exam 1

During the muscle spindle reflex, information flows in what order?

Muscle spindle → sensory neuron → muscle fiber → motor neuron

Sensory neuron → muscle fiber → motor neuron → muscle spindle

Muscle fiber → motor neuron → sensory neuron → muscle spindle

Muscle spindle → sensory neuron → motor neuron → muscle fiber

Muscle spindle → sensory neuron → motor neuron → muscle fiber

What type of neuron transmits impulses through the PNS to the CNS?

Sensory neuron

Motor neuron

Interneuron

Sensory neuron

What is the primary area for receiving early-stage visual information?

Occipital Lobe

Parietal Lobe

Temporal Lobe

Frontal Lobe

Occipital Lobe

A 41 - year old male presents to the ER with paralysis involving the left arm and hand, Imaging shows a small lesion in his cerebral cortex. The lesion is located in which lobe of the brain?

Occipital Lobe

Parietal Lobe

Temporal Lobe

Frontal Lobe

Frontal Lobe

The principal region of the neuron for receiving information is the:

Dendrite

Axon

Myelin

Nucleus

Dendrite

Which region of the neuron is typically myelinated?

Soma

Dendrites

Dendritic spines

Axon

Axon

In a typical synapse, the presynaptic side is the ____ and the postsynaptic side is the ____.

Dendritic spine; cell body

Axon terminal; dendritic spin

Axon terminal; cell body

Axon hillock; axon terminal

Axon hillock; dendritic spine

Axon terminal; dendritic spin

Why is the resting potential in a neuron typically around -70 mV instead of being equal to the equilibrium potential of K+ (~- 90 mV)?

There are not enough open K+ channels at rest

The resting cell membrane has some permeability to Na+

K+ is sequestered inside the cell to reduce the actual intracellular K+ concentration

Intracellular Na+ blocks some of the K+ channels

The resting cell membrane has some permeability to Na+

What would happen to the typical neuronal membrane resting potential if the extracellular concentration of K+ was increased?

The resting potential would not change.

The resting potential would become more negative.

The resting potential would become more positive.

The resting potential would become more positive.

A neuron codes for the intensity of a stimulus by:

Increasing or decreasing the amplitude the amplitude of the action potential

Increasing or decreasing the duration of the action potential

Increasing or decreasing the frequency of action potentials

Decreasing the rate of potassium influx

Both A and B

Increasing or decreasing the frequency of action potentials

Dopaminergic neurons in the nucleus accumbens contain nicotinic receptors on their axon terminals. These receptors are permeable to Ca^2+. What effect will smoking cigarettes have on these dopaminergic synapses?

Decreased stimulation of postsynaptic dopamine receptors

Decreased release of dopamine

Prolong presynaptic action potential

Increased release of dopamine

Increased influx of Ca^2 into dopaminergic axon terminal.

Increased release of dopamine

True or False: The definition of a drug is always the same, regardless of context.

False

True or False: A drug is an exogenous substance.

True

A psychoactive drug is a drug that

blocks spinal nerves

blocks the cranial nerves

affects thinking, mood, or behavior

both A and B

affects thinking, mood, or behavior

Drug tolerance refers to:

the diminished effect with repeated use

the increased effect with repeated use

how safe the drug is

the increased number of side effects with repeated use

the diminished effect with repeated use

Which of the following scenarios represents an example of instrumental drug use?

drinking alcohol at a party to have fun

taking morephine to relieve back pain after surgery

using marijuana and watching a funny movie

taking a valium to increase the effects of alcohol

taking morephine to relieve back pain after surgery

True or False: Humans have 12 pairs of cranial nerves that all serve motor functions

False

hippocampus

involved in memory formation

limbic system

group of structures involved in the regulation of emotions and emotional interpretation of environmental stimuli

basal ganglia

group of structures that control smooth, voluntary movements

cerebellum

important for motor planning and learning

medulla

coordinates basic life support systems including respiratory rhythms

frontal lobe

planning and signaling movements

parietal lobe

somatosensory (touch and pain)

temporal lobe

hearing, language

occipital lobe

early stage vision

The nervous system is made up of cells called

axons

dendrites

neurons

nuclei

neurons

True or False: Understanding the properties of individual neurons is essential to understanding the relationship between brain and behavior.

True

Myelin is made from

dendrites

axons

glial cells

blood cells

voltage-gated ion channels

glial cells

True or False: Electrical signals within a single neuron typical flow in more than one direction.

False

Which part of the neuron typically serves as the input region?

dendrites

soma

axon hillock

axon

axon terminal

dendrites

True or False: The structure of a neuron is unrelated to its function.

False

A membrane potential is the difference in electrical charge between

ganglia and nerves

synapses and cell bodies

the inside and outside of a cell

nuclei and tracts

ions and channels

the inside and outside of a cell

Potassium ions have a ________ charge and are in excess ______ the cell; sodium ions have a ________ charge and are in excess _______ the cell.

negative, inside, positive, outside

negative, inside, negative, outside

positive, inside, positive, outside

positive, outside, negative, inside

positive, inside, positive, outside

Which of the following is a passive process that acts to distribute ions evenly in neural tissue?

diffusion

electrostatic pressure

sodium-potassium pumps

all of the above

A and B only

A and B only

Na+ ions are continually forced into neurons by

their high internal concentration

their high external concentration

the negative resting potential

both B and C

both A and C

both B and C

At resting potential, potassium is

driven out of the cell by electrostatic forces

driven into the cell by electrostatic forces

driven into the cell by its concentration gradient

driven out of the cell by its concentration gradient

both B and D

both B and D

What would happen to the typical neuronal membrane resting potential if the extracellular concentration of sodium was increased?

the resting potential would not change

the resting potential would become more negative

the resting potential would become more positive

the resting potential would first become more negative and the quickly go back to normal

the resting potential would not change

The brief period of time immediately after the initiation of an action potential when it is absolutely impossible to initiate another one in the same neuron is called the

threshold of excitation

threshold of inhibition

absolute refractory period

relative refractory period

absolute refractory period

Action potentials do not go backwards because

inertia

removal of the Na+/K+ pump

myelination

voltage-gated K+ channels are closed

Na+ channels become inactivated

Na+ channels become unactivated

What action would depolarize a neuron?

reducing how much calcium can get into the cell

increasing how much chloride can get into the cell

decreasing how much sodium can get into the cell

increasing how much sodium can get into the cell

all of the above

increasing how much sodium can get into the cell

A drug that blocks the voltage-gated sodium channel in a neuron's membrane will

block the action potential

decrease the threshold of excitation

cause repeated action potentials

prolong the refractory periods

have no effect on neurotransmission

block the action potential

Which action would hyperpolarize a neuron?

allowing more K+ to leave the cell

increasing how much chloride can get into the cell

increasing how much sodium can enter the cell

all of the above

A and B only

A and B only

An action potential typically begins at the

dendritic spine

place where the dendrite meets the cell body

axon hillock

axon terminal

axon hillock

The all-or-nothing property of the action potential refers to

the action potential's strength increases with the strength of the stimulus

the action potential either occurs completely or not at all, regardless of stimulus strength above the threshold

the action potential can vary in size depending on the type of neuron

the action potential decreases in amplitude as it travels down the axon

the action potential either occurs completely or not at all, regardless of stimulus strength above the threshold

The downstroke (falling phase) of action potential is due to:

the opening of voltage-gated sodium (Na+) channels

the closing of potassium (K+) leak channels

the opening of voltage-gated potassium (K+) channels and the efflux of potassium ions

the opening of voltage-gated potassium (K+) channels and the influx of potassium ions

the opening of voltage-gated potassium (K+) channels and the efflux of potassium ions

Neurotransmitters are often stored in

vesicles in the presynaptic neuron

nodes of ranvier

the synaptic cleft

vesicles in the postsynaptic neuron

vesicles in the presynaptic neuron

Entry of ____ into the axon terminal allows vesicles to fuse with the presynaptic membrane and release _________________ into the synapse.

Cl-, receptors

Cl-, neurotransmitters

K+, neurotransmitters

Ca2+, neurotransmitters

Ca2_, receptors

Ca2+, neurotransmitters

What makes EPSPs excitatory?

EPSPs increase the probability of firing because they hyperpolarize the postsynaptic neuron.

EPSPs increase the probability of firing because they depolarize the postsynaptic membrane.

EPSPs decrease the probability of firing because they depolarize the postsynaptic membrane.

EPSPs decrease the probability of firing because they hyperpolarize the postsynaptic membrane.

Because they occur only in excitatory neurons.

EPSPs increase the probability of firing because they depolarize the postsynaptic membrane.

EPSPs are

graded responses

postsynaptic responses

transmitted decrementally

depolarizations

all of the above

all of the above

After release, neurotransmitters are removed from the synapse by

Reuptake

Enzymatic degradation

G proteins

All of the above

A and B only

A and B only

If a neurotransmitter binds to a ligand-gated ion channel and Na+ channels are opened, what type of postsynaptic response will be recorded?

no change in postsynaptic membrane voltage

EPSP

IPSP

action potential

EPSP

Which of the following is False regarding metabotropic receptors?

they are coupled to G proteins

they directly affect ion channels after NT binding

their effects are slower than ionotropic receptors

all of the above are true

they directly affect ion channels after NT binding

True or False: Every time a neuron receives an excitatory input, it fires an action potential.

False