Neurons

Question 1

What are the 3 ways to classify a neuron?

Answer 1

1. Motor (efferent)
2. Sensory (afferent)
3. Interneurons

Question 2

What are motor neurons?

Answer 2

Final neurons in action sequence
Located in motor nuclei of cranial nerves of the brain stem
Also found in the anterior horns of spinal cord

Question 3

What are the 2 types of motor neurons?

Answer 3

Alpha and Gamma

Question 4

Describe sensory neurons and which way to they move?

Answer 4

-From sensory receptors in body towards CNS
-First neurons in sensory sequence
-Cell bodies lie outside CNS (excpt for olfactory)

Question 5

4 components of a neuron?

Answer 5

1. Cell body
2. Axon
3. Axon terminal
4. Dendrites

Question 6

Describe the cell body (soma)…

Answer 6

Contains genetic information
Maintains neuron integrity/structure
Regulates production of proteins & lipids needed for energy

Question 7

Describe an axon

Answer 7

-Long and thin and spindly (way smaller than a human hair)
-Structure makes it suspectable to damage
-Where action potentials are generated and travel down to release neuro transmitters
-Axon covered in myelin
-Ends in Axon Terminals

Question 8

Describe dendrites

Answer 8

Receives the data from other neurons, and stores incoming information from axon terminals

Question 9

What is cytoplasm?

Answer 9

Jelly like fluid found within the cell body but outside the nucleolus
Function to transport, maintain cell shape, protect & hosts metabolic process

Question 10

Gray Matter

Answer 10

receives information & regulates outgoing information
Contains Cell bodies of neurons

Question 11

White matter

Answer 11

Sends info to brain, spinal column and body.

Question 12

Neuronal communication is either…

Answer 12

Excitatory or Inhibitory only

Question 13

Where do electrical signals occur?

Answer 13

within the neuron

Question 14

where do chemical signals occur?

Answer 14

between neurons

Question 15

What happens during neuronal communication?

Answer 15

Presynaptic neuron sends the information
Postsynaptic neuron receives the information

Question 16

Which neuron sends info?

Answer 16

Presynaptic neuron

Question 17

Which neuron receives info?

Answer 17

postsynaptic neuron

Question 18

What happens during soma movement of charged particles (ions)?

Answer 18

electrical signal sent down axon to the axon terminal (of presynaptic neuron)

Question 19

In neuronal communication, what is the created electric signal?

Answer 19

the action potential.

Question 20

After the action potential?

Answer 20

1.releases chemical (neurotransmitter),
2.which moves into the synaptic cleft,
3.binding to a receptor in the postsynaptic neuron,
4. causing ion channels to open.
5. The opening allows charged particles to cross membrane of that neuron causing electrical charge to form in the soma

Question 21

What is exocytosis?

Answer 21

When the presynaptic neuron axon terminals release a neurotransmitter that moves through synaptic cleft, binding to receptors of the postsynaptic neuron.

This created either an inhibitory response or an excitatory response.

Question 22

function of myelin?

Answer 22

insulates axon - voltage cannot change
charge jumps from node to node
Work to speed up the transmission of the impulse

Question 23

What are 2 important basal ganglia transmitters?

Answer 23

1. Dopamine
2. GABA

Question 24

Role of dopamine, and where is it produced

Answer 24

pleasures within reward system
-produced in substantia nigra located in midbrain just above brain stem
(one of 3 catecholamines)

Question 25

What is GABA, and where is it?

Answer 25

major inhibitory neurotransmitter
In brain and most output of basal ganglia

Question 26

Define neuropeptides?

Answer 26

-Hormones that can increase & decrease postsynaptic responses to a neurotransmitter
-long-lasting effect
-long time needed to replenish

Question 27

3 types of catecholamines?

Answer 27

1. norepinephrine - adrenal, contracts blood vessels
2. epinephrine - adrenal, dilates blood vessels to muscles
3. dopamine- pleasures within reward system produced in substantia nigra located in midbrain just above brain stem

Question 28

Fight or flight response?

Answer 28

catecholamines…increases BP, heart rate, slow digestion

Question 29

Role of glial cells?

Answer 29

Glial cells give physical and chemical support, nourish and coat neurons.
They clean away dead neurons from scar tissue.
They support young neurons.
Help maintain their environment.

(more glial cells than neurons)

Question 30

Where are glial cells found?

Answer 30

CNS & PNS

Question 31

What are the 5 types of glial cells?

Answer 31

1.Microglia
2.Astrocytes
3. Oligodendrocytes
4. Schwann
5. Ependymal

Question 32

Role of microglia?

Answer 32

Scavenge pathogens & dead cells

Question 33

Role of astrocytes?

Answer 33

provide nutrients, maintain extracellular environment & structural support

Question 34

Role of oligodendrocytes?

Answer 34

Form the myelin sheath, located in CNS.
swell in response to trauma

Question 35

Role of schwann?

Answer 35

form myelin in PNS

Question 36

Role of ependymal?

Answer 36

produces CSF

Question 37

Where is myelin made?

Answer 37

made by Schwann cells in the PNS
made by Oligodendrocytes in CNS

Question 38

What is myelin composed of (include percentage)

Answer 38

High proportion of lipids (70% -85%)
& lower proportion protein (15%-30%

Question 39

What are the nodes of Ranvier?

Answer 39

Gaps in myelin along axon

Question 40

What are synapses?

Answer 40

Tiny gaps where specialized parts of two neurons allow for chemical communication