Nervous System

Question 1

stimulus

Answer 1

any change in your environment

Question 2

receptor

Answer 2

a cell that can detect a stimulus

Question 3

Neuron

Answer 3

cells that carry electrical signals & are involved in fast responses

Question 4

Impulse

Answer 4

an electrical message that is carried along a neuron

Question 5

Co ordinating a response

Answer 5

1. Reception
2. Transmission to CNS
3. Integration; sorting and processing of message, response determined
4. Transmission to PNS
5. Response; effectors (muscles or glands) stimulated to carry out an action

Question 6

CNS

Answer 6

Central nervous system; brain and spinal cord

Question 7

PNS

Answer 7

Peripheral Nervous system; network of nerves

Question 8

sensory neurons

Answer 8

sense organs to CNS

Question 9

Interneurons

Answer 9

between motor and sensory in CNS

Question 10

Motor neurons

Answer 10

between CNS and effectors

Question 11

Cell body

Answer 11

produces neurotransmitter chemicals

Question 12

Dendrites

Answer 12

receive and carry impulses towards cell body

Question 13

Axon

Answer 13

conducts impulses away from the cell body

Question 14

schwann cells

Answer 14

surround axon and make myelin sheath

Question 15

NOdes of ranvier

Answer 15

between schwann cells: speed up transfer of impulses

Question 16

myelin sheath

Answer 16

insulates nueron, preventing impulse from flowing inother neurons

Question 17

synapse

Answer 17

region where two nuerons come into close contact

Question 18

synaptic cleft

Answer 18

gap between two nuerons

Question 19

neuro transmitter swellings

Answer 19

releases chemicals that carry the impulse from one nerve to another- chemicals are neurotransmitters

Question 20

nerve fibres

Answer 20

many axons or dendrites

Question 21

threshold

Answer 21

the minimum stimulus needed to cause an impulse to be carried

Question 22

refractory period

Answer 22

short time after nueron has carried an impulse during which a stimulus fails to cause a response

Question 23

synapse

Answer 23

region where two neurons come into close contact

Question 24

synaptic cleft

Answer 24

tiny gap between two nuerons at a synapse

Question 25

Neurotransmitter

Answer 25

a chemical released across a synaptic cleft to carry a signal from one nueron to another- stored in vesicles

Question 26

functions of synapses

Answer 26

transmit impulses control impulse directions prevent overstimulation of effectors impulse can be blocked by certain chemicals

Question 27

meninges

Answer 27

triple layered membrane

Question 28

cerebrospinal fluid

Answer 28

acts as a shock absorber

Question 29

grey matter

Answer 29

cell bodies and synapses

Question 30

white matter

Answer 30

dendrites and axons with myelin sheaths

Question 31

cerebrum

Answer 31

voluntary movement, intelligence, language

Question 32

cerebellum

Answer 32

balance, co ordination

Question 33

medulla oblongata

Answer 33

connects brain to the spinal cord and controls involuntary movement

Question 34

thalamus

Answer 34

sorting centre; relays messages to the brain

Question 35

pituitary gland

Answer 35

secretes hormones and controls endocrine glands

Question 36

hypothalamus

Answer 36

controls osmoregulation, body temperature and sleep

Question 37

Parkinsons disease

Answer 37

loss of motor fuction; missing NT dopamine causes tremors, stiff joints, slow walk

Question 38

dorsal root

Answer 38

carries sensory neurons into spinal cord

Question 39

dorsal root gangalion

Answer 39

swelling that consists of cell bodies of sensory neurons

Question 40

ventral root

Answer 40

carries motor neurons away from spinal cord

Question 41

central root

Answer 41

containd cerebrospinal fluid

Question 42

reflex action

Answer 42

quick, automatic response to a particular stimulus; straight from sensory neuron to spinal cord to effector; subconscious action