Basic Neurology: Cellular Anatomy

Question 1

glial cells

Answer 1

These cells serve varied functions, including providing support, and removal of neurotransmitters from the synaptic cleft.

Question 2

motor end plate

Answer 2

This refers to the end button/end bulb at the transition between the neuron and the muscle.

Question 3

astoglia

Answer 3

These star-shaped glial cells are important in transporting nutrients from capillaries to nerve cells

Question 4

synaptic vesicles

Answer 4

Neurotransmitters are stored in these vesicles, found at the terminal end buttons/end bulbs.

Question 5

microglia

Answer 5

These glial cells are macrophages, helping to destroy harmful organisms by engulfing them. They also clean up dead or damaged brain tissue.

Question 6

neurons

Answer 6

These are the basic building blocks of the nervous system. They are responsible for processing and transmitting messages throughout the entral and peripheral nervous systems.

Question 7

axon

Answer 7

The portion of the neuron that transmits information away from the soma.

Question 8

oligodendrocytes, oligodendroglia

Answer 8

Myelin sheaths within the central nervous system are produced by this type of glial cell.

Question 9

soma

Answer 9

The cell body of a neuron.

Question 10

synaptic cleft

Answer 10

The space between the end bulb/button and the next neuron’s soma or dendrite.

Question 11

dendrite

Answer 11

This portion of the neuron often has branch like extensions, which receive information from other neurons or sensors.

Question 12

neurotransmitters

Answer 12

These neurochemicals either transmit messages from neurons to other neurons, neurons to organs or muscles or act in a neuromodulatory role.

Question 13

telodendria, terminal branches

Answer 13

These are the thin, end branches of axons.

Question 14

multipolar

Answer 14

Most mammalian neurons have several dendrites and several axons. Thus their polarity is referred to as ________________.

Question 15

myelin

Answer 15

The role of this substance is to speed transmission of neural conduction and reduce degradation of signal.

Question 16

Schwann cells

Answer 16

Myelin sheaths within the peripheral nervous system are produced by this type of glial cell.

Question 17

terminal buttons

Answer 17

These are the tips or end bulbs of axons or telodendria.

Question 18

Nodes of Ranvier

Answer 18

These breaks between myelinated segments of myelinated axons are densely covered in sodium (Na) channels, allowing for regeneration of the action potential as it propagates down an axon.

Question 19

neuromuscular junction, neuromuscular end plate

Answer 19

This refers to the synaptic cleft between the motor end plate and the muscle itself.

Question 20

efferent (motor)

Answer 20

Motor pathways, which carry information from the CNS towards muscles or glands.

Question 21

interneurons

Answer 21

These cells connect neurons to other neurons, either locally or over long distances.

Question 22

afferent (sensory)

Answer 22

Sensory pathways, which carry information from sensory receptors toward the CNS.

Question 23

acetylcholine

Answer 23

This is the neurotransmitter responsible for sending messages across the neuromuscular junction.

Question 24

action potential

Answer 24

The process of stimulating a neuron adequately to produce a change in electrical potential allows for generation of a(n) ___________.

Question 25

resting membrane potential (RMP)

Answer 25

This refers to the condition of a neuron’s cell membrane at rest. It is polarized, which means there is a net negative charge in the intracellular space and a net positive charge in the extracellular space.

Question 26

Initiation of an action potential or spike leads to an influx of what ion?

Answer 26

sodium

Question 27

depolarization

Answer 27

A change in polarity. The influx of sodium contributes to __________ of the membrane.

Question 28

Once the action potential spike has peaked, what ion exits the cell in an effort to return to equilibrium or resting potential?

Answer 28

potassium

Question 29

repolarization

Answer 29

This is the process of returning a depolarized cell back towards equilibrium or resting potential.

Question 30

absolute refractory period

Answer 30

This refers to a period of time during which an action potential cannot be stimulated, no matter how strong the stimulus.

Question 31

relative refractory period

Answer 31

This refers to a period of time during which an action potential can only be stimulated with a strong stimulus.

Question 32

sodium-potassium ion pump

Answer 32

This structure actively transports ions across the neuron cell membrane in an effort to maintain a weighted equilibrium. It is responsible in part for returning a cell to its resting membrane potential following an action potential.

Question 33

diffusion

Answer 33

This refers to the process of ions moving freely along the concentration gradient. When ion gates are open, this ion movement can contribute to depolarization and repolarization of the cell membrane.

Question 34

saltatory condution

Answer 34

The process of transmitting an action potential from node to node. Gets its name from the prevalence of Na channels at the Nodes of Ranvier.

Question 35

Propagation down an unmyelinated axon requires successive opening and closing of ______ channels throughout the length of the axon.

Answer 35

ion

Question 36

temporal summation

Answer 36

This refers to the cumulative process of adding stimuli which occur in close time proximity to produce an action potential.

Question 37

spatial summation

Answer 37

This refers to the cumulative process of adding stimuli which occur in close physical proximity to produce an action potential.

Question 38

excitatory response

Answer 38

This refers to a message or stimuli, which excites another neuron.

Question 39

inhibitory response

Answer 39

This refers to a message or stimuli, which inhibits another neuron.

Question 40

pre-synaptic neuron

Answer 40

This refers to a message or stimuli, which inhibits another neuron.

Question 41

post-synaptic neuron

Answer 41

This refers to the neuron about to receive the message.

Question 42

the six main roles of glial cells

Answer 42

structure, transport nutrients, insulation, produce CSF, remove neurotransmitters from synaptic cleft, clean up injured/dead tissue