wk2

Question 0

Motor neuron

Answer 0

Efferent neurone
Relays messages from the brain or spinal cord to the muscles and organs
Short dendrites and long axons

Question 1

Neurones have three functions

Answer 1

Reception
Conduction
Transmission

Question 2

Sensory neuron

Answer 2

Afferent neurone
Relays messages from receptors to the brain or spinal cord
Long dendrites and short axon
Cell body and dendrite are outside of the spinal cord; the cell body is located in a dorsal root ganglion

Question 3

Interneuron ( relay)

Answer 3

Relays message from sensory neurone to motor neurone
Make up the brain and spinal cord
Short dendrites and short or long axon
Entirely within the spinal cord or CNS
Interconnect the sensory neurone with appropriate motor neuron

Question 4

Structural features

Answer 4

Cell body (soma)
Cell membrane 
Dendrite
Axon hillock 
Axon. Myelin   Nodes of ranvier 
Button 

Synapse

Question 5

Inside the neuron soma

Answer 5

Endoplasmic reticulum内质网
Cytoplasm细胞质
Ribosome核糖体
Golgi complex 
Mitochondria 线粒体
Microtubules 
Nucleus

Question 6

Synaptic buttons

Answer 6

Synaptic vesicles

Neuro-transmitters

Question 7

Resting membrane potential

Answer 7

Four keys: Na+ K+ CI- protein-

Five factors 
Random motion
Different permeability of the membrane 
Electrostatic pressure
Concentration gradients 
Sodium-potassium pump

Question 8

Saltatory conduction

Answer 8

Passive conduction alone each myelin segment to next node of ranvier

New action potential generated at each node

Instant conduction alone myelin segments results in faster conduction than in unmyelinated axons

Question 9

Glial cells : PNS

Answer 9

Schwann cells - similar to function of oligodendrocytes but in PNS, can guide atonal regeneration

Question 10

Myelin and multiple sclerosis

Answer 10

Visual blurred and double vision 
Motor weakness of muscles
Sensory numbness 
Coordination and balance 
Cognitive short and long term memory

Question 11

Glial cells : CNS

Answer 11

Oligodendrocytes - extensions rich in myelin create myelin sheaths in CNS

Question 12

Glial cells : CNS

Answer 12

Astrocytes ( star- cell)
Provide structural support
Clean up debris - phagocytosis

Question 13

The synapse

Answer 13

Three parts 
   Presynaptic terminal 
        With vesicles containing neurotransmitters 
        Receptors for reuptake
   Junction  gap
        Where the NTs 'float' briefly after release 
   Post-synaptic terminal 
        With receptors for the NTs

Question 14

3 types of directed synapses

Answer 14

Axoaxonic synapse
Increase the effects of one neuron on another ( presynaptic facilitation) others decrease the effects of one neuron in another ( presynaptic inhibition) The advantage is they selectively influence single synapses rather than the entire neuron

Question 15

Non- directed string of beads synapse

Answer 15

Neurotransmitters just release into fluid

Free to find the receptors

Question 16

When neurontransmitters are released

Answer 16

They could be
Taken up by presynaptic receptors
Destroyed in the gap before they get into he post-synaptic receptors
Taken up be post-synaptic receptors

Question 17

Structure of synapses

Answer 17

Most common types of synapses
Axodendritic ( axon terminal buttons on dendrites )
Axosomatic ( axon terminal buttons on soma / cell body )

But also
Dendritic spines ( axon terminal buttons on spines of dendrites)
Dendrodendritic ( dendrite to dendrite and often bidirectional transmission )
Axoaxonic ( can mediate presynaptic facilitation and inhibition of that button on the post-synaptic neurone )