Neurons Flashcards

(38 cards)

1
Q

What are neurons?

A

Nerve cells
Specialized cells that transmit messages

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2
Q

What are the major regions of neurons

A
  1. Cell body - nucleus and metabolic center of the cell
  2. Processes - fibers that extend from the cell body (Dendrites and axons)
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3
Q

What does the cell body include?

A

The nucleus and large nucleolus

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4
Q

What does the dendrites do?

A

They conduct impulses towards the cell body

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5
Q

What doe axons do?

A

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

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6
Q

What is an axonal terminal?

A

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

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7
Q

What is a synaptic cleft?

A

The gap between adjacent neurons

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8
Q

What is synapse

A

The junction between nerves (Includes the synaptic cleft)

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9
Q

What is gray matter?

A

Cell bodies within the white matter of the central nervous system

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10
Q

What is nuclei?

A

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

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11
Q

What is ganglia?

A

Collections of cell bodies outside the central nervous system

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12
Q

What are the three functional classification of neurons

A
  1. Sensory
  2. Relay
  3. Motor
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13
Q

What does a sensory neuron do?

A

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

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14
Q

What do relay neurons or interneurons do?

A

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

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15
Q

What do motor neurons do?

A

They carry impulses from CNS to effector

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16
Q

In what order would the neurons be used?

A
  1. The sensory neuron
  2. Association neuron
  3. Motor neuron
17
Q

What is a bipolar neuron

A

A neuron with one axon and one dendrite

18
Q

What is irritability?

A

The ability to respond to stimuli

19
Q

What is conductivity

A

The ability to transmit an impulse

20
Q

When the plasma membrane is at rest its…

A

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

21
Q

What is during depolarization?

A

A stimulus depolarizes the membrane

22
Q

What happens after depolarization?

A

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

23
Q

What does the exchange of ions allow?

A

It initiates an action potential in the neuron

24
Q

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

A

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

25
What restores the original configuration of the axon's polarity?
The sodium-potassium pump which pumps in the potassium forcing the sodium out, creating a negative polarity again
26
What makes the impulse travel faster?
A myelin sheath, which lets the impulse jump from node to node
27
What is a node? (Or node of ranvier)
The empty space between the myelin sheath, which carries the impulse across the axon
28
What does a neurotransmitter do?
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
29
What are astrocytes, what do they do?
They are abundant, star-shaped cells that form barrier between capillaries and neurons, they control the chemical environment of the brain (CNS)
30
What are microglia (CNS)?
They are spider-like phagocytes, they dispose of debris
31
What are ependymal cells (CNS)?
They are line cavities of the brain and spinal cord, and they circulate cerebrospinal fluid
32
What does an oligodendrocytes do?
It produces myelin sheaths around nerve fibers in the central nervous system
33
What does a satellite cell do?
It protects neuron cell bodies
34
What does a Schwann cell do?
It forms myelin sheath in the peripheral nervous system
35
What is the cyton?
It's the central, nucleus-containing part of a neuron
36
What is a neuromuscular junction?
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)
37
What is acetylcholine?
It function as a neurotransmitter
38
What does acetylcholine do?
When released from a synaptic knob it depolarizes the muscle cell membrane and trigger muscle contractions