Neurophysiology

Question 1

During it’s resting potential, the neuron is negative charged at ______

Answer 1

• 70mv

Question 2

An electrically charged atom, or particle that has lost or gained an electron (which gives it a positive or negative charge) is called an

Answer 2

Ion

Question 3

The inside of the neuron has

Answer 3

potassium ions

Question 4

The outside of the neuron has

Answer 4

sodium ions

Question 5

Embedded in the neuron membrane are a number of _________ that act as _________

Answer 5

specialised protein molecules, ion channels

Question 6

What is meant by diffusion forces (gradient)?

Answer 6

high concentration of ions are attracted to areas of low concentration or vice versa.

Question 7

What is meant by electrostatic forces (gradient)?

Answer 7

Positively charged ions are attracted to negative ones and vice versa.

Question 8

What is the function of the sodium-potassium pump?

Answer 8

maintain the intra and extra cellular balance of ions by a complex protein molecule located in the membrane.

Question 9

the sodium potassium pump forces out 3 sodium ions for every ______ it takes in.

Answer 9

2 potassium ions

Question 10

The sodium potassium pump forces out _______ for every 2 potassium ions it takes in.

Answer 10

3 sodium ions.

Question 11

What causes an action potential?

Answer 11

A sudden movement of sodium and potassium ions (+30mV)

Question 12

What is the threshold potential?

Answer 12

Triggering event is when resting potential becomes more positive by about +15mV

Question 13

Excitatory postsynaptic potential (EPSP) is when___

Answer 13

stimulation causes the voltage inside the cell to become more positive.

Question 14

Inhibitory postsynaptic potential (IPSP) is when ____

Answer 14

the cell becomes more negative.

Question 15

A neuron fires, or it doesn’t, this is called the

Answer 15

all-or-nothing principle

Question 16

A neuron cannot fire again during the ______ period

Answer 16

refractory

Question 17

When the neuron drops below -70mV after an action potential it is called?

Answer 17

refractory period

Question 18

Stimulation of the axonal receptors causing less neurotransmitters to be released by the presynaptic neuron is called?

Answer 18

presynaptic inhibition

Question 19

all neurotransmitters in the CNS are associated with ion channels in one of two ways:

Answer 19

1. ionotropic recepetors 2. metabotropic receptors

Question 20

When the receptor and ion channel form part of the same molecular unit it is called?

Answer 20

ionotropic receptors

Question 21

When the receptor and ion channels are separate entities they are called?

Answer 21

metabotropic receptors.

Question 22

Which cell is 10 times more common than brain neurone?

Answer 22

Glial cells

Question 23

A glial cell is ____ the size of a neuron.

Answer 23

one-tenth

Question 24

the Oligodendrocyte is a type of ____ cell.

Answer 24

Glial

Question 25

What is the function of the Oligondendrocyte?

Answer 25

it provides the myelin that covers the axons of most nerve fibres in the brain and spinal chord.

Question 26

In the peripheral nervous system, myelin is produced by the?

Answer 26

Schwann cell

Question 27

A function of the glial cell astrocyte is to?

Answer 27

provide a covering to the blood vessels of the brain which forms the blood-brain barrier

Question 28

What bars the entry of most larger molecules and toxins?

Answer 28

the blood-brain barrier

Question 29

Na+ stands for?

Answer 29

sodium

Question 30

K+ stands for?

Answer 30

potassium

Question 31

The movement of an action potential along the axon is called?

Answer 31

Nerve impulse

Question 32

Stimulation producing 2 EPSPs in quick succession illustrates?

Answer 32

temporal summation

Question 33

What are two characteristics of the postsynaptic membrane?

Answer 33

Thickened appearance and receptor proteins

Question 34

A key event in the release of neurotransmitter molecules into the synaptic cleft is the

Answer 34

influx of Ca++ions in response to the arrival of an action potential at the button or bouton.

Question 35

Neurotransmitters are produced in the

Answer 35

soma and synaptic terminals

Question 36

Dopamine, Serotonin and Norephinephrine are

Answer 36

Amine's

Question 37

Sympathetic neurons are

Answer 37

cholinergic and adrenergic

Question 38

Parasympathetic neurons are

Answer 38

cholinergic

Question 39

What is the function of GABA?

Answer 39

decreases the firing of cells

Question 40

A chemical in the postsynaptic cell that is activated by a G protein (after receptor stimulation) is called?

Answer 40

A second messenger

Question 41

Neurotransmitters are secreted from _________ in response to the arrival of an action potential.

Answer 41

axon terminal

Question 42

The process by which similarly charged particles repel each other and are thus distributed throughout a medium is termed?

Answer 42

electrostatic pressure

Question 43

What restores the membrane potential from the peak of the action potential back to its resting level?

Answer 43

Potassium ions move out of the cell

Question 44

Whenever the membrane potential reaches threshold what happens?

Answer 44

an action potential

Question 45

What prevents cross talk between adjacent neurone?

Answer 45

Myelin

Question 46

movement of the axon membrane potential from -70mV to -65mV is called?

Answer 46

depolarization