Lecture 6

Question 1

What are the main parts of a neuron?

Answer 1

Soma, Nucleus, Membrane

These parts are common to all human cells.

Question 2

What is the function of the soma in a neuron?

Answer 2

Acts like a factory where proteins and neurotransmitters are manufactured

Contains all of the organelles.

Question 3

What does the nucleus of a neuron contain?

Answer 3

The genetic material of the cell.

Question 4

What is the role of the membrane in a neuron?

Answer 4

Controls ion flow, signal reception, and cell communication for neuron function.

Question 5

What specialized parts do neurons have that are not found in other cell types?

Answer 5

Axons, Dendrites, Myelin sheath, Axon terminals.

Question 6

What is the function of dendrites?

Answer 6

Gather much of the information incoming from other cells.

Question 7

What are dendritic spines?

Answer 7

Small, protruding structures on dendrites that act as a receiving point for chemicals released by other neurons.

Question 8

What is an axon?

Answer 8

A long, slender, fiber-like extension of a neuron that conducts electrical impulses away from the cell body.

Question 9

How many axons does each neuron have?

Answer 9

Each cell has only one axon.

Question 10

What is the myelin sheath?

Answer 10

An insulating material that speeds up action potentials.

Question 11

What cells produce myelin in the Central Nervous System?

Answer 11

Oligodendrocytes.

Question 12

What cells produce myelin in the Peripheral Nervous System?

Answer 12

Schwann Cells.

Question 13

What are nodes of Ranvier?

Answer 13

Regularly spaced gaps in the myelin sheath surrounding the axon of a neuron.

Question 14

What disease is caused by the loss of myelin around neuronal axons?

Answer 14

Multiple Sclerosis.

Question 15

What is resting potential?

Answer 15

The baseline electrical charge across a neuron’s membrane when at rest, about -70 millivolts.

Question 16

What two features maintain resting potential?

Answer 16

• Ion Channels
• Sodium Potassium Pump.

Question 17

What is an action potential?

Answer 17

A very brief shift in a neuron’s electrical charge that travels along an axon.

Question 18

What happens to the electrical charge during an action potential?

Answer 18

Reverses from about -70mv to about +30mv, known as depolarization.

Question 19

What is the all-or-none law in neurons?

Answer 19

Neurons either fire an action potential or they don’t.

Question 20

What is the absolute refractory period?

Answer 20

The minimum length of time after an action potential during which another action potential cannot begin.

Question 21

What is a synapse?

Answer 21

A specialized junction between two neurons that allows for the transfer of electrochemical signals.

Question 22

What is the synaptic gap?

Answer 22

The small space between the axon terminal of a pre-synaptic neuron and the post-synaptic neuron.

Question 23

What are neurotransmitters?

Answer 23

Chemical messengers that facilitate communication between neurons.

Question 24

What are the eight key stages involved in neurotransmission?

Answer 24

• Synthesis
• Transportation and storage
• Release
• Binding
• Deactivation
• Autoreceptor activation
• Reuptake
• Degradation.

Question 25

What is synthesis in neurotransmission?

Answer 25

The process by which the body produces neurotransmitters.

Question 26

What are synaptic vesicles?

Answer 26

Small structures within a neuron that store neurotransmitters.

Question 27

What triggers the release of neurotransmitters?

Answer 27

Action potentials.

Question 28

What is exocytosis?

Answer 28

The process of moving molecules from within a cell to the exterior of the cell.

Question 29

What occurs when neurotransmitters bind to receptors on the post-synaptic cell?

Answer 29

They can either excite or inhibit the neuron.

Question 30

What is deactivation in neurotransmission?

Answer 30

The process of terminating or reducing the effects of a neurotransmitter in the synaptic cleft.

Question 31

What are the three main processes by which neurotransmitters are eliminated from the synapse?

Answer 31

* Diffusion * Reuptake * Degradation.

Question 32

What are autoreceptors?

Answer 32

Receptors on the releasing (pre-synaptic) neuron that help regulate neurotransmission.

Question 33

What is reuptake?

Answer 33

The reabsorption of a neurotransmitter by the presynaptic neuron after it has been released.

Question 34

What is enzymatic degradation?

Answer 34

When enzymes in the synaptic cleft break down neurotransmitter molecules into inactive byproducts.

Question 35

What are the four common properties of neurotransmitters?

Answer 35

* Synthesized in the neuron * Stored in the synaptic terminals * Released during an action potential * Deactivated/removed from the synapse after neurotransmission.

Question 36

What is GABA?

Answer 36

The primary inhibitory neurotransmitter in the brain.

Question 37

What is glutamate?

Answer 37

The primary excitatory neurotransmitter in the brain.

Question 38

What are monoamines?

Answer 38

A group of neurotransmitters including dopamine, noradrenaline, and serotonin.

Question 39

What role does dopamine play?

Answer 39

Involved in movement and reward.

Question 40

What is the function of noradrenaline?

Answer 40

Mobilizes the brain and body for action, increases attention and vigilance.

Question 41

What is serotonin involved in?

Answer 41

Many complex behaviors/cognitions including sleep, mood, and memory.

Question 42

What happens when dopaminergic neurons become damaged?

Answer 42

It leads to Parkinson’s Disease.

Question 43

What neurotransmitter is involved in movement and reward, released during eating and sex?

Answer 43

Dopamine ## Footnote Dopamine plays a crucial role in pleasure and reward mechanisms in the brain.

Question 44

What is the function of noradrenaline?

Answer 44

Mobilizes the brain and body for action, increases attention and vigilance ## Footnote It is released during stress or fear as part of the fight-or-flight response.

Question 45

Which neurotransmitter is involved in complex behaviors such as sleep, mood, and memory?

Answer 45

Serotonin ## Footnote Serotonin plays a key role in regulating mood and cognitive functions.

Question 46

What is Parkinson's Disease characterized by?

Answer 46

Tremors, slowness of movement, muscle stiffness, and balance problems ## Footnote Parkinson's Disease results from damage to dopamine-secreting neurons.

Question 47

What class of drugs targets serotonin and is used to treat depression?

Answer 47

Selective Serotonin Reuptake Inhibitors (SSRIs) ## Footnote SSRIs work by blocking serotonin reuptake, increasing serotonin levels in the synaptic gap.

Question 48

How is norepinephrine synthesized?

Answer 48

From dopamine ## Footnote Norepinephrine acts as both a neurotransmitter and a hormone.

Question 49

What types of drugs typically target norepinephrine?

Answer 49

Drugs for Attention Deficit Disorders ## Footnote Examples include amphetamines, which increase norepinephrine levels in the brain.

Question 50

What is the primary role of acetylcholine (ACh)?

Answer 50

Transmitter between motor neurons and voluntary muscles ## Footnote ACh is essential for all voluntary movements, including walking and talking.

Question 51

What system is acetylcholine the primary neurotransmitter for?

Answer 51

Parasympathetic nervous system ## Footnote This system is responsible for rest, digestion, and slowing the heart rate.

Question 52

What type of poisons block acetylcholine?

Answer 52

Some poisons, such as Atropa belladonna ## Footnote Atropa belladonna is known as 'deadly nightshade' and can interfere with ACh signaling.