Neurons

Question 1

Dendrites

Answer 1

• Short. thin, thread like branching from cell body
• Recieve stimulus
• Carry recieved nerves impulses toward CB

Question 2

Cell body

Answer 2

• Contains nucleus, mitochondria (enegry production)
• Coodriantes the neuron, produces chemical messengers

Question 3

Axon Hillock

Answer 3

• Swelling of cell body connecting to axon
• Orginates / triggers nerve impulse (action potential)

Question 4

Axon

Answer 4

• Long, thicker, single fibre
• 1 metre in length
  Carries electrical component of nerve impulse AWAY
• Larger diameter, faster speed of impulse
• Some covered with insulation myelin sheath

Question 5

Myelin Sheath

Answer 5

• Insulting white coating produced by Schwann cells
• White color
• allows faster movement of nerve impulse
• Nerves in brain and spinal
• WHITE matter (myelinated
• GREY matter (unmyelinated)

Question 6

Node of Ranvier

Answer 6

• Gaps between myelin sheath (1mm)
• ## Allows nerve impulses to travel faster down axon (120m/s)

Question 7

Synpathic knobs

Answer 7

• Bulb-like structure at end of nerve ending
• Transmits nerve impulses to another neuron
• Neuron transmitters

Question 8

Schwann Cell

Answer 8

• Type of gilal (support cells) that form myelin sheath around axons in PNS

Question 9

Neurilemma

Answer 9

• Thin outer membrance on axon of some neurons formed by Schwann cells
• Promotes the regeneration of damaged axons after injury
• No nuerilemma = no recovery
• In PNS but not CNS

Question 10

Overall movement of Nerve Impulse

Answer 10

Dendrites -> Cell Body -> Axon Hillock -> Axon -> Terminal Branches -> Synaptic Knobs

Question 11

Gilal Cells

Answer 11

• strucal support and metabolism
• Form myelin sheath : Schwann cells form of gilal cell
• Remove waste
• Fill empty space and guide nerve growth

Question 12

Mutliple Sclerosis (MS)

Answer 12

• Autoimmue disease = body break downs own Immune system break down myelin
• Destruction of myelin = inefficent nerve transmisson
• Myelin in brain and spinal cord destoryed and hardens, forming scars causing, Genetics, Viruses, Enviroment

Question 13

Symptoms of MS

Answer 13

double vision, jerky limb movements, lack coordination, weakness, partial paralysis,

Question 14

Treatment of MS

Answer 14

Wheelchairs, medications to stop myelin destructions, leg braces, phycial therapy, NO CURE