the CNS and neurotransmitters

Question 1

what is the function of the CNS

Answer 1

collet, process, and respond to all info in the environment
coordinate the working of different organs and cells

Question 2

draw the human nervous system

Answer 2

human NS —> CNS and PNS

CNS —> brain and spinal cord

PNS —> ANS and SNS

ANS —> sympathetic and parasympathetic

Question 3

describe the brain

Answer 3

centre of all consciousness
2 hemispheres

Question 4

describe the spinal cord

Answer 4

reflex actions
passes messages to and from brain and connects nerves to and from PNS

Question 5

describe the peripheral nervous system

Answer 5

transmits messages via neurones

somatic NS - sensory and motor info to and from spinal cord

automatic NS - vital body functions
- sympathetic and parasympathetic

Question 6

describe fight or flight

Answer 6

Sympathetic - fight or flight
- slows digestion
- inhibits saliva production
- increases heart rate
- simulates glucose production
- dilates pupils

parasympathetic - rest and digest

Question 7

draw a neurone

Answer 7

cell body
dendrites
nucleus
axon
mitochondria
axon hillock
schawnn cell
node of ranvier
myekin sheath
terminal button
axon terminal

Question 8

what is the role of the neurone

Answer 8

nerve impulses that travel from dendrites to axon terminal buttons which travel across a synapse next to neurone, chemical messages only

Question 9

what are the 3 types of neurone

Answer 9

sensory - messages to CNS
motor - messages from CNS
relay - connect sensory and motor

Question 10

describe neurotransmission

Answer 10

• an action potential - electrical message being transmitted within the neuron
  synamptic transmission - chemical messages being passed between neurons

Question 11

describe the process of an action potential

Answer 11

• neurones have a resing membrane potential of -70mV inside more -ve than outside
• when a neuron recieves a message it results in either inhibition or exitation of post synaptic neuron
• exitation means it will depolarise neurone making it more +ve
• inhibition means it will hyperpolarise
• when neurone reaches threshold of -55mV action potential triggered

Question 12

decribe the process of synaptic transmission

Answer 12

• action potential reaches axon terminal
• Ca2+ flow into neuron via calcium ion channels
• caues vessicles in terminal buttons to migrate to membrane and release NTs into synapse
• Nts bind to receptors
• depending on the receptor it results in inhibition or excitation
• NTs left in synapse are deactivated by uptake or degraded by enzymes

Question 13

what is a neurotransmitter

Answer 13

chemical messengers that transmit info across a synapse from one neurone to another

Question 14

what does the NT acetylcholine do

Answer 14

stimulates muscle contractions, motor control and movement, memory, attention and alertness

Question 15

what does the NT noradrenaline do

Answer 15

emotion, sleeping, dreaming ans learning

Question 16

what does the NT dopamine do

Answer 16

emotion and cognitive function, posture and conrol of movement, reinforcement in learning, hormone regualtion

Question 17

what does the NT serotonin do

Answer 17

mood control, pain, sleep, regulating body temperature, hunger

Question 18

evaluate the CNS and NTs

Answer 18

+ McNean and cimbolic found that people with depression have a lower level of 5-HIAA formed when serotonin is broken down, low levels of serotonin in their brain, relates to mood control
+ Martinez and kesner investigated effect of acetylcholine on rats ability to rember maze, made more wrong turns, effects memory
- aminal reseatch, neurotransmission in humans more complex
- brain damage and recreational drugs can change behaviour, cant be certain NTs are the thing affecting behaviour
+ useful in developing drug treatments eg. antidepressants, function in society better