CHapter 2

Question 1

Central Nervous System

Answer 1

the brain and spinal cord

Question 2

Peripheral Nervous System

Answer 2

the nerve tissue located outside of the brain and spinal cord

Question 3

Glial Cells

Answer 3

• provide physical support
• control nutrient control
• involved phagocytosis

Question 4

Schwann Cell

Answer 4

-myelin sheath in the peripheral nervous system

Question 5

Oligodendrocyte

Answer 5

-myelin sheath in the central nervous system

Question 6

Microglia

Answer 6

• phagocytosis

- act like the immune system

Question 7

Astrocyte

Answer 7

• creates the blood brain barrier

- takes things from the blood vessels and passes them onto the nutrients

Question 8

Ramni Calal

Answer 8

-thought that there were synapses

Question 9

Golgi stain

Answer 9

• first stain that showed the whole neuron

- thought that neurons were connected

Question 10

Why do neurons have different shapes?

Answer 10

-different shapes for different functions
-some neurons bring information into the brain
some neurons send information out of the brain or to other parts of the brain

Question 11

Neuronal signaling overview

Answer 11

• the presynaptic neuron gives off a chemical signal to the postsynaptic neuron that gets turned into an electrical signal
• that electrical signal gets turned into another electrical signal and shoots down the axon

Question 12

Membrane potential/Resting membrane potential

Answer 12

• -70 mV means that the inside is more negative than the outside
• resting membrane potential is usually about -70 mV

Question 13

Where do the electrical and concentration gradients push potassium (K)?

Answer 13

• the electrical gradient pushes potassium into the cell
• the concentration gradient pushes potassium out of the cell
• these forces balance each other out

Question 14

Where do the electrical and concentration gradients pusH sodium (NA)?

Answer 14

• the electrical gradient pushes sodium into the cell

- the concentration gradient pushes sodium into the cell as well

Question 15

What does the sodium-potassium pump do?

Answer 15

• pushes potassium into the cell

- pushes sodium out of the cell

Question 16

What factors affect membrane potential?

Answer 16

• concentration gradient

- electrical gradient

Question 17

Ion channels + properties

Answer 17

• passive transport
• PROPERTIES of Ion Channels
  1. they are gated (you can open and closed them
  2. this is how neurons send electrical signals and change membrane potential
  3. they can be selective

Question 18

Voltage Gated Na+ Channels

Answer 18

• opens when senses depolarization
• fast opening
• quickly inactivates

Question 19

Voltage Gated K+ Channels

Answer 19

• opens when senses depolarization
• delayed opening
• stays open until cell repolarizes

Question 20

How are Voltage Gated Ion CHannels opened?

Answer 20

Voltage = a change in membrane potential opens them

Question 21

Hodgkin-Huxley Cycle

Answer 21

-happens where the axon is connected to the soma
-synaptic potential or receptor potential
1. membrane depolarizes
2. voltage-gated Na+ channels open
3. Na+ flows into neuron
back to 1.

Question 22

What is the Action Potential

Answer 22

• the action potential is the electrical signal that travels down the axon
• depolarization threshold/threshold of excitation must be reached
• all or none

Question 23

Myelin Sheath and Transport

Answer 23

• the myelin sheath allow for a tradeoff between passive and active transport
• when you have passive transmission of an axon potential the signal is not as strong
• when you have active transmission of an axon potential, you put the channels all along the axon and it takes time to build up

Question 24

Saltatory Conduction

Answer 24

-when a signal travels under the myelin it is passive
when a signal travels at the nodes of Ranvier, there are concentrations of voltage gated channels and it is actively transported
-the passive conduction allows for speed while the active conduction allows for strength
-in MS the myelin sheath is attacked and destroyed by the immune system which results in motor and nerve issues

Question 25

Overview of the Synapse

Answer 25

- convert action potential into a chemical signal that can cross the synaptic cleft - synaptic vesicles carry the neurotransmitters - when the action potential reaches the terminal calcium gated channels are activated there - calcium is a signaling neuron; stop or start

Question 26

Neurotransmitter Release & Receptor Binding

Answer 26

- the neurotransmitter floats across the synaptic cleft to the postsynaptic neuron and must be converted back into an electrical signal - the neurotransmitter binds to receptors on the postsynaptic neuron - the receptors open up ligand gated channels in the postsynaptic neuron - when the neurotransmitters bind to the ligand receptors gated ion channels are opened changing the POSTsynaptic potential

Question 27

Action Potentials Comparison

Answer 27

- caused by voltage gated ion channels - occurs in the - all or none - always have the same shape

Question 28

Postsynaptic Potential Comparison

Answer 28

- caused by ligand gated receptors - occur in the postsynaptic neuron - does not function on the all or none property; they can bed graded (s,m,l) - can hyperpolarize(IPSP) or depolarize(EPSP) - for the most part are passive

Question 29

Gap Junctions

Answer 29

- the hydrophilic pores allow the inside of one neuron to connect with the inside of another neuron - electrical synapse - transmission is faster - allows for synchronization of neurons