Neural Conduction And Synaptic Transmission

Question 1

Ramon y Cajal established the ____ ____, which states that the brain is made of many small, discrete cells.

Answer 1

Neuron Doctrine

Question 2

There are almost ____ billion neurons in the human brain.

Answer 2

100

Question 3

Neurons have four important regions

Answer 3

Dendrites
Soma (Cell Body)
Axon
Axon Terminal

Question 4

Dendrites

Answer 4

Branching projections that collect information

Question 5

Soma (Cell Body):

Answer 5

Contains the nucleus and integrates information

Question 6

Axon:

Answer 6

Conducts the neural signal across a long distance

Question 7

Axon terminals:

Answer 7

Small swellings that release signals to affect other neurons

Question 8

Chemical signals, known as _____, cross small gaps, known as synapses.

Answer 8

neurotransmitters

Question 9

It is estimated that there are about ___ trillion synapses in the adult brain.

Answer 9

500

Question 10

A type of neuron that carry information to the brain.

Answer 10

Sensory neurons

Question 11

A type of neuron that carry information from the brain to the muscles.

Answer 11

Motor neurons

Question 12

A type of neuron that convey the signals around the nervous system.

Answer 12

Interneurons

Question 13

A type of neuron that have many dendrites.

Answer 13

Multipolar neurons

Question 14

A type of neuron that have one dendrite and one axon.

Answer 14

Bipolar neurons

Question 15

A type off neuron that have only one projection from the soma, which branches to form the axon and the dendrite

Answer 15

Monopolar neurons

Question 16

Glial Cells

Answer 16

• Speeding up the neuronal signaling
• Regulating extracellular chemicals
• Enabling neurons to modify their connections

Question 17

In the glial cells, _______ , in the central nervous system, and ________, in the peripheral nervous system, _______ around axons to speed up signals.

Answer 17

Oligodendrocytes
Schwann cells
wrap myelin

Question 18

Nodes of Ranvier

Answer 18

are small gaps in the myelin sheath.

Question 19

Astrocytes .

Answer 19

regulate extracellular chemicals and regulate local blood flow

Question 20

Microglia

Answer 20

provide immune system functions for the central nervous system.

Question 21

The synaptic cleft is the _____ to _____ space between the cells.

Answer 21

20- to 30-nm

Question 22

Monoamines

Answer 22

Serotonin
Epinephrine
Norepinephrine
Dopamine
Melatonin

Question 23

Amino acids

Answer 23

Glutamate
Gaba
Glycine
Aspartate

Question 24

Peptide Neurotransmitters

Answer 24

Cholecystokinin
Neuropeptide Y
Somatostatin

Question 25

Gases

Answer 25

Nitric Oxide
Carbon Monoxide

Question 26

Organic cation

Answer 26

Acetylcholine

Question 27

Receptors

Answer 27

Specialized proteins in the cell membrane

Question 28

Difference of Ionotropic receptors and Metabotropic receptors

Answer 28

Ionotropic receptors used ions to flow across the membrane which changes the charge of the cell membrane. It allows ions to move through a passage in the membrane. On the other hand, metabotropic receptors used proteins to relay information. It relays signals to proteins inside the cell.

Question 29

Way to remove the receptors

Answer 29

Degradation, the neurotransmitter is broken apart. Diffusion the neurotransmitter moves down the concentration gradient and out of the synapse. Reuptake the neurotransmitter is transported back into the original cell.

Question 30

The inside of the cell is more negative than the outside, about _____

Answer 30

-70 mV.

Question 31

Difference between Excitatory Postsynaptic Potential and Inhibitory Postsynaptic Potential

Answer 31

EPSP alter the membrane voltage, moving the voltage closer to 0. Occurs when positive ions flow through an ionotropic receptor into the cell, causing depolarization. IPSP move the voltage further from 0. occurs when positive ions flow out of the cell, or negative ions flow in.

Question 32

Explain the temporal and spatial summation

Answer 32

No summation occurs when EPSPs arrive with a delay between them; they, individually, cannot drive the membrane voltage to the threshold for a spike.

Temporal summation occurs when EPSPs arrive close in time and their contributions add up at the soma, leading to an action potential.

Spatial summation occurs when signals arrive on different branches of the dendrites, converging at the soma.

If an EPSP and an IPSP arrive at different locations at the same time, they will cancel each other’s effect at the soma.

Question 33

How an action potential travels

Answer 33

In neurons at rest, there are more Na+ ions outside the cell and more K+ ions inside the cell.

At threshold, voltage-gated Na+ channels open, allowing Na+ ions to flow into the cell, down the chemical concentration and electrical gradients.

Voltage-gated K+ channels open, allowing K+ ions to flow out of the cell.

The current formed by the Na+ ions flows down the neuron, depolarizing the next part of the neuron.

There is a refractory period after the action potential, when the voltage-gated Na+ ion channels are less likely to open

Question 34

Are neurons integrators or coincidence detectors?

Answer 34

Because neurons receive thousands of inputs, they may be better thought of as coincidence detectors. The cell body of the postsynaptic cell is unable to determine which presynaptic neuron sent which signal—instead, a postsynaptic spike will only signal the coincidence of many excitatory inputs arriving simultaneously.