Neurons

Question 1

2 Basic Functions of Cell Body/ Soma

Answer 1

1. Cellular Life- responsible for keeping cell alive and supports life of dendrites and axons.
2. Plays role of transmission of neural impulses.

Question 2

Axon Functions

Answer 2

Single long efferent process which conducts nerve impulses away from the cell body to either other neurons, muscles, or glands

Question 3

Axon Hillock

Answer 3

Where axon attaches to cell body and it’s where nerve impulses arrive

Question 4

Telodendria

Answer 4

Located at the end of an axon. Contains terminal boutons at the end.

Question 5

Terminal boutons

Answer 5

Located at the ends of each telodendria. They contain synaptic vessels.

Question 6

Synaptic Vessicles

Answer 6

These are where transmitters are stored.

Question 7

Dendrite Function

Answer 7

They are multiple short afferent processes that conduct impulses towards the cell body.

Question 8

Difference Between Myelin in PNS and Myelin in CNS

Answer 8

PNS: Myelin is made from neurolemmal cells. Many cells provide myelin for a single neuron. They grow around the point of injury so that the neuron can regenerate.
CNS: Made from Oligodendrocytes. One oligo dendrite provides myelin for several neurons. If a neuron gets injured, myelin condenses around the living ones and kicks out the dying one. Neurons in CNS don’t regenerate.

Question 9

Axons are Covered in What?

Answer 9

Myelin sheath, which is a fatty substance.

Question 10

Nodes of Ranvier and Function

Answer 10

Nodes of Ranvier are the gaps in the myelin sheath. Neural impulses jump from one to the next instead of traveling straight down. This causes the neural impulses travel quicker.

Question 11

Meaning of “We Equate the Myelination to Maturation of the Nervous System”

Answer 11

This means that people are not born myelinated. It takes 10-12 years. During this time, neural impulses travel straight down, which makes them slower and not as precise.

Question 12

3 Types of Neurons

Answer 12

1. Unipolar Neuron
2. Bipolar Neuron
3. Multipolar Neuron

Question 13

What is a Unipolar Neuron?

Answer 13

It is a single process that then divides into two processes. Afferent and efferent. Located in PNS.

Question 14

What is a Bipolar Neuron?

Answer 14

Multiple short processes off of one side of the neuron, and multiple processes off the opposite side. One acts as an axon, the other a dendrite. Located in PNS.

Question 15

What is a Multipolar Neuron?

Answer 15

Has a single axon off one pole and multiple short dendrites off the opposite pole. Located in CNS. (Stereotypical Neuron)

Question 16

Tracts and Function

Answer 16

Tracts are chains or bundles of neurons in CNS. They only carry one type of information. Either sensory or motor. Can’t do both.

Question 17

Nerves and function

Answer 17

Nerves are the chains or bundles of neurons in the PNS. They can carry sensory info, motor info, or both. Mixed nerves carry both.

Question 18

Neuron Transmission Pathway

Answer 18

The neuron has to be adequately stimulated. This generates a transitory electrochemical impulse that travels away from the point of excitation in a wavelike manner. It hops from one node of ranvier to the next, which is called saltatory conduction. This happens until it has reached the terminal point of the axon at which point, a specialized process begins. At the terminal boutons, synaptic vessels release neurotransmitters to the synaptic cleft. Once the neurotransmitters help the electrochemical impulse cross the cleft, the neurotransmitters go away.

Question 19

Synapse and its Three Parts

Answer 19

Neurons form functional unions with other structures, which are called synapses.
It has three parts: Presynaptic structure, synaptic cleft, and postsynaptic structure.

Question 20

Excitatory Effect

Answer 20

It’s an increase in stimulation. Neural impulses crosses to the next structure quicker, structure responds faster, and structure responds stronger.

Question 21

Inhibitory Effect

Answer 21

It’s a decrease in stimulation. The impulse crosses the cleft slower, the structure responds slower, and the structure’s response is dull or muted.

Question 22

Two Important Rules To Note About Neuron Transmission

Answer 22

1. Either the neuron is adequately stimulated, or it’s not.
2. Neural transmission happens on a one way street. Once it has started, it won’t stop until it reaches its destination or it is otherwise stopped.