Cells To The NS

Question 1

Nerve tissue consists of:

Answer 1

Neurons and nueroglia(glial cells)

Question 2

Name the five functions of neuroglia. Hint:M_2p’s_2r’s

Answer 2

1. Maintain physical structure of the tissues
2. Perform phagocytosis
3. Provide nutrients to neurons
4. Repair tissue framework after injury
5. Regulate the composition of the interstitial fluid

Question 3

Name 3 parts of a neuron.

Answer 3

1. Dendrites
2. Cell body
3. Axon

Question 4

Towards where do the dendrites signal?

Answer 4

Cell body

Question 5

Cell body contains of what and also produces what which is stored in what?

Answer 5

Nucleus( containing genetic info) and other things found in most cells.

Neurotransmitters

Synaptic vesicles

Question 6

Explain what is an axon hillock.

Answer 6

Is the 1st part of the axon plus the part of the cell body where the axon exits.

It has the lowest threshold for AP.

Part where AP are initiated

Question 7

Towards where does the axon signal?

Answer 7

Away from cell body

Question 8

Other name for axon.

Answer 8

Nerve fiber

Question 9

An axon is a single tube like fiber that is shorter/longer and thicker/slimmer than dendrites.

Answer 9

Longer,thicker

Question 10

Neurons use axons to transmit an electrical/chemical l impulse to other neurons?

Answer 10

Electrical impulse

Question 11

Is an axon terminal the BEGINNING/END of an axon?

Answer 11

End

Question 12

Which neuron sends information from the sensory organs, through the spinal nerves, into the CNS?

Answer 12

Sensory (afferent) neuron

Question 13

Which neuron carries messages from the CNS, through spinal nerves, to operate muscles and glands?

Answer 13

Motor(efferent) neuron

Question 14

Which neuron exists only within the CNS, that carry messages from 1 set of neurons to the other. They can bring information from different sources together into one location in the CNS.

Answer 14

Interneurons

Question 15

Give the types of CNS neuroglia. Hint: Aw’O ME

Answer 15

Astrocytes
Oligodendroglia
Microglia
Ependymal

Question 16

Name the types of neuroglia cells that “ digest parts of dead neurons “ phagocytic cells.

Answer 16

Astrocytes and Microglia(only function)

Question 17

Give the types of PNS neuroglia. Hint:SS

Answer 17

Schwann and Satellite

Question 18

Which neuroglia cells “provide insulation(myelin) to neurons in the CNS AND THE OTHER IN THE PNS?

Answer 18

CNS- oligodendroglia

PNS- Schwann

Question 19

Satellite gives “physical support to neurons in the CNS/PNS?

Answer 19

PNS (peripheral nervous system)

Question 20

Ependymal cells line the____of the brain and produce____.

Answer 20

Ventricles and CSF

Question 21

Name the two kinds of signaling mechanisms.

Answer 21

Electrical and chemical signals

Question 22

Explain what is an electrical signal?

Answer 22

Is an INTRAneuronal signal that transmits Action

Potential along the axon and Graded Potentials

in the postsynaptic membrane , which cause an

Action Potential, stimulated by Resting Membrane

Potential.

Question 23

Name the components of the basic reflex arch.

Answer 23

E.g Patellar tendon

1. Stimulus
2. Receptors
3. Sensory neuron
4. Spinal cord
5. Motor neuron
6. Effector muscle
7. Response

Question 24

Give the whole scenario when stimulus is stretched muscle. Hint:5 steps

Answer 24

1. Graded potentials in the stretch receptor ending
2. Action potentials conducted to CNS
3. Action potentials converted to graded transmitters release.
4. Graded postsynaptic potentials in motor neuron
5. Action potentials conducted to muscle

Which then response in muscle contracting

Question 25

What is membrane potential?

Answer 25

Is the voltage across membrane.

Question 26

How are neurons polarized?

Answer 26

They are electrical polarized more negative on the inside and positive outside, this is due to uneven ion distribution =RMP.

Question 27

Step by step explain membrane potential. Hint: 4 steps (4a-c)

Answer 27

1. RMP = -70mV
2. Ion distribution across membrane (more + ions outside, more - ions inside)
3. Role of Na+/K+ pump is to keep Na+ outside and K+ inside.
4. Ion channels

A. Voltage gated ion channels open when membrane voltage changes to reach threshold.

B. Chemical gated ion channels open when certain chemical binds. E.g acetylcholine

C. Mechanical gated ion channels open due to distortion.

Question 28

Define ion channels.

Answer 28

Are pore or “gates” to regulate ion flow inside and outside of cells.

Question 29

What are action potentials?

Answer 29

They are nerve impulses.

Question 30

Name the two events of AP.

Answer 30

Summation and Threshold potential (-55mV)

Question 31

What is summation?

Answer 31

When all incoming signals from dendrites are added up at the cell body membrane.

Question 32

What is threshold potential?

Answer 32

When lots of excitatory signals arrive at cell from dendrites.

Question 33

The AP acts on an___________.Has to reach______ before it will fire, and then it will fire completely.

Answer 33

All or none principle, threshold

Question 34

The process of AP occurs repeatedly about (100/200) many times per (second/minute).

Answer 34

100, second

Question 35

What is the chemical signaling mechanism?

Answer 35

Is an international, involved with synapses for neurotransmitters.