Neurons

Question 1

What are neurons?

Answer 1

Nerve cells
Specialized cells that transmit messages

Question 2

What are the major regions of neurons

Answer 2

1. Cell body - nucleus and metabolic center of the cell
2. Processes - fibers that extend from the cell body (Dendrites and axons)

Question 3

What does the cell body include?

Answer 3

The nucleus and large nucleolus

Question 4

What does the dendrites do?

Answer 4

They conduct impulses towards the cell body

Question 5

What do axons do?

Answer 5

(There is only 1 axon)
It conducts impulses away from the cell body

Question 6

What is an axonal terminal?

Answer 6

It is the end of an axon, they contain vesicles with neurotransmitters

Question 7

What is a synaptic cleft?

Answer 7

The gap between adjacent neurons

Question 8

What is synapse

Answer 8

The junction between nerves (Includes the synaptic cleft)

Question 9

What is gray matter?

Answer 9

Cell bodies within the white matter of the central nervous system

Question 10

What is nuclei?

Answer 10

clusters of cell bodies within the white matter of the central nervous system

Question 11

What is ganglia?

Answer 11

Collections of cell bodies outside the central nervous system

Question 12

What are the three functional classification of neurons

Answer 12

1. Sensory
2. Relay
3. Motor

Question 13

What does a sensory neuron do?

Answer 13

It carries impulses from receptors to the CNS
Example: Pain receptors in skin to the CNS

Question 14

What do relay neurons or interneurons do?

Answer 14

They carry impulses from sensory nerves to motor nerves. They are found in neural pathways in the CNS

Question 15

What do motor neurons do?

Answer 15

They carry impulses from CNS to effector

Question 16

In what order would the neurons be used?

Answer 16

1. The sensory neuron
2. Association neuron
3. Motor neuron

Question 17

What is a bipolar neuron

Answer 17

A neuron with one axon and one dendrite

Question 18

What is irritability?

Answer 18

The ability to respond to stimuli

Question 19

What is conductivity

Answer 19

The ability to transmit an impulse

Question 20

When the plasma membrane is at rest its…

Answer 20

Polarized, fewer positive ions are inside the cell than outside the cell

Question 21

What happens during depolarization?

Answer 21

A stimulus depolarizes the membrane

Question 22

What happens after depolarization?

Answer 22

The depolarized membrane allows sodium to flow inside the membrane (Sodium has a positive charge Na+)

Question 23

What does the exchange of ions allow?

Answer 23

It initiates an action potential in the neuron

Question 24

What allows for potassium ions to be rushed out of the neuron?

Answer 24

The action potential lets sodium ions rush in, repolarizing the membrane

Question 25

What restores the original configuration of the axon's polarity?

Answer 25

The sodium-potassium pump which pumps in the potassium forcing the sodium out, creating a negative polarity again

Question 26

What makes the impulse travel faster?

Answer 26

A myelin sheath, which lets the impulse jump from node to node

Question 27

What is a node? (Or node of ranvier)

Answer 27

The empty space between the myelin sheath, which carries the impulse across the axon

Question 28

What does a neurotransmitter do?

Answer 28

It is released from a nerves axon terminal and is accepted by the dendrite of another neuron, which have receptors that are stimulated by the neurotransmitter

Question 29

What are astrocytes, what do they do?

Answer 29

They are abundant, star-shaped cells that form barrier between capillaries and neurons, they control the chemical environment of the brain (CNS)

Question 30

What are microglia (CNS)?

Answer 30

They are spider-like phagocytes, they dispose of debris

Question 31

What are ependymal cells (CNS)?

Answer 31

They are line cavities of the brain and spinal cord, and they circulate cerebrospinal fluid

Question 32

What does an oligodendrocytes do?

Answer 32

It produces myelin sheaths around nerve fibers in the central nervous system

Question 33

What does a satellite cell do?

Answer 33

It protects neuron cell bodies

Question 34

What does a Schwann cell do?

Answer 34

It forms myelin sheath in the peripheral nervous system

Question 35

What is the cyton?

Answer 35

It's the central, nucleus-containing part of a neuron

Question 36

What is a neuromuscular junction?

Answer 36

It's a specialized synapse where a motor neuron communicates with a skeletal muscle fiber (It's the junction between a neuron and a muscle)

Question 37

What is acetylcholine?

Answer 37

It function as a neurotransmitter

Question 38

What does acetylcholine do?

Answer 38

When released from a synaptic knob it depolarizes the muscle cell membrane and trigger muscle contractions