physiol psych final exam

a researcher can determine how much of the human brain is used for even the simplest of tasks by

looking at brain activity in brain scans

which is a major advantage of studying human subjects?

• direct relevance to human disease

• better genetic manipulation

• greater control over variables

• fewer ethical regulations

direct relevance to human disease

which imaging method relies on X-ray technology?

CT

which term refers to the ability of an imaging method to distinguish two points in space?

spatial resolution

why does CLARITY make brain tissue transparent?

it removes lipids from tissue

in optogenetics, researchers use light sensitive ____ channels to stimulate or inhibit ____.

ion; neurons

in ____: in living, intact animals

vivo

in ____: in primary cell culture or slice culture

vitro

____ and ____ allow functional imaging of the brin

fMRI : PET

a major strength of EEG is its

temporal resolution

the adult human brain contains

80-90 billion neurons

the range of diameters of mammalian axons is

0.2-20 µm

dendrites are

the input zone of a nerve cell

although nerve cells typically have only one axon, an axon may divide into numerous axon

collaterals

synaptic vesicles are found in the

synaptic boutons

synaptic boutons are

swellings found at axon terminals

which type of cells give rise to brain tumors?

glial cells

which cranial nerve carries both motor and sensory information?

facial

fibers that carry information away from the brain are called ____, whereas fibers that carry information toward the brain are called ____.

efferents; afferents

the major function of schwann cells is the

myelination of peripheral nerve fibers

how many distinct layers are observed in the human neocortex

six

in the cerebral cortex, layers V and VI are unique in that they

contains many neurons with large cell bodies

the structures of the limbic system are critical in

emotion and learning

which structure contains the retricular formation

mesencephalon

parallel fibers are a feature of the

cerebellum

purkinje cells are located in the

cerebellum

the specialize vascular tissue that produces the cerebrospinal fluid is called the

choroid plexus

which arteries provide blood to the brain?

basilar artery, carotid artery, and vertebral artery

which statement about the blood-brain barrier is true?

• it is a property of neurons that prevents them from accidentally releasing their neurotransmitters into the blood circulation

• it is a property of the blood vessels of the brain that promotes the diffusion of nutrients into the tissue of the brain

• it is a property of the closely packed endothelial cells of the walls of brain capillaries that prevents large molecules from entering the brain

• it is a part of the immune system that involves the release of antibodies to protect the brain from infectious agents

it is a property of closely packed endothelial cells of the walls of brain capillaries that prevents large molecules from entering the brain

two important motor nuclei, the substantia nigra and the ____ nucleus, are contained within the ____.

red; midbrain

ion channels are made of

protein

in general, the action potential is first initiated at the

axon hillock

the sodium-potassium pump is responsible for

pushing three sodium ions out of the cell for every two potassium ions pumped in

at the K⁺ equilibrium potential, the electrostatic pressure pulling K⁺ ions into the neuron is balanced by the concentration gradient pushing them out; at this point, the

-65 mV

an afterpotential is

a brief hyperpolarization that follows an action potential (“undershoot”)

action potentials generally are not transmitted along dendrites because they have

few voltage-gated Na⁺ channels

when applying hyperpolarizing or depolarizing stimulus to the membrane of a neuron, the beginning and end of the neuron’s response become distorted. this is due to

capacitance of the membrane

myelin increases the speed of conduction because it

resists the flow of current across the membrane

the overall amplitude of the action potential is about

100 mV

whether a synapse is excitatory or inhibitory is determined by

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

____ receptors recognize the synaptic transmitter, but they do not themselves contain any ion channels

metabotropic

which process is not involved in chemical synaptic transmission?

• influx of calcium at the presynaptic membrane

• binding to autoreceptors

• electrical conduction across the synaptic cleft

• reuptake

electrical conduction across the synaptic cleft

most ACh receptors in the brain are

muscarinic

the lock-and-key analogy is used to describe the

action of transmitter molecules on receptor proteins

acetylcholine receptors are thought to be in the same family as GABA, glycine, and glutamate receptors because they

have a similar structure

the neurotransmitter acetylcholine acts on at least ____ different types of receptors

four

neurons process information by integrating (summing algebraically) the postsynaptic potentials through both ____ summation (summing potentials from different locations) and _____ summation (summing potentials across time)

spatial; temporal

during the action potential, the neuron cannot be excited by a second stimulus; it is ____. for a few milliseconds afterward, the hyperpolarized neuron is ____, requiring a stronger stimulation than usual in order to fire

absolutely refractory; relatively refractory

a ligand is a

molecule that binds to receptor proteins

the phenomenon of divergence is illustrated by the visual system, in which 1 million axons of the optic nerve communicate with ___ neurons in the cerebral cortex

over a billion

which of the following is not a specific criterion for classifying a substance as a neurotransmitter?

• ability of the substance to travel long distances between the site of origin and target area

• existence of speciufic receptors for the substance on the postsynaptic membrane

• existence of the substance in the presynaptic terminal

• release of the substance when nerve impulses reach the terminal ending

ability of the substance to travel long distances between the site of origin and target area

which substance is a monoamine neurotransmitter

dopamine

the NMDA receptor is a type of receptor for the neurotransmitter

glutamate

the discovery that the brain contains specific receptors for manufactured opiate drugs, such as morphine, implies that the body must make an ____ substance to interact with the same receptors

endogenous

choline acetyltransferase is involved in the synthesis of

acetylcholine

muscarinic receptors

may be excitatory or inhibitory

damage to the locus coeruleus would result in decreased production of

norepinephrine

a major origin of projections that respond to the neurotransmitter serotonin is the

raphe nucleus

in the mammalian brain, the major inhibitory neurotransmitter is

GABA

drugs that block GABA receptors tend to cause

seizures

most antipsychotic medications act by blocking ____ receptors

dopaminergic

the antipsychotic drug haloperidol is particularly selective for dopamine ____ receptors

D₂

heroin is a strong, addictive pain killer. when injected into the ____, the drug binds to ____ and causes strong analgesia

periaqueductal gray; opioid receptors

the mood-stabilizing drug lithium acts by

altering second-messenger systems

the venom of the black widow spider causes an increased release of

acetylcholine

you discover a compound that has a similar molecular structure to amphetamine. this compound will probably affect

catecholamine

a person who develops involuntary contractions of some muscles after walking barefoot in the woods may have been exposed to

tetanospasmin

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

which drug is used to treat people who have become addicted to heroin

methadone

the affinity of a drug may be quantified by adding molecules of the drug to a solution containing receptors and then determining the concentration required to bind

half of the receptors

normal growth of the body is stimulated not only by growth hormone but also by ___, which are released by the ____

somatomedins; liver

sympathetic nervous system activation leads to the release of ___ from the adrenal medulla

epinephrine and norepinephrine

the anterior pituitary is also known as the

adenohypophysis

if a person does not release sufficient amounts of oxytocin and vasopressin, the sources of the problem are likely to be found in the ____ or the ____

hypothalamus; posterior pituitary

the two hormones secreted by the pancreas (islets of langerhans) are

insulin and glucagon

neuromodulators

are released into synapses and act gradually

which of the following is an amine hormone?

• growth hormone

• thyroxine

• prolactin

• glucagon

thyroxine

neuronal and hormonal communication both involve

specialized receptor molecules

compared to neurotransmitters, hormone effects are generally

more widespread in the body

the principal hormones of the adrenal medulla are ___ and ____, which are secreted in response to signals from the ___

epinephrine; norepinephrine; sympathetic nervous system

which statement regarding gene expression is true?

• gene expression in vertebrates is a predetermined result of mitotic lineages

• environmental factors, including experience, affect gene expression and thus cell differentiation

• in vertebrates, gene expression in neural cells is independent of signals from the external environment

• gene expression and cell differentiation in C. elegans is regulated by cell-cell interactions

environmental factors, including experience, affect gene expression and thus cell differentiation

a relative insufficiency of oxygen is called

hypoxia

most of the mitosis that will give rise to the nervous system takes place in the

ventricular layer

which process occurs to only a limited extent after birth

c. Neurogenesis

which statement about apoptosis is true?

• it results from a molecular cascade in which a protein is released from mitochondria

• it refers to any kind of cell death

• it results from the inhibition of calcium entry into the cell

• it results from a larger-than-normal availability of target neurons

it results from a molecular cascade in which a protein is released from mitochondria

radial glial cells stretch between the ____ and ____ surfaces of the developing nervous system

inner; outer

certain growing axons are prevented from crossing the midline by the ___ action of the protein ____

chemorepellent; slit

which of the following is(are) not associated with growth cones?

• filopodia

• dendrites

• axons

• mitotic lineage

mitotic lineage

experience is an important factor in determining

which synapses are maintained

which statement describes evidence of epigenetic effects on gene expression?

• identical twins have identical genes and identical phenotypes

• synaptic remodeling proceeds in a caudal to rostral direction

• monocular deprivation can lead to blindness in that eye

• mice raised by foster parents behave more like their foster parents than their genetic parents

mice raised by foster parents behave more like their foster parents than their genetic parents

for most senses, the sensory pathway

passes through the thalamus

the progressive loss of sensitivity of a sensory receptor as a consequence of sustained stimulation is also known as

adaptation

according to the range fractionation hypohesis,

specific nerve cells can act as specialists in particular segments of an intensity scale

the translation of stimulus energy into nerve cell impulses is called

coding

the generator potential produced by a pacinian corpuscle in response to mechanical stimulation is

proportional to the stimulus intensity

the brain can differentiate between each sensory modality because

the action potentials for each one is sent along separate nerve tracts

most sensory fibers do not fire more than

1200 impulses per second

the term “adequate stimulus” refers to

the type of stimulus for which a given sensory system is particularly adapted

which portion of the body is represented most medially in the somatosensory cortex?

leg

cortical neurons that respond to information from more than one sensory modality are known as

polymodal cells