Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PSYC 302 > Chapter 2 - Quiz 1 > Flashcards

Chapter 2 - Quiz 1 Flashcards

1
Q

2,1 The concept of the Synapse

What did Charles Sherrington discover in 1906? Define it. (2)

A

-synapses
-a specialized gap as a point of communication between two neurons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

2.1 -1 Properties of Synapses

Define reflexes. Define reflex arc. (2)

A

-automatic muscular responses to stimuli
-a circuit from sensory neuron to muscle response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

2.1 -1 Properties of Synapses

Why was Sherrington curious about neurons? How did Sherrington discover synapses? (2)

A

-the prevailing belief before was that nerve impulses travelled continuously along nerve fibers, but these couldn’t t explain the delay between stimuli and response like a reflex
-tested reflexes in a dog who was strapped into a harness above the ground by pinching its foot. Here he noticed a delay and wanted to know why.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

2.1 -1 Properties of Synapses

What three properties did Sherrington find that suggest a junction exists between neurons? (3)

A

-reflexes are slower than action potentials along a single axon
-several weak stimuli presented at nearby places or times produce a stronger reflex than one stimulus alone does
-when one set of muscles becomes excited a different set becomes relaxed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

2.1 -1b Temporal Summation

What did Sherrington refer to as temporal summation? Why does it happen and what does it lead to? What is its purpose? (4)

A

-Combining signals that arrive at a neuron in a short time.
-Happens when a neuron gets signals in rapid succession from the same source.
-Leads to a stronger or longer response from the receiving neuron.
-Helps the brain process information quickly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

2.1 -1b Temporal Summation

What is an example of temporal summation? Describe what the temporal summation does for the person. Why is it useful? (4)

A

-You accidentally touch a hot stove with your hand causing pain receptors in the skin to send signals to the brain to alert about the danger.
-this causes rapid signals
-The combined effect of these signals results in a stronger and prolonged perception of pain.
-this prompts you to quickly withdraw your hand to prevent further injury.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

2.1 -1b Temporal Summation

What is a graded depolarization known as? Which gates open in the cell? If the depolarization does not cause the cell to reach its threshold, what happens? (3)

A

-excitatory postsynaptic potential (EPSP)
-sodium gates open
-the depolarization decays quickly

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

2.1 -1b Temporal Summation

What are the two types of electrical signals in neurons?

A

-action potentials and graded potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

2.1 -1b Temporal Summation

What two options can graded potentials be?

A

-excitatory/depolarizing or inhibitory/hyperpolarizing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

2.1 -1b Temporal Summation

What are the characteristics of action potentials? (3)

A

-always of the same magnitude and duration
-involve rapid depolarization followed by repolarization and often hyperpolarization
-propagate over long distances without losing strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

2.1 -1b Temporal Summation

Describe the function of the action potential (2)

A

-used for long-distance communication
-transmit info from one part of neuron to another and from one neuron to another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

2.1 -1b Temporal Summation

What are the characteristics of a graded potential? (3)

A

-magnitude and duration depend on the strength and duration of the stimulus
-do not propagate over long distances and tend to weaken over time and space
-can be either depolarizing (excitatory) or hyperpolarizing (inhibitory)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

2.1 -1b Temporal Summation

What are the functions of graded potentials? (3)

A

-serve as short-distance signals, primarily occurring in the dendrites and cell body of neurons
-sums up inputs from multiple sources
-can summate spatially (across different synapses) and temporally (over time) to influence the generation of action potentials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

2.1 -1c Spatial Summation

What did Sherrington also discover when he would pinch two points in different areas simultaneously? What concept did this showcase? (2)

A

-neither pinch alone produced a reflex but together they did
-concept of spatial summation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

2.1 -1c Spatial Summation

Do temporal summation and spatial summation work together or independently?

A

-Temporal and spatial summation often work together. Imagine waves hitting different parts of the shore at different times and strengths.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

2.1 -1d Inhibitory Synapses

Describe the experiment in which Sherington discovered inhibitory responses?

A

-Sherrington’s idea: Pinching the foot sends a message to a spinal cord neuron. This neuron excites muscles in the pinched leg and the other legs’ opposite muscles, while also calming muscles in the pinched leg and the other legs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

2.1 -1d Inhibitory Synapses

What is the temporary hyperpolarization of a membrane called? What does it cause to happen in the cell? (2)

A

-inhibitory postsynaptic potential (IPSP)
-synaptic input selectively opens the gates for potassium ions to leave the cell or for chloride ions to enter the cell

-IPSP makes the cell’s charge more negative temporarily, lowering the chance of an action potential.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

2.1 -1d Inhibitory Synapse

Can an inhibitory message flow along an axon? Why or why not? (2)

A

-no
-No, inhibitory messages cannot flow along an axon. Axons transmit signals away from the cell body. Inhibitory messages are conveyed across synapses and make it less likely for an action potential to occur in the postsynaptic neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

2.1 -2 Relationship among EPSP, IPSP and Action potentials

What is a spontaneous firing rate? What increases it and what decreases it? (2)

A

-a periodic production of action potentials even without synaptic input
-EPSP increase this and IPSP decrease it

-reflects the baseline level of activity of a neuron in the absence of external stimulation
-a neurons spontaneous firing rate could be 10 action potentials per second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

2.2 -1 The Discovery of Chemical Transmission at Synapses

What was Loewi’s evidence that neurotransmission depends on the release of chemicals?

A

-he stimulated nerves to alter heart rates in frogs, collected fluid from around the hearts affected by these stimuli, transferred this fluid to other frogs’ hearts, and observed corresponding changes in heart rate, demonstrating that nerve stimulation released chemicals that could influence heart function.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

2.2 -2 The Sequence of Chemical Events at a Synapse

Describe the steps of chemical events at a synapse (7)

A

-neuron makes neurotransmitters (small chemicals are made in axon terminal and neuropeptides in the cell body)
-action potential travels down the axon enabling calcium to enter the cell at the presynaptic terminal
-calcium releases neurotransmitters from terminals and into the synaptic cleft
-these neurotransmitters diffuse across the space, attach to receptors and change the activity of the postsynaptic neuron
-NT separate from their receptors
-NT may be taken back into presynaptic neuron for recycling or diffuse away
-some postsynaptic cells send reverse messages to control further release of NT by presynaptic cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

2.2 -2a Types of Neurotransmitters

What are the 6 groups of NT?

A

-amino acids, A modified amino acids, monoamines, neuropeptides, purines, gases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

2.2 -2a Types of Neurotransmitters

What is the oddest NT? What does it do? (2)

A

-nitric oxide
-increases blood flow to area

-also isn’t stored in a vessicle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

2.2 -2b Synthesis of Transmitters

What are catecholamines? Which NT? (2)

A

-contain a catechol group and an amine group
-epinephrine, norepinephrine, dopamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

2.2 -2c Storage of Transmitters

What is MAO? What is its purpose? (2)

A

-enzyme that converts catecholamines and serotonin into synaptically inactive chemicals called MAOIs
-breaks these NT into inactive forms, preventing their accumulation into harmful amounts

26
Q

2.2 -2d Release and Diffusion of Transmitters

Does an action potential itself release the NT at the end of an axon?

A

-no, depolarization opens voltage-dependent calcium gates in presynaptic terminal which causes exocytosis

-exocytosis is a release of neurotransmitters from the presynaptic neuron into the synaptic cleft

27
Q

2.2 -2e Activating Receptors of the Postsynaptic cell

What are the two effects that can happen when a NT attaches to its receptor? (2)

A

-receptor may open a channel (ionotropic effect)
-receptor may produce a slower but longer effect (metabotropic effect)

28
Q

2.2 -2f Ionotropic Effects

What is an ionotropic effect?

A

-on/off switch where input either produces excitation or inhibition

-synaptic effects that depend on the rapid opening of some kind of gate in the membrane
-like a bag that twists open

29
Q

2.2 -2f Ionotropic Effects

The channels controlled by a NT (Ionotropic), as compared to the voltage-gated channels sodium and potassium channels are what? Define this term. (2)

A

-transmitter-gated or ligand-gated
Transmitter-gated/ligand-gated: ion channel that opens temporarily when a neurotransmitter binds to it

30
Q

2.2 -2f Ionotropic Effects

Which NT do most ionotropic effects depend on for excitatory and inhibitory ionotropic synapses?

A

-glutamate (excitatory) or GABA (inhibitory)

-glycine as inhibitory and acetylcholine as excitatory as well

31
Q

2.2 -2g Metabotropic Effects and Second Messenger Systems

Define metabotropic effects. Which NT do they use? (2)

A

-a sequence of metabolic reactions that produce slow and long-lasting effects at a synapse
-many including dopamine, norepinephrine, and serotonin (sometimes glutamate and GABA too)

32
Q

2.2 -2g Metabotropic Effects and Second Messenger Systems

What is a G protein?

A

-protein coupled with guanosine triphosphate (GTP)

33
Q

2.2 -2g Metabotropic Effects and Second Messenger Systems

What is the result of the metabotropic effect which bends the receptor protein detacthing the G protein?

A

-the G protein takes its energy elsewhere in the cell and results in an increased concentration of a second messenger

34
Q

2.2 -2g Metabotropic Effects and Second Messenger Systems

What is the first and second messenger? (2)

A

-first messenger is signaling molecule like NT
-second messenger relays the signal of the first messenger and communicates to areas within the cell

-the ability of metabotropic synapses to influence much or all activity of the cell over a longer period of time seperates this synapse from ionotropic

35
Q

2.2 -2g Metabotropic Effects and Second Messenger Systems

Which behaviors or perceptions are ionotropic and metabotropic effects responsible for? (2)

A

-ionotropic is responsible for vision and hearing where the brain needs quick info
-metabotropic is responsible for taste, smell and pain as these are more enduring effects

36
Q

2.2 -2h Neuropeptides

What do researchers often refer to neuropeptides as? Why? (2)

A

-neuromodulators
-because they have properties that set them apart from other transmitters

37
Q

2.2 -2h Neuropeptides

What are the differences between NT and neuropeptides? Start with neuropeptides. Synthesized? Released from and by? Effects what and where and for how long? (6)

A

-synthesized in cell body
-released mostly from dendrites and sometimes cell body
-released by repeated depolarization
-effects neighboring cells by causing them to release neuropeptides too
-diffuses to wide area
-duration is minutes

38
Q

2.2 -2h Neuropeptides

What are the differences between NT and neuropeptides? DO NT. Synthesized? Released from and by? Effects what and where and for how long?

A

-synthesized in presynaptic terminal
-released in axon terminal
-released by single action potential
-has no effect on neighbors
-the effect spreads mostly to receptors on the postsynaptic cell
-takes milliseconds to seconds

39
Q

2.2 -2j Drugs that Act by Binding to Receptors

Define hallucinogenic drugs. Give an example

A

-drugs that distort perception
-LSD chemically resembles serotonin

40
Q

2.2 -2j Drugs that Act by Binding to Receptors

How does nicotine work with NT?

A

-stimulates a family of acetylcholine receptors known as nicotinic receptors, which are abundant on neurons that release dopamine

41
Q

2.2 -2j Drugs that Act by Binding to Receptors

What do opiate drugs mimic?

A

-they bind to receptors for endorphins and relieve pain

42
Q

2.2 -2k Inactivation and Reuptake of Neurotransmitters

Are neuropeptides inactivated?

A

-no, they diffuse away

43
Q

2.2 -2k Inactivation and Reuptake of Neurotransmitters

After acetylcholine activates a receptor, which enzyme breaks it down

A

-acetylcholinesterase breaks it into two fragments, acetate and choline

-it then recycles it, but this takes time

44
Q

2.2 -2k Inactivation and Reuptake of Neurotransmitters

Why might a transmission be slowed after a rapid series of action potentials?

A

-since the presynaptic neuron does not reabsorb every molecule it makes, the NT would be depleted

45
Q

2.2 -2k Inactivation and Reuptake of Neurotransmitters

What happens to serotonin and catecholamine molecules after they stimulate a postsynaptic receptor? Define reuptake. Define COMT. (3)

A

-they do not break down at postsynaptic membrane and are either reuptake or broken down by an enzyme called COMT
-Reuptake: reabsorption of a NT at the presynaptic terminal through transporter proteins
-COMT: enzyme that breaks down excess dopamine

46
Q

2.2 -2k Inactivation and Reuptake of Neurotransmitters

What are transporters?

A

-special membrane proteins that reuptake NT

47
Q

2.2 -2k Inactivation and Reuptake of Neurotransmitters

How do amphetamine and cocaine influence synapses?

A

-They block reuptake of released dopamine, serotonin, and norepinephrine.

48
Q

2.2 -2k Inactivation and Reuptake of Neurotransmitters

What is methylphenidate?

A

-ritalin for ADHD

-similar properties for cocaine

49
Q

2.2 -2I Negative Feedback from the Postsynaptic Cell

What are autoreceptors? What do they provide? (2)

A

-receptors on a presynaptic neuron that respond to NT by inhibiting further making and releasing of it
-they provide negative feedback

50
Q

2.2 -2I Negative Feedback from the Postsynaptic Cell

What is a way that postsynaptic neurons provide negative feedback? What are examples of reverse transmitters? (2)

A

-they release chemicals that travel back to presynaptic terminal and inhibit further release of NT
-examples include nitric oxide, hydrogen ions, anandamide and 2-AG

51
Q

2.2 -2I Negative Feedback from the Postsynaptic Cell

What do cannabinoids bind to? (2)

A

-anandamide or 2-AG receptors on presynaptic neurons telling it that the cell got its message so stop sending it
-decreasing action potentials in general

52
Q

2.2 -2m Electrical Synapses

What is a gap junction?

A

-when at an electrical synapse the membrane of one neuron comes into direct contact with the membrane of another neuron

53
Q

2.2 -2m Electrical Synapses

How does electrical synapse work? (3)

A

-fairly large pores of the membrane of one neuron line up with other pores in membrane
-these pores are large enough that sodium and other ions pass freely (they remain open constantly)
-the two neurons essentially act as one

54
Q

2.2 -3 Hormones

Define a hormone

A

-chemical secreted by cells in one part of the body and carried by the blood to influence other cells

55
Q

2.2 -3 Hormones

What is the difference between a NT and a hormone and a neuropeptide? (3)

A

-NT is like a telephone signal, it conveys a message from the sender to the intended receiver
-hormones function more like radio station, they convey a message to any receiver tuned to the right station
-neuropeptides are intermediate

56
Q

2.2 -3 Hormones

What are two important types of hormones that activate a second messenger within the cell?

A

-protein and peptide hormones

-proteins are longer chains of amino acids and peptides are shorter chains
-they act like a first messenger

57
Q

2.2 -3 Hormones

What is the posterior pituitary gland composed of?

A

-neural tissue

58
Q

2.2 -3 Hormones

What is the anterior pituitary gland composed of?

A

-glandular tissue

59
Q

2.2 -3 Hormones

What brain structure produces vasopressin and oxytocin?

A

-the hypothalamus

60
Q

2.2 -3 Hormones

Define releasing hormones

A

-hormone released by the hypothalamus that flows to the anterior pituitary

PSYC 302 (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions