Chapt. 3

Question 1

Tell me about a reflex arc.

Answer 1

these have a different speed of conduction compared to measure action potentials

Question 2

Which is faster? The speed of conduction along an axon or the speed of conduction through a reflex arc?

Answer 2

The speed of conduction along an axon. It occurs at 40 m/s while a reflex’s speed is about 15 m/s.

Question 3

What is temporal summation?

Answer 3

it explains that repeated stimuli can have a cumulative effect and can produce a nerve impulse when a single stimuli is too weak

Question 4

What is a presynaptic neuron?

Answer 4

a neuron that delivers the synaptic transmission

Question 5

What is postsynaptic neuron?

Answer 5

a neuron that receives the message

Question 6

What is Excitatory Postsynaptic Potential (EPSP)?

Answer 6

graded potential that decays over time and space

Question 7

What fact led to the idea of Spatial Summation?

Answer 7

the fact that several stimuli produce reflexes where a single stimuli cannot

Question 8

What is Spatial Summation?

Answer 8

synaptic input from several locations can have a cumulative effect and trigger a nerve impulse (it is also critical to brain functioning)

Question 9

What is Inhibitory Postsynaptic Potential (IPSP)?

Answer 9

it occurs when synpatic input selectively opens the gates for positively charged potassium ions to leave the cell or negatively charged chloride ions to enter the cells (serves as an active “brake” that suppresses excitation)

Question 10

Explain Spontaneous Firing Rate.

Answer 10

it is the periodic production of action potentials despite synaptic input

Question 11

What do EPSPs do to the number of action potentials occurring during the spontaneous firing rate?

Answer 11

increase it above the spontaneous firing rate

Question 12

What do IPSPs do to the number of action potentials occurring during the spontaneous firing rate?

Answer 12

decrease it below the spontaneous firing rate

Question 13

Communication across the synapse occurs via…?

Answer 13

chemical means

Question 14

What are neurotransmitters?

Answer 14

chemicals that travel across the synapse and allow communication between neurons

Question 15

What are the major categories of neurotransmitters?

Answer 15

• amino acids
• monoamines
• acetylcholine
• neuropeptides
• purines
• gases

Question 16

What are reflexes?

Answer 16

autonomic muscular responses to stimuli

Question 17

What are catecholimines?

Answer 17

these contain a catechol group and an amine group. (epinephrine, norepinephrine, dopamine)

Question 18

What are the vesicles?

Answer 18

tiny spherical packets located in the presynaptic terminal where neurotransmitters are held for release

Question 19

What is exocytosis?

Answer 19

the excretion of the neurotransmitter from the presynaptic terminal into the synaptic cleft (triggered by an arriving action potential)

Question 20

How long does transmission across the synaptic cleft by a neurotransmitter take?

Answer 20

fewer than 0.01 microseconds

Question 21

How many neurotransmitters do neurons release?

Answer 21

at least 2 different ones

Question 22

What does the effect a neurotransmitter has depend on?

Answer 22

its receptor on the postsynaptic cell

Question 23

Define the Ionotropic Effect.

Answer 23

This effect happens or takes place when a neurotransmitter attaches itself to receptors and immediately opens ion channels

Question 24

What types of channels are controlled by a neurotransmitter?

Answer 24

transmitter-gated or ligand-gated channels

Question 25

When do metabotropic effects occur?

Answer 25

when neurotransmitters attach to a receptor and initiate a sequence of slower and longer lasting metabolic reactions

Question 26

What does the "General Rule" state about neurons?

Answer 26

a neuron delivers neuropeptides that diffuse to receptors throughout a wide area, but delivers other transmitters in small amounts directly adjacent to their receptors

Question 27

What is the Exception to the "General Rule"?

Answer 27

the neurogliaform cell which is a neuron shaped like a glia cell that releases huge amounts of GABA all at once

Question 28

Define a hormone.

Answer 28

a hormone is a chemical secreted by a gland or other cells that is transported to other organs by the blood where it alters activity

Question 29

What are the endocrine glands responsible for?

Answer 29

the production of hormones

Question 30

What do the transporters do?

Answer 30

they are special membrane proteins that facilitate reuptake

Question 31

In what two ways is negative feedback in the brain accomplished?

Answer 31

through autoreceptors and post synaptic neurons

Question 32

How do drugs work?

Answer 32

by mimicking our own neurochemistry

Question 33

An antagonist is a drug that...

Answer 33

BLOCKS a neurotransmitter

Question 34

An agonist is a drug that...

Answer 34

INCREASES a neurotransmitters EFFECTS

Question 35

What parts of the nucleus respond to pleasure and motivation?

Answer 35

small parts respond to pleasure, large parts respond to motivation

Question 36

Motivation is related to..

Answer 36

wanting

Question 37

Pleasure is related to..

Answer 37

liking

Question 38

In moderate amounts, alcohol is associated with what?

Answer 38

relaxation

Question 39

What is alcoholism (alcohol dependence)?

Answer 39

the habitual use of alcohol despite medical or social harm

Question 40

What can strongly influences alcoholism?

Answer 40

genetics

Question 41

Contributed factors to substance abuse include:

Answer 41

- tolerance develops - cravings in response to cues - brain reorganization

Question 42

What are some medications used to combat alcoholism?

Answer 42

- antabuse - revia (naloxone) - medications are mainly used to reduce cravings

Question 43

How does Antabuse work?

Answer 43

it works by antagonizing (blocking) effects of acetaldehyde dehydrogenase and if a person drinks with it it turns into poisonous substance acetaldehyde and causes sickness (this medication is only moderately effective)