Neurons

Question 1

The nervous system is made of…

Answer 1

Neurons and Glia cells

Question 2

Neurons

Answer 2

specialized cells that can receive and send electrical and chemical signals

Question 3

Glia cells

Answer 3

Provide support functions to neurons

Question 4

Action Potentials

Answer 4

Electrical signals that travel along the axon of a neuron

Question 5

Neurotransmitters

Answer 5

Chemical signals that travel along the synapse and induce a change in membrane potential in the postsynaptic cell

Question 6

Dendrites

Answer 6

Little branches off the main body of the neuron, receive neurotransmitters from other neurons

Question 7

Synapses

Answer 7

Specialized junctions between neurons where they send and receive information

Question 8

Axon Hillock

Answer 8

Integrates multiple signals from other neurons. Serves as a junction between body and axon

Question 9

Axon

Answer 9

Tubelike structures that specialize in carrying signals to specialized ends are called axon terminals.

Question 10

Nodes of Ranvier

Answer 10

Gaps in myelin sheath where the action potentials recharge as it travels down the axon

Question 11

Types of Glia cells

Answer 11

MicroGlia, Astrocytes, Sattelite Glia, Oligodendrocytes, Schwann cells, and Ependymal cells

Question 12

Most Brain tumors are caused by…

Answer 12

Mutated glia cells

Question 13

Astrocytes

Answer 13

• Provide neurons with nutrients and other substances
• Regulate concentration of ions and chemicals in extracellular fluid
• Form a blood-brain barrier to block toxic substances from entering

Question 14

Sattelite Glia

Answer 14

Nutrients and structure support in Peripheral Nervous system

Question 15

Microglia

Answer 15

• Immune system of the central nervous system

* Scavenge and degrade dead cells and invading microorganisms

Question 16

Oligodendrocytes

Answer 16

• Form myelin sheaths along the axon

* One oligodendrocyte can provide a myelin sheath for multiple neurons

Question 17

Schwann Cell

Answer 17

• Form myelin sheath in the peripheral nervous system

* A single Schwann cell provides myelin for only one axon as the entire cell surrounds the axon

Question 18

Ependymal cells

Answer 18

• Line fluid-filled ventricles on the brain and central canal of the spinal cord
• Help circulate cerebrospinal fluid, which serves as a cushion for the brain

Question 19

Resting phase

Answer 19

Membrane potential in a neuron that is currently not transmitting a signal

Question 20

Action Potential

Answer 20

Brief depolarization along the axon

All or nothing

Question 21

Membrane potential at rest is around

Answer 21

-70 mV

Question 22

Resting membrane potential is established by…

Answer 22

Ion channels and pumps

Question 23

Sodium-Potassium ion pump

Answer 23

Pumps in 2 K+ ions and pumps out 3 Na+ ions. Uses ATP. important for maintaining electrogradient

Question 24

Potassium Leak channel

Answer 24

Allows potassium to leak outside of the cell

Question 25

Depolarization

Answer 25

Voltage-gated Na+ channels open quickly after threshold potential is reached. Sodium begins to rush into the axon, making it more positive (around 30mV)

Question 26

Repolarization

Answer 26

The Voltage-gated Na+ channel shuts and remains closed. Voltage-gated K+ channels open, K+ rushes out of the axon, causing the axon to become more negative, repolarizing

Question 27

Hyperpolarization

Answer 27

K+ continues to leave to the point where the axon below the resting potential

Question 28

Reset Resting Potential

Answer 28

Pumps and Ion channels work to reestablish resting potential for another Action potential to fire

Question 29

The action potential travels down the axon in...

Answer 29

waves

Question 30

Why don't Action Potentials go backward?

Answer 30

Voltage-gated ion channels like Na+ are shut and the hyperpolarization of previous action potential prevents backward movement of action potentials

Question 31

One node to another is called

Answer 31

Saltatory Conduction

Question 32

Once an action potential reaches the end of an Axon

Answer 32

The end of the axon depolarizes, this causes Voltage-gated Calcium channels to open. Calcium triggers a signaling cascade that causes synaptic vesicles to fuse with the pre-synaptic membrane, which releases neurotransmitters into the synaptic cleft.

Question 33

Excitatory Post-synaptic Potentials

Answer 33

Make neurons more likely to fire an action potential (depolarize)

Question 34

Inhibitory postsynaptic potentials

Answer 34

Make neurons less likely to fire an action potential (hyperpolarize)

Question 35

What gives the membrane of neurons their negative charge

Answer 35

The outflow of K+ ions results in the negative charge within the cell