Mod 11: Neuron Anatomy And Physio

Question 1

What are the two basic types of cells?

Answer 1

Neurons and neurolgia

Question 2

What are the neurons function?.

Answer 2

Conduct signals in the NS and serve all sensorimotor activities and higher cortical functions

Question 3

Neuroglia are

Answer 3

Supporting and insulating cells

Question 4

What do Schwann cells do

Answer 4

Form and lay down the myelin sheath on peripheral nerves and form the axon covering

Question 5

What are the 3 types of neuroglia in the CNS?

Answer 5

1. Oligodendroglia
2. Astroglia
3. Microglia

Question 6

What is the oligodendroglia function

Answer 6

Form and lay down myelin sheath

Question 7

What is the function of Astroglia

Answer 7

Occupy spaces between neural processes in the gray matter and insulate the synapse

Question 8

What do the microglia function as

Answer 8

Macrophages- remove cell debris

Question 9

Where is the action potential initiated?

Answer 9

axon hillock

Question 10

Where do each main axon terminate

Answer 10

Terminates by branching into several terminal processes = telodendron

Question 11

What does the bouton contain?

Answer 11

Vesicles that contain neurotransmitters substance

- excitatory and inhibitory

Question 12

Where do each telodendron end

Answer 12

Terminal bouton

Question 13

Neurons can be classified by what 2 features?.

Answer 13

The number of processes they have and the length of the neuron

Question 14

What are the 3 types or classes of neurons

Answer 14

1. Multipolar neuron
2. Bipolar neuron
3. Unipolar neuron

Question 15

Most ____ neurons are found in the brain

Answer 15

Multipolar

Question 16

The bipolar neuron has 2 processes, the dendrite is the _____process and the axon is the _____ process

Answer 16

Peripheral; central

Question 17

Which neuron is the ‘T-shaped’ neuron

Answer 17

Unipolar neuron

Question 18

Neurotransmitters are produced by ____ with in the cell’s neuroplasm

Answer 18

Mitochondria

Question 19

What is the space that exists between the bouton of one neuron and the cell body, dendrite or axon of another neuron

Answer 19

Synaptic cleft

Question 20

T/f: neuroaaxonal is the site of contact between axon (bouton) and soma or dendrite of 2nd neuron

Answer 20

False: neurosomatic

Question 21

The internode is the

Answer 21

Distance between nodes

Question 22

T/F: The membrane potential in a neuron is about +70mv

Answer 22

False: -70mv

Cell membrane is also polarized at -70mv

Question 23

Inside the cells there is a high concentration of

Answer 23

Potassium and anions

Question 24

Outside the cel there is a high concentration of

Answer 24

Sodium ions and chloride ions

Question 25

T/F: resting cell membrane is somewhat impermeable to potassium but very permeable to sodium ions

Answer 25

False; impermeable to sodium ions and very permeable to potassium

Question 26

What is an action potential?

Answer 26

The nerve impulse
Can be elicited by nerve fibers by any factor that suddenly increase the permeability of the cell membrane to sodium ions

Question 27

What are AP’s elicited by

Answer 27

A physical or chemical stimulus

Question 28

To trigger an AP, the membrane potential must become more positive by ____mv

Answer 28

10

Question 29

How does the membrane potential become more positive when AP is elicited

Answer 29

Sodium leaks into the cell

Question 30

The return to the membrane potential to its resting state is called

Answer 30

Repolarization

Question 31

____ is the initial positive change in membrane potential that occurs in preparation for AP

Answer 31

Depolarization

Question 32

When does the refractory period occur?

Answer 32

After AP is triggered

Question 33

What are the two components of the refractory period

Answer 33

1. Absolute - new AP can’t be generated; neuron is hyperpolarized and negative
2. Relative - a strong stimulus can cause a new AP, membrane not fully repolarized

Question 34

T/F: AP is an all-or-nothing phenomenon

Answer 34

True, fires or not

Question 35

What are the two types of neural stimulation

Answer 35

Temporal and spatial

Question 36

What needs to occur to generate a new AP

Answer 36

An arriving stimulus needs to reach the initial segment (axon of hillock) of the neuron and a greater generator potential need to sum

Question 37

A ____ stimulus evokes a small potential

Answer 37

Weak

Question 38

The excitation of the receptor membrane makes the post-synaptic membrane more ____

Answer 38

Positive

Question 39

What’s the difference between the inhibitory an excitatory post-synaptic potential

Answer 39

Inhibitory prevents a developmental of generator potential, decreasing an new AP
Excitatory generates a local graded response to facilitate a AP