chapter 3

Question 1

neuron comprised of

Answer 1

axon
dendrites
soma
myelin sheath
axon terminals

Question 2

dendrites

Answer 2

receive information from other neurons

- carry from synapse to soma

Question 3

soma

Answer 3

cell body which controls metabolism and maintenance of neuron
- receives messages from other neurons

Question 4

axon

Answer 4

nerve fibre that extends from soma and carries information towards the cells the communicate with that neuron

Question 5

myelin sheath

Answer 5

• coating of cells that facilitate the transmission of information to other neurons
• are white rather than grey
• protects axon from potential chemical or physical interference to electrical impulse
• insulation enables faster transmission

Question 6

axon terminals

Answer 6

found at the end of axon branch and transmit messages to the next neuron

• they have terminal buttons which have sacs that secrete neurotransmitters when an electric impulse is sent
• without touching, impulse can travel to a dendrite

Question 7

neurotransmitters

Answer 7

chemicals that transmit information from one neuron to the next via synapse
- are contained in synaptic vesicles within the terminal button of the neuron’s axon terminal

Question 8

synaptic transmission

Answer 8

process of neurons transmitting information between each other

Question 9

lock and key process

Answer 9

when a pre-synapatic neuron fires, synaptic vesicles move towards the pre-synaptic membrane, fuses with it and releases the neurotransmitters into the synaptic cleft.

• some will bind to proteins molecules (‘receptors’) located in the dendrites of the post-synaptic neuron.
• act like locks that can only be opened with one particular key or neurotransmitter; due to it having an appropriate molecular structure and electric charges
• post synaptic neuron is either inhibited or activated

Question 10

excitory

Answer 10

releases a neurotransmitter that ‘excites’ the post synaptic neuron or causes it to reach its action potential

Question 11

inhibitory

Answer 11

firing rate of post-synaptic neuron is reduced

Question 12

firing speed is dependent on

Answer 12

synaptic activity

how active soma is

Question 13

glutamate

Answer 13

excites every neuron in brain and rest of nrvous system

- important role in learning and memory

Question 14

GABA

Answer 14

inhibitory effect

- important role in regulating anxiety

Question 15

dementia

Answer 15

decrease in concentration of acetylcholine in cns

- severe memory loss and disorientation

Question 16

parkinson’s disease

Answer 16

progressive neurological condition caused by degeneration of dopamine-releasing neurons in substantia nigra

Question 17

substantia nigra

Answer 17

part of basal ganglia

(midbrain)
- responsible for reward, addiction and Parkinson’s disease (coordination of movement)
- where there are dopamine-releasing neurons

Question 18

dopamine

Answer 18

neurotransmitter that helps control the brain;s rewards and pleasure centres (including basal ganglia)

• controls messages as they pass between neurons in the substantia nigra and striatum (responsible for balance and control of movement)
• decrease in dopamine influences acetylcholine (movement)

Question 19

absence of dopamine

Answer 19

neurons in striatum fire uncontrollably and Parkinson’s sufferer unable to control their movement adequately

Question 20

symptoms

Answer 20

slowness of movement, reduced facial expressions, difficulty sleeping

Question 21

for effective motor functioning

Answer 21

striatum must have balance of dopamine and acetylcholine levels

Question 22

treatment

Answer 22

drugs

• precursors of dopamine – converted to dopamine to increase levels
• blocks action of other chemicals that affect dopamine