Neural structure and function

Question 1

William, a philosophy student, asked Ian the psychology student what type of cell contributes the most to Ian’s thoughts, feelings, and actions. Without hesitation, Ian replied ______.

Answer 1

neurons

Question 2

What is the fundamental concept of the Neuron Hypothesis?

Answer 2

Individual neurons represent the fundamental building blocks of the nervous system.

Question 3

What are neurons specialized for?

Answer 3

communcation

Question 4

What electrical property do all cells, including neurons, have?

Answer 4

Charged ions moving in and out.

Question 5

What is the difference in voltage inside/outside the cell known as?

Answer 5

Membrane potential (MP).

Question 6

What is the typical resting potential of a neuron?

Answer 6

-70mV.

Question 7

What maintains the negative charge inside a neuron?

Answer 7

A balance of positive and negative ions.

Question 8

What ions are more concentrated outside and inside the neuron, respectively?

Answer 8

Sodium (Na+) outside; Potassium (K+) inside.

Question 9

What is the process called when a neuron receives signals from other neurons?

Answer 9

Summation.

Question 10

What is an action potential?

Answer 10

A nerve impulse characterized by a rise and fall in electrical membrane potential.

Question 11

What happens during depolarization in an action potential?

Answer 11

Na+ ions flood into the cell, increasing the membrane potential.

Question 12

What triggers the action potential?

Answer 12

If the threshold of -55mV is reached.

Question 13

What occurs during repolarization of an action potential?

Answer 13

K+ ions flood out, reducing the membrane potential.

Question 14

What is the ‘all or nothing principle’ in relation to action potentials?

Answer 14

An action potential is a fixed size and either occurs fully or not at all.

Question 15

Who first worked out how action potentials are generated?

Answer 15

Hodgkin and Huxley.

Question 16

What is a synapse?

Answer 16

A chemical junction between neurons.

Question 17

What types of neurotransmitters are classified as excitatory and inhibitory?

Answer 17

• Glutamate → Excitatory
• GABA → Inhibitory

Question 18

What role do microglia play in the nervous system?

Answer 18

Immune function.

Question 19

What is the role of astrocytes?

Answer 19

Control NT levels, modulate neuron function and synapses.

Question 20

What neurotransmitter is associated with muscle control and memory regulation?

Answer 20

Acetylcholine.

Question 21

What is the primary function of dopamine?

Answer 21

Produces feelings of pleasure and is involved in motivation and addiction.

Question 22

What effect does alcohol have on neurotransmission?

Answer 22

Acts as a depressant, enhancing GABA transmission and inhibiting glutamate.

Question 23

What is the role of cocaine in neurotransmission?

Answer 23

Prevents dopamine reuptake.

Question 24

What is neurodegeneration?

Answer 24

Progressive loss of neurons due to underlying disease conditions.

Question 25

What characterizes Parkinson's disease?

Answer 25

Loss of dopaminergic neurons in the substantia nigra.

Question 26

What does the autonomic nervous system regulate?

Answer 26

Functions such as heart rate, respiratory rate, and digestion.

Question 27

What is the role of the pituitary gland in the endocrine system?

Answer 27

It is the 'master gland' that controls other glands.

Question 28

How do the nervous system and endocrine system generally differ in speed?

Answer 28

Nervous system = fast; Endocrine system = slow.

Question 29

Fill in the blank: The inside of a neuron is more _______ charged compared to the outside.

Answer 29

negatively

Question 30

True or False: Neurotransmitters can only excite neighboring neurons.

Answer 30

False.

Question 31

What are the two divisions of the autonomic nervous system?

Answer 31

* Sympathetic: ‘fight or flight’ * Parasympathetic: ‘rest and digest’

Question 32

What type of receptors does nicotine bind to?

Answer 32

Acetylcholine receptors (nicotinic receptors).

Question 33

What is the effect of psychedelics like LSD on the brain?

Answer 33

They distort perception, cognition, and mood.

Question 34

What happens when we lose neurons?

Answer 34

Loss of function.

Question 35

what is the typical resting potential of neuron

Answer 35

-70mV

Question 36

example of a molecule that can diffuse in and out

Answer 36

h2o

Question 37

what is a semi permeable membrane

Answer 37

thin sheets that allow some molecules to pass through easier than others

Question 38

what triggers action potential

Answer 38

depolarisation reaching threshold 9~55mV), causing Na+ to flood in

Question 39

what is repolarisation

Answer 39

K+ ions flow out of the neuron, restoring negative internal change

Question 40

what is the refractory period

Answer 40

a short time after an action potential when a neuron can't fire again

Question 41

how fast do signals travel

Answer 41

myelinated: ~100m/s unmyelinated: ~1m/s

Question 42

what is a synapse

Answer 42

a chemical junction where neurotransmitters transfer signals between neurons

Question 43

most common excitatory neurotransmitter

Answer 43

glutamate

Question 44

most common inhibitory neurotransmitter

Answer 44

GABA

Question 45

what does acetylcholine do

Answer 45

controls muscles and supports memory

Question 46

is acetylcholine excitatory or inhibitory

Answer 46

usually excitatory

Question 47

what does dopamine do

Answer 47

pleasure, motivation, reward

Question 48

is dopamine excitatory or inhibitory

Answer 48

can be both

Question 49

what does serotonin regulate

Answer 49

mood, appetite, sleep

Question 50

what is an agonist

Answer 50

a compound that mimics or increases a neurotransmitters effects

Question 51

what is an antagonist

Answer 51

a compound that blocks or reduces a neurotransmitters effects

Question 52

how does cocaine work

Answer 52

blocks dopamine reuptake (which also affects serotonin and norepinephrine)

Question 53

how does nicotine work

Answer 53

binds to acetylcholine receptors (nicotinic)

Question 54

how does caffiene work

Answer 54

antagonist for adenosine receptors (keeps you alert)

Question 55

how do psychedelics affect the brain

Answer 55

act mostly on serotonin receptors, altering perception and mood

Question 56

what are glial cells

Answer 56

non-neuronal cells that support neurons

Question 57

name three types of glial cells

Answer 57

1. microglia 2. astrocytes 3. oligodendrocytes

Question 58

role of microglia

Answer 58

immune response

Question 59

role of astrocytes

Answer 59

regulate neurotransmitters

Question 60

role of oligodendrocytes

Answer 60

produce myelin in the CNS (Schwann cells in PNS)

Question 61

what is the function of autonomic nervous system

Answer 61

regulates involuntary functions (e,g. heart rate and digestion)

Question 62

what is neurodegeneration

Answer 62

progressive loss of neurons leading to functional decline

Question 63

what happens in Parkinson's disease

Answer 63

loss of dopaminergic neurons in the substantial nigra (basal ganglia), leading to motor and cognitive issues

Question 64

The ______ potential is the neuron’s means of transmitting information over long distances.

Answer 64

action

Question 65

The ______ is the difference in electrical potential between the inside and outside of an inactive neuron.

Answer 65

resting

Question 66

The gaps in the myelin sheaths on axons are known as:

Answer 66

nodes of ranvier

Question 67

Which of the following concepts does the all-or-nothing law describe?

Answer 67

The size of an action potential does not depend on the amplitude of the stimulus that started it.

Question 68

what is synaptic cleft

Answer 68

microscopic area between presynaptic and postsynaptic neurons

Question 69

how wide is synaptic cleft

Answer 69

around 40nm

Question 70

what is the presynaptic neuron

Answer 70

neuron where signal is initiated

Question 71

what is the postsynaptic neuron

Answer 71

neuron that receives the signal

Question 72

what are vesicles

Answer 72

found in presynaptic neuron, contain thousands of NTs

Question 73

what happens after a presynaptic neuron is excited by an action potential

Answer 73

vesicles fuse fuse with presynaptic membrane and release contents into the synaptic cleft, then onto the receptors of the postsynaptic neuron

Question 74

what is diffusion

Answer 74

when NT molecules drift out from the synaptic cleft

Question 75

what is reuptake

Answer 75

where NT molecules are taken back to the presynaptic neuron to be reused