chapt. 2 + 3

Question 1

neurons

Answer 1

neuron is an individual nerve cell that is specialised to receive, process and/or transmit information.

Question 2

types of neurons

Answer 2

• sensory
• motor
• interneurons

Question 3

sensory: afferent neurons

Answer 3

transmit information from receptor in the body to the brain

Question 4

motor (efferent) neurons

Answer 4

transmits information regarding movement from the brain (CNS) to the muscles in the body

Question 5

interneurons

Answer 5

enable sensory and motor neurons to communicate and are located within the brain and spinal cord (CNS only)

Question 6

communication withing neurons

Answer 6

1. information is received by receptor sites on the dendrite
2. this may trigger an action potential
3. this electrical message travels along the axon
4. reaching the axon terminal

Question 7

communication between neurons

Answer 7

1. the neural impulse reaches the axon terminals of the presynaptic neurons
2. this causes the vesicles to release neurotransmitters into the synaptic gap
3. the neurotransmitters then bind to the complementary receptor sits on the dendrites of the post-synaptic neuron
4. the neurotransmitters then make either an excitatory or inhibitory effect on the post-synaptic likelihood of firing

Question 8

somatic NS

Answer 8

connects to our sensory receptor and skeletal muscles.
- a division of the peripheral
nervous system that
transmits neural messages
related to voluntary motor
movement

Question 9

Autonomic NS

Answer 9

the self regulation of body’s organs, visceral muscles and glands, without conscious effort

Question 10

sympathetic NS (divisions of ANS)

Answer 10

activates the internal muscles, organs and glands to prepare the body for vigorous activity or to deal with stressful or threatening situation.
- enhance survival

Question 11

examples of sympathetic NS

Answer 11

• dilates pupils
• accelerates HR
• inhibits digestion
• adrenaline released
• relaxes bladder

Question 12

parasympathetic NS (division of ANS)

Answer 12

in time of minimal stress and in the absence of threat, it helps to maintain the internal body environment in a steady, balanced state or normal functioning
- counterbalances SNS
- restores to calm

Question 13

examples of PNS

Answer 13

• contracts pupils
• slows HR
• stimulates digestion
• adrenaline no longer produced
• contracts bladder

Question 14

conscious response

Answer 14

deliberate and voluntary response. involves the conscious awareness of both internal and external stimuli
- putting on a jumper when cold

Question 15

unconscious responses

Answer 15

doesn’t involve awareness. automatic and involuntary.
- goose bump or shivering due to cold

Question 16

spinal reflex

Answer 16

unconscious, involuntary and automatically occurring response to a certain stimuli without the intervention of the brain
- enables a faster reaction time and is considered and adaptive response

Question 17

neurochemicals

Answer 17

• vital role in between-neuron (chemicial) communication and brain function
• include neurotransmitter and neuromodulators

Question 18

neurotransmitters (nerochemicals)

Answer 18

• excitatory effect
  (glutamate) they make the post-synaptic neuron more likely to fire
• inhibitory effect
  (GABA) they make the post synaptic gaps less likely to fire

Question 19

neurochemical transmission across the synapse

Answer 19

1. Key: each type of NC has a chemically distinct shape
2. Lock: the NC will search for a receptor site that has a complimentary shape
3. Binds: once the NC finds the matching receptor it then binds to it
4. Unlocks: this then unlocks the post synaptic neuron, having either a inhibitory or excitatory effect

Question 20

Neuromodulators

Answer 20

• act as a neurotransmitter, directly communicating across a synapse, influencing an individual neuron
• communicate on a wider scale in the brain, influencing multiple neural signal.
• slower acting but longer lasting
• must still bind to receptor sites

Question 21

neuromodulator - serotonin

Answer 21

• inhibitory effect
• regulation of mood and sleep
• appetite, digestion and arousal

Question 22

Dopamine

Answer 22

• excitatory or inhibitory effect on neurons as it depend on the specific neuron
• pleasure and reward based learning
• voluntary movement
• motivation and addiction

Question 23

synaptic plasticity

Answer 23

is the brain ability of synaptic connection changing over time.
- result of experiences.
- includes LTP and LTD

Question 24

Long term potentiation (LTP)

Answer 24

is the repeated co-activation of these neurons that leads to a strengthening of synaptic connections
- increase number of receptor sites
- bushier dendrites
- increased umber of synaptic connections

Question 25

long -term depression (LTP)

Answer 25

• the relatively permanent weakening of the synaptic connections as a result of repeated low-level activation
• decreasing # of receptor sites
• decreasing # of dendrites (pruning)
• decreasing # of synaptic connection (pruning)

Question 26

How does LTD & LTP modify the brian?

Answer 26

• sprouting (growth of dendrite spines, filigree appendages & synaptogenesis)
• re-ruting (new alternative pathway)
• pruning (elimination of synaptic connections)