Physiological Psychology Final Exam

If you were to accidentally touch a hot stove with your hand, you would quickly pull your hand away. The information carried to the muscles in your arm to make them contract was carried by ____.​

efferent neurons

What leads to Korsakoff's syndrome?​

thiamine deficiency due to chronic alcoholism

Molecules that can cross the blood-brain barrier are usually ____.​

​molecules that can dissolve in the fats of the capillary walls

The two basic kinds of cells in the nervous system are _____.​

neurons and glia

Which type of glia builds myelin sheaths around axons in the periphery of the body?​

Schwann cells

____ in the brain and spinal cord and ____ in the periphery are specialized types of glia that build the myelin sheaths that surround neurons.​

Oligodendrocytes; Schwann cells

Glucose enters the brain via which type of transport?​

​active transport

Why does the brain need thiamine?​

​to enable it to metabolize glucose

What type of neuron in the pons receives information only from other cells in the pons and sends information only to other cells in the pons?​

intrinsic

Neurons differ most strongly from other body cells in their ____.​

shape

What structure is composed of two layers of fat molecules that are free to flow around one another?​

the membrane

An axon has many branches, each of which swells at its tip. These are known as ____.​

presynaptic terminals

What happens to a virus that manages to cross the blood-brain barrier and enter the brain?​

It remains there and may cause negative effects several years later.

The insulating material that covers many vertebrate axons is called the ____.​

myelin sheath

As a general rule, axons convey information ____.​

away from their own cell body

Why do neurons rely so heavily on glucose as their source of nutrition?​

​Other fuels do not readily cross the blood-brain barrier.

The cell membrane is composed of two layers of _____.​

fat

A presynaptic terminal is also known as ____.​

an end bulb

The surface of a dendrite is lined with specialized junctions through which the dendrite receives information from other neurons. What are these junctions called?​

synaptic receptors

The major disadvantage of a blood-brain barrier is that ____.​

​certain required chemicals must be actively transported

Local anesthetic drugs attach to the sodium channels of the membrane, which ____.​

prevents sodium ions from entering and stopping action potential

When a neuron's membrane is at rest, the concentration gradient tends to move potassium ____ the cell and the electrical gradient tends to move it ____ the cell.​

into; out of

The net effect of each cycle of the sodium-potassium pump is to ____.​

decrease the number of positively charged ions within the cell

What occurs when a stimulus shifts the potential inside a neuron from the resting potential to a more negative potential?​

​hyperpolarization

When the neuronal membrane is at rest, the potassium leak channels ____.​

permit potassium ions to pass slowly

According to the all-or-none law, ____.​

​once an axon reaches threshold, the amplitude and velocity of an action potential are nearly equal each time

In the normal course of an action potential, ____.​

​sodium remains much more concentrated outside than inside the neuron

What occurs when depolarization is less than the cell's threshold?​

Sodium crosses the membrane only slightly more than usual.

The primary feature of a neuron that prevents the action potential from traveling back from where it just passed is the ____.​

​refractory period

Voltage-activated channels are channels for which a change in the voltage across the membrane alters their ____.​

​permeability

Which of the following describes the transmission of information in a local neuron?​

The signal decreases in strength as it travels.

When a membrane is at rest, what attracts sodium ions to the inside of the cell?​

​both an electrical gradient and a concentration gradient

What is the approximate resting potential of the inside of a neuron's membrane, relative to the outside?​

-70 millivolts

The resting potential of a neuron refers to the ____.​

net negative charge on the inside of the neuron

What is one major cause for the resting potential of a neuron's membrane?​

the sodium-potassium pump

The action potential of a neuron depends mostly on what movement of ions?​

sodium ions entering the cell

The all-or-none law states that ____.​

a neuron produces an action potential of maximal strength, or none at all

When a neuron's membrane is at rest, the concentration gradient tends to move sodium ____ the cell and the electrical gradient tends to move it ____ the cell.​

​into; into

The neuron will produce an action potential only if the depolarization exceeds the ____.​

threshold of excitation.

The idea that a neuron's membrane is polarized refers to a difference in electrical potential between ____.​

the inside and the outside of the membrane

The "spontaneous firing rate" of a neuron refers to ____.

​its rate of producing action potentials even when it is not stimulated

Which statement is TRUE of EPSPs?​

​They decay over time and space.

Which process will most likely result in an IPSP?​

​chloride ions entering the cell

Even at rest, most neurons have periodic production of action potentials, known as the ____.​

​spontaneous firing rate

When a vertebrate animal contracts the flexor muscles of a leg, it relaxes the extensor muscles of the same leg. Sherrington considered this evidence for the existence of ____.​

​inhibitory messages

On the basis of what evidence were the properties of synapses first inferred?​

​behavioral observations

Increased permeability to which type of ion would most likely result in an IPSP?​

​potassium

Which pattern of post-synaptic excitation will most likely result in an action potential?

​rapid sequence of EPSPs

A normal, healthy animal never contracts the flexor muscles and the extensor muscles of the same leg at the same time. Why not?​

​When the interneuron sends excitatory messages to one, inhibitory messages go to the other.

A graded depolarization is known as an ____.​

EPSP

In a reflex arc, the coordination between contraction of certain muscles and relaxation of others is mediated by ____.​

​interneurons

Inhibitory synapses on a neuron ____.​

​hyperpolarize the postsynaptic cell

Depolarization is to ____ as hyperpolarization is to ____.​

​excitation; inhibition

What causes an EPSP?​

the opening of sodium channels

To measure temporal summation in single cells, researchers ____.​

​record depolarizations of the postsynaptic neuron

Specialized junctions between neurons are called ____.​

​synapses

What do temporal summation and spatial summation have in common?

Both enable a reflex to occur in response to weak stimuli.

Temporal summation most likely occurs with ____.​

​rapid succession of subthreshold excitation

An EPSP is to ____ as an IPSP is to ____.​

depolarization; hyperpolarization

Sherrington deduced that transmission at a synapse must be slower than conduction along an axon. This was based on what kind of evidence?

​the speed of reflexive responses

When an action potential reaches the end of an axon, the depolarization causes what ionic movement in the presynaptic cell?​

​calcium into the cell

The basic building blocks for the majority of neurotransmitters are ____.​

amino acids

A drug that inhibits the action of the enzyme acetylcholinesterase will have the effect of ____.

prolonging the action of acetylcholine at its synapses

Which terms refers to a chemical that binds to another chemical?​

​ligand

Loewi demonstrated that synapses operate by the release of chemicals by ____.

collecting fluid from a stimulated frog's heart, transferring it to another frog's heart, and measuring that heart rate

Which neurotransmitter is released by stimulated neurons to dilate the blood vessels?

nitric oxide

"Second messengers" carry their messages to ____.​

areas within the presynaptic cell

The presynaptic terminal stores high concentrations of neurotransmitter molecules in ____.​

​vesicles

Which event is most likely to be dependent on ionotropic effects?​

​rapid muscle contraction

A receptor can directly open a channel and thereby exert a(n) ____ effect, or it can produce slower but longer ____ effects.​

​ionotropic; metabotropic

What is the function of the enzyme acetylcholinesterase?​

It breaks acetylcholine down into components for recycling.

What do dopamine, norepinephrine, and epinephrine share in common?​

They are all synthesized from the same amino acids.

Adrenocorticotropic hormone (ACTH) controls secretions of the ____.​

​adrenal cortex

What makes nitric oxide unique among neurotransmitters?​

​It is a gas.

Releasing hormones are synthesized in the ____ and released in the ____.​

​hypothalamus; anterior pituitary

Vesicles are located ____.​

​in presynaptic terminals

The main advantage of a neuron releasing more than one neurotransmitter is that:​

​it can send more complex messages

What happens when a neurotransmitter is released by a presynaptic cell?​

​The neurotransmitter passively spreads across the synaptic cleft.

What happens to acetylcholine after it attaches to a receptor on the postsynaptic cell?​

​It is broken down into two components.

Ionotropic effects ____.​

​may depolarize or hyperpolarize the postsynaptic membrane

A metabotropic synapse, by way of its second messenger, ____.​

​can influence activity in much or all of the postsynaptic cell

A hormone is a chemical that is ____.​

​conveyed by the blood to other organs, whose activity it influences

Avoiding foods with lecithin, such as eggs and peanuts, would affect the levels of which neurotransmitter the most?

​acetylcholine

Compared to ionotropic effects, metabotropic effects are ____.​

​slower and longer lasting

The anterior pituitary is composed of ____ and the posterior pituitary is composed of ____.​

​glandular tissue; neural tissue

Research indicates that the behavioral effects of the cerebellum may be due to its role in ____.

focusing attention and organizing sensory inputs

Membranes that surround the brain and spinal cord are called ____.

meninges

The nucleus basalis is a key part of the brain's system for ____.

attention

The hippocampus plays a major role in ____.​

​memory

As axons from the spinal cord enter the skull, which structure do they enter?

​medulla

One function of the thalamus is to ____.

relay sensory information to the cerebral cortex

If one structure is on the left side of the body and another is on the right, they are said to be ____ to each other.

contralateral

​Together, the somatic nervous system and the autonomic nervous system make up the ____ nervous system.

peripheral

​The ascending portion of the reticular formation ____.

​increases arousal and attention

Which structure receives input from the hypothalamus and basal ganglia and sends axons that release acetylcholine to widespread areas in the cerebral cortex?

​nucleus basilis

​Which structure provides the main source of input to the cerebral cortex?

thalamus

Which structure consists of the medulla, the pons, and the cerebellum?

​hindbrain

An impairment of eating, drinking, temperature regulation, or sexual behavior suggests possible damage to which brain structure?

hypothalamus

​A cross section of the spinal cord indicates that gray matter is ____.

​densely packed with cell bodies and dendrites

Superior colliculus is to ____ as inferior colliculus is to ____.

vision; hearing