CH3 - neural networks

Question 1

Parts of a neuron

Answer 1

• soma: cell main body. decides whether to fire more or less 9excitatory vs inhibitory)
• Dendrites: atatched to soma like branches, recieve electrical signal from neighbouring neruons. (contains post synaptic cleft). they have NT receptors
• axon hillock (connection between soma and axon)
• axon: only one on each neuron. transmits signal down length via ion chanels (propogates AP)
• axon terminal: containes vesiciles (which have NT) the branched part of the other side of neuron
• terminal buttons: contain many vesicles that release NT. presynaptic cleft that pass signal to next neuron
• nodes of ranvier: gaps in myelin that allowes charges oto jump node to node. propogates action potentail down axon

Question 2

the synapse

Answer 2

gap between neuron junctions

Question 3

glial cells (astrocytes, micoglia, oligodendrocytes and schwann cells)

Answer 3

• support cells
  -10:1 ration to neurons
• provide nutrients, remove waste, structureal cells, form myelin
• astrocytes: form immune system of brain. fight infections. remove waste. structural support + provides nutrients. when dysfucntional: lead to neurodegenerative diseases
• microglia: form immune system of brain, fight infections, remove waste,
• oligodendrocytes: form myelin around axons in CNS transmission of messgaes
• schwanna cells: form myelin around axons in PNS. speed up transmission of message

Question 4

Action Potential steps (explain in details)

Answer 4

1. resting membrane potential
2. depolarizatin
3. repolarization,
4. hyperpolairzation then refractory period
   (failed initiation)

Question 5

what is a Neurotransmitter and how works

Answer 5

• chemicals that travel across synapse
• excitatory (increase chance of AP) and inhibitory
• vesicale binds to postsynaptic membran to release NT

Question 6

types of NT’s + theyre associated drugs (AD)

Answer 6

Excitatory:
- ACh (allows NA+ to flow in) receptors located on muscle contractions. distruption linked to alzhemiers (AD: botox)
- Glutamate: affects learning and function (AD: PCD, ketamine)

Inhibitaory
- GABA: allows in CL- to flow in. controls anxiety and learning. (AD: valium)

I/E
- Dopamine: elevation/depression of mood (AD:cocaine - prolongs effect of dopamine)
- Seratonin: elevation and depression of mood (AD: prozac)

Question 7

Drugs: antagonist, agonist, partial

Answer 7

agonist
- molecule that mimics natural NT
- cocaine
-direct agonist: competes with NT at receptor (morphine, fentanyl)
- indirect agonist: does not compete with NT at receptor. exert influence from afar (cocaine) (prolongs effect of natural NT without replacing it)

antagonist
- moleucle that blocks a NT actions
- blocks receptor and does not function
- ex: botox