Neurophysiology

Question 1

Neuron

Answer 1

The brain collects and processes information coming from inside and outside the body and then issues commands by means of neurons. There are 100 billion in the human brain

Question 2

Dendrites

Answer 2

• Thousands per neuron

- receive information from other neurons.

Question 3

Axon

Answer 3

• Usually only 1 per neuron

- Send information to other neurons

Question 4

Myelin Sheath

Answer 4

• Covering substance of a neuron

- Causes nerve impulse to travel rapidly down a neuron

Question 5

Nodes of Ranvier

Answer 5

-Gaps in myelin an axon

Question 6

Action Potential

Answer 6

Neurons communicate via a membrane excitability process known as an action potential or nerve impulse

Question 7

Axon Hillock

Answer 7

Incoming signals from other neurons is held at the axon hiilock

Question 8

Propagation

Answer 8

Movement of an action potential along an axon after stimulation pf the membrane potential

Question 9

Saltaory Conduction

Answer 9

Rapid conduction of an action potential

Question 10

Neurotransmitter

Answer 10

Flow of this substance converts the electrical signal into a chemical signal

Question 11

Synaptic Cleft

Answer 11

Gap between 2 neurons

Question 12

Postsynaptic Membrane

Answer 12

Cell membrane receiving the coded message

Question 13

Synaptic Potential

Answer 13

The composition of the chemical signal and its binding to the post synaptic membrane determines whether the information serves to depolarize or hyperpolarize the postsynaptic membrane

Question 14

Local Process

Answer 14

• A single input potential insufficient to produce an action potential
• Numerous local potentials collected at the axon hillock will sufficiently produce an action potential

Question 15

All or none principle

Answer 15

Neurons are sufficiently stimulated to produce and action potential or not stimulated enough

Question 16

Resting Membrane Potential

Answer 16

• Neuron is not generating an action potential -65mv
• Positive (+) charge
• outside the cell membrane
• Negative (-) charge
  
  • Inside of cell membrane

Question 17

Depolarization

Answer 17

Reduction in the negative charge inside the neuron by the flow pf possibility charged ions such as Na+

Question 18

Hyperpolorization

Answer 18

Increase in the negative charge inside the neuron by the flow of positively charged ions like K+ outside of the neuron (efflux) or flow of negatively charged ions into the neuron (influx)

Question 19

Excitatory Postsynaptic Potential (EPSP)

Answer 19

A depolarized graded potential that drives the membrane potential Towards the threshold and excites the neurons

Question 20

Inhibitory Postsynaptic Potential (IPSP)

Answer 20

A hyperpolarized graded potential that drives the membrane potential away from the threshold and inhibits the neuron.

Question 21

Relative Refractory Period

Answer 21

Time after the action potential has occurred when the neuron is hyperpolarized and more inputs are needed to ,make the neuron fire again

Question 22

Volume Conduction

Answer 22

Current flowing between the electrical generator and recording electrodes through scalp, skull and brain