Neuroscience final exam

Which glial are responsible for maintaining the integrity of the extracellular fluid that surrounds neurons?

Astrocytes

What is the name of structure where the sensory nerves from the body enter the spinal cord?

Dorsal root ganglia

Which is another name for sensory neurons?

afferent neurons

Dendritic spines

Can change shape and number based on the strength of synaptic inputs.

Which membrane lies closest to the surface of the brain (farthest from the skull)?

Pia mater

Growth cones are associated with

regeneration in the peripheral nervous system.

Which neuroanatomical method provides an outline of entire neurons including the soma and all of the cell's processes?

Golgi stain

During a period of normal cell death, developing neurons are thought to compete for

neurotrophic factors.

During axonal transport, which of the following elements help move materials from the soma to the terminal?

motor proteins

Which of the following is a projection pathway linking the cerebral hemispheres?

Corpus callosum

Which of the following processes is involved in forming the final number of presynaptic and postsynaptic neurons during development?

Programmed cell death (apoptosis)

Which statement about dendrites is false?

Dendrites may be several meters in length in giraffes.

Which process occurs to only a limited extent after human birth?

Neurogenesis

Which of the two phenomena are the result of result somewhat similar neural processes?

Banding of the tectum in a 3-eyed frog and lamination in the Lateral Geniculate Nucleus of the thalamus

Which of the following classes of neurons can collect the most incoming information based on their morphology?

Multipolar

Which of the following neuroscience methods can be used to visualize proteins used by a neuron?

immunocytochemistry

If an axon is damaged at a distance from the cell body, the portion of the axon beyond the site of injury (towards the axon terminal) is lost through the process of

anterograde degeneration

Which of the following describes the chemoaffinity hypothesis as aplied to target selection and establishing topographic maps?

growing axons have receptors that seek specific chemical markers on their targets.

Multiple cell types, including neurons and glia, can arise from the same precursor cells. These precursor cells are also called which of the following?

multipotent stem cells

The major function of Schwann cells is the

myelination of peripheral nerve fibers

What structure produces CSF?

Choroid plexus

Migrating neurons are guided during very early development by

radial glia

The ventral roots of the spinal cord carry

motor information to muscles

The ability of the brain to be changed by environmental inputs throughout the life span is called

plasticity

What is retrograde axoplasmic transport?

Movement of material from axon terminal to soma

What is one of the major differences between MRI and CT?

MRI uses magnetic fields where CT scanning x-rays

What is the name of region where the axon begins?

axon hillock

Axons use chemoattractants and chemorepellants to guide their direction of movement by

following a gradient of concentration of those substances

In Multiple Sclerosis, myelin is lost, but there can be some recovery. If possible, which cells would be most likely involved in replacing lost myelin in the spinal cord?

Oligodendrocytes

Evidence shows that in _____ whose optic nerve has been damaged, _____

adult frogs; the retinal axons will grow back to their original positions on the tectum

Synaptic vesicles are found in the

synaptic boutons

The right hemisphere appears to be

important for processing emotional tone (prosody) of language

People whose facial muscles have become paralyzed tend to experience

emotions less intensely than they did before the paralysis

Brodmann constructed a map of the neocortex based on which of the following:

the differences in cytoarchitecture of the layers of cortex across the different areas of the brain

During the cell migration phase of cortical development, which layer of the cortex do the first cells migrate to and begin to differentiate?

Layer VI

The stage of Synaptic Rearrangement can be defined as a period in which

there is a loss of some synapses, and the development of others, to refine synaptic connections

What factors are thought to keep axons together that are growing along the same path?

Cell adhesion molecules

Certain growing axons are prevented from crossing the midline by

chemorepellents

Which of the following best describes spatial and temporal integration of synaptic inputs?

a process by which multiple synaptic potentials combine onto one postsynaptic neuron

A wider therapeutic window for a drug usually is associated with the drug

having a wider margin of safety

For most sensory pathways, the route from the periphery to the primary sensory cortex

passes through the thalamus

Somatosensory receptive fields on the lips are _____ compared to the receptive fields on the back

smaller

Balint's syndrome can occur with

bilateral damage to the parieto-occipital cortex

Typically, human patients with bilateral damage to the amygdala show a marked impairment in the ability to recognize expressions of _____ in other people

fear

The GABA receptor is usually inhibitory, and therefore typically causes a _____ channel to open

chloride

How are neurotransmitters cleared from the synaptic cleft?

enzymatic destruction and reuptake

How does myelin help increase conduction velocity?

it provides for more efficient propagation of the action potential

Which of the following best describes a gap junction between neurons?

it is an electrical synapse between the neurons

In the mammalian brain, a which of the following is almost always an excitatory neurotransmitter?

glutamate.

What is meant by the action potential threshold?

critical level of depolarization required to trigger an action potential

Which of the following events would cause a down-regulation of receptor sites?

a large number of agonists molecules are available to the receptors over a period of time

How does the sodium-potassium pump help maintain the resting membrane potential?

pumps K+ ions in and Na+ ions out

How does tetrodotoxin (TTX) affect channels to block action potentials?

TTX blocks Na+ channels

Why do action potentials travel only in one direction?

the membrane just behind the action potential is refractory due to inactivated Na+ channel

Which of the following are the major charge carriers involved in neural communication?

ions

An exogenous agonist

has the same effect on a channel as the native neurotransmitter

The dose at which a drug has a half-maximal response is termed the

ED50

Which factor other than the ionic concentration gradient determines the equilibrium potential for an ion?

the permeability of the membrane for the ion

In vesicular release of neurotransmitters, _____ molecules help dock the vesicle on the presynaptic membrane and prepare it for release

SNARE

A manufactured drug that interacts with a particular type of receptor in the brain is a(n) _____ ligand

exogenous

What is the term used to describe the mechanism for the regulation of K+ by astrocytes?

potassium spatial buffering

Whether a synapse is excitatory or inhibitory is determined by the

type of transmitter released by the presynaptic neuron and the receptor to which that transmitter binds on the postsynaptic neuron

If a drug is a GABA agonist, it would most likely cause

sedation

Sensory transduction is the process by which

energy is converted into a change in membrane potential

Postsynaptic potentials are a type of

graded potential

What role do voltage-gated K+ channels play in the action potential?

voltage-gated K+ channels restore negative membrane potential after the spike

What is the meaning of an ion's equilibrium potential?

electrical potential difference that exactly balances the ionic concentration gradient

Which of the following channels on the presynaptic axon terminal causes the release of synaptic vesicles?

voltage-gated calcium channels

At the peak of the action potential, the axonal membrane approaches the equilibrium potential for

Na+

Acetylcholine (ACh) is the main transmitter used at mammalian

neuromuscular junctions

G-proteins are able to amplify the message from a single receptor because they

activate second messenger proteins inside the cell

What is the absolute refractory period?

the time period of about 1 msec after an action potential before another one can be initiated

How long does an action potential last from the beginning of the rising phase to the end of the falling phase?

2 msec

When neurotransmitters bind to receptor sites that are directly on an ion channel, the response is _____

fast and ionotropic

The receptor potential produced by a Pacinian corpuscle in response to mechanical stimulation is

proportional to the stimulus intensity

How do action potentials differ from passively conducted electrical signals?

Action potentials are signals of fixed size and duration; passively conducted signals are not of fixed size or duration and diminish over distance

A drug that affects the function of a receptor without impeding the access of neurotransmitter molecules to their binding sites on the receptor is a

noncompetitive ligand

The endocrine system involves communication by release of chemical messengers which circulate through the _____

bloodstream

Lesions of the lateral hypothalamus (LH) in rats suggest that this is control center for _____

hunger

Which of the following neurotransmitters is not degraded by monoamine oxidase (ie, which is not a monoamine)?

acetylcholine

In general, the sympathetic nervous system _____, while the parasympathetic nervous system _____

arouses and mobilizes; maintains and conserves

L-dopa can reverse some of the symptoms of

Parkinson's disease

VentroMedial Hypothalamus (VMH)-lesioned rats show

an increase in appetite

Most of the energy available from a meal is consumed by

basal metabolism

The amount of leptin that is secreted is directly correlated to the

amount of adipose tissue a person has

The pathology of Huntington's disease is characterized by loss of neurons in some nuclei of the

basal ganglia

Which of the following provides the basis for proprioception?

sensory input from muscle spindles

Which of the following are the targets of the autonomic nervous system?

smooth muscle, cardiac muscle, and glands

What are central pattern generators in the motor system?

spinal circuits that give rise to rhythmic motor activity

Which of the following best describes neurohormones?

hormones that are released into the circulatory system by neurons

In terms of the distribution of motor neurons in the spinal cord,

the ventral horn is larger in the cervical segments than in the thoracic segments

In the somatotopic motor map of the primary motor cortex, the largest areas represented are those that

require the most precise control of movement

Why do mutant ob/ob mice become obese?

their adipose tissue does not produce leptin

The function of the anterior pituitary is

guided by the release of hypophysiotropic hormones

Partial (spastic) paralysis of one body side is a common result from damage to the

primary motor cortex

The SMA (supplemental motor area) is important for planning the _____ of motor movements

sequence

Which of the following is not a good example of a behavior that is controlled by a central pattern generator?

whistling

Which two hormones are released by the posterior lobe of the pituitary?

oxytocin and vasopressin

The occurrence of quick, irregular, dancing type movements is associated with

Huntington's disease

Individual motor neurons located in primary motor cortex seem to have a preference for responding to

a particular direction of limb movement