Neurons and Glia Part I

Question 1

function of dendrites

Answer 1

receives electrical and chemical messages from other neurons

Question 2

cell body

Answer 2

processes incoming signals and generates outgoing signals

Question 3

axons

Answer 3

sends outgoing signals to axon terminals

Question 4

axon terminal

Answer 4

make contact with nearby cells and transmit signals to them

Question 5

what is glial cell

Answer 5

single glial cell wraps itself around an axon to form a segment of the myelin sheath and provides physical and chemical support to neurons and maintain their environmenta

Question 6

What determines the resting membrane potential of a neuron?

Answer 6

the concentration of ions (K+, Na+, Ca++, Cl-), the lipid bilayer, and proteins spanning the membrane.

Question 7

Which ions have higher concentrations inside and outside the neuron, contributing to the resting membrane potential?

Answer 7

The concentration of potassium ions (K+) is slightly higher inside the neuron, while the concentration of sodium ions (Na+) is slightly higher outside the cell membrane

Question 8

How is the resting membrane potential maintained?

Answer 8

The Na+/K+ ATPase actively transports three sodium ions out of the cell in exchange for two potassium ions into the cell.

Question 9

What triggers the initiation of an action potential?

Answer 9

Stimulation of the membrane to the threshold level, causing voltage-gated Na+ channels to open.

Question 10

What happens during depolarization in an action potential?

Answer 10

Voltage-gated Na+ channels open, leading to a rapid influx of Na+ ions and membrane depolarization.

Question 11

How is repolarization achieved after depolarization?

Answer 11

Voltage inactivation of Na+ channels and voltage activation of K+ channels result in efflux of K+ ions, driving the membrane potential back below zero

Question 12

How would you describe the nature of an action potential?

Answer 12

An “all-or-nothing” response with a set amplitude.

Question 13

What are graded potentials, and how do they differ from action potentials?

Answer 13

Graded potentials are local changes in membrane potential that degrade with distance, unlike action potentials, which maintain a set amplitude and allow communication between neuron’s.

Question 14

How do neurons use changes in their membrane potential?

Answer 14

Neurons use changes in membrane potential as signals to receive, integrate, and send information.

Question 15

What is necessary for the generation of a nerve impulse (action potential)?

Answer 15

Voltage-gated ion channels on the neuron’s membrane

Question 16

What is the difference between continuous and saltatory conduction?

Answer 16

continuous conduction occurs along the entire length of an unmyelinated axon, while saltatory conduction “skips” along myelinated axons, making it faster and more efficient.

Question 17

What is the significance of Nodes of Ranvier in saltatory conduction?

Answer 17

Nodes of Ranvier, rich in Na+ and K+ channels, allow the action potential to jump from one node to the next along the axon, facilitating rapid conduction.

Question 18

Which cells are responsible for myelination in the nervous system?

Answer 18

Oligodendrocytes (in the central nervous system) and Schwann cells (in the peripheral nervous system) are myelinating glia.

Question 19

where is oliogodendrocytes are found?

Answer 19

CNS

Question 20

Where is Schwann cells found?

Answer 20

PNS