biopsycvhology - structure and functions of a neuron

Question 1

how msny neurons are there in the human nervous system

Answer 1

100 billion

Question 2

there are a 100 billion neurons in the nervous system 80% which are located in teh

Answer 2

brain

Question 3

neurons transmit signals

Answer 3

elcetrically and chemically

Question 4

by transmitting signals electrically and chemically what do these neurons privide the nervous system qith

Answer 4

its primary measn of communciatino

Question 5

what are te 3 types of neurons

Answer 5

sensory

relay

motor

Question 6

what are sensory neurons 3 points

Answer 6

carry messages form the PNS to the cns

they have long dendrites

short axons

Question 7

what is the relay neruon 3 points

Answer 7

connect sensory neuroins to the motor or other relay neurons

they have short dendrites

short axons

Question 8

what are motor neurosn

Answer 8

connect the CNS to teh effectors such as muscles and glands

short dendrites

long axons

Question 9

what are the 5 bits of a neuron we need to be able to label

Answer 9

dendrites

cell body (nucleus bit)

myelin sheath

nodes of ranvier

axon

Question 10

neurons vary in sixze from

Answer 10

less than a mm to up to a metre long

Question 11

what does cell body /soma include

Answer 11

nucleus - whihc contains genetic material of the cell

Question 12

what are dendrties

Answer 12

branchlike structures that protrude from teh cell body

Question 13

what do dendrties carry

Answer 13

nerve impulses from neighbouring neurosn towards teh cellbody

Question 14

what does the axon do

Answer 14

carries impulses away from cell body downt he length of the neuron

Question 15

what is a mylen sheath

Answer 15

covers axon in a fattu layer called the myelin sheath

it protects the axon

speeds up electrical transmission of the impulse

Question 16

if mylen sheath was continuous what effcet would it have

Answer 16

reverse eeffect and slow down the electrical impulse

Question 17

cause mylen sheath is not ocntinu=ous what is it segmentted by

Answer 17

gaps called nodes of ranvier

Question 18

what do nodes of ranvier do

Answer 18

speed up the transmision of the impulse by foricng it to jump across the gaps along the axon

Question 19

at the end of the axon what is present

Answer 19

terminal buttons

Question 20

what do terminal buttons do

Answer 20

communicate with the next neuron in the synapse

Question 21

where may the cell bodies of motor neurosn be

Answer 21

in the CNS

but they have long axons which form part of the PNS

Question 22

Where are senesory neurons located

Answer 22

outside of the cns , in the pns in clusters known as ganglia

Question 23

what do relay neurosn make up

and where are most of them found

Answer 23

97% of all neurons

most are found within the brian and the visual system

Question 24

when a neuron is in a resting state describe hte inside of a cell

Answer 24

negativley charged compared to the outside

Question 25

when a neuron is activated by a stimulus what happens and what does this create

Answer 25

inside of teh cell becomes +vley charged for a split second causing action potential to occur

this create san electrical impulse that travels down the axon towards the end of the neuron