

rapid transmission of a nerve impulse from one node of ranvier to another