EXAM 1-BP

Pok is measuring the resting potential of neurons. Approximately what should she measure as the resting potential?

-70 millivolts

What does the all-or-none law state?

All action potentials have same amplitude and velocity

Which type of glia release chemicals that modify the activity of neighboring neurons?

Astrocytes

When do sodium channels close?

At the peak of the AP

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

Ca into the cell

Action potentials are produced in the dendrites of neurons (T or F)

False

Each neuron releases one and only one NT

False

Schwann cells produce the myelin sheath in the central nervous system, and oligodendrocytes do so in the periphery (T or F)

False

Which of the following cranial nerves plays a role in the sensation of taste?

Glossopharyngeal

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

Hyperpolarization

What ordinarily prevents extensor muscles from contracting at the same time as flexor muscles?

Inhibitory synapses in the spinal cord

Glutamate opens sodium gates, enabling sodium ions to enter the postsynaptic cell. What type of effect is this?

Ionotropic

What is the function of the enzyme acetylcholinesterase?

It breaks acetylcholine down into components for recycling.

What is the importance of the myelin sheath?

It speeds up the AP down the length of the axon

Which type of glia remove waste material in the NS?

Microglia

What is the primary neurotransmitter of the sympathetic nervous system?

Norepinephrine

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

Potassium

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

Thalamus

Which statement correctly described how the concentration and electrical gradients act on potassium when the neuron is at rest?

The concentration gradient moves potassium out, and the electrical gradient moves it in.

Which statement correctly described how the concentration and electrical gradients act on sodium when the neuron is at rest?

The concentration gradient moves sodium in, and the electrical gradient moves it in

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

What happens to voltage-gated channels when the membrane is depolarized?

They open

After one frog's heart has been stimulated to increase its rate, an extract of fluid from that heart can make a second frog's heart beat faster. What conclusion did Otto Loewi draw from these results?

Transmission at synapses is a chemical event

Whether or not a neurotransmitter is excitatory depends on the response of the postsynaptic receptor (T or F)

True

Dr. O'Reilly is trying to produce hyperpolarization in neurons. What should she do?

Use a microelectrode to apply a negative charge

Damage to the basal ganglia would most likely result in ____.

a movement disorder

Which statement about autoreceptors is accurate?

activated autoreceptors decrease neurotransmitter release

Before the action potential is initiated, when the neuron is at rest, sodium channels ____.

are closed and dont allow sodium to pass through

"Second messengers" carry their messages to ____.

areas within the postsynaptic cell

Terrance went to the dentist and was given some Novocain. This prevented him from feeling pain because the drug ____.

attached to sodium channels, blocking sodium from entering and stopping the action potential from sending a pain message

As a general rule, axons convey information ______.

away from their own cell body

"Transporter" proteins transport neurotransmitters ____.

back into presynaptic neuron

What mechanism prevents or slows some chemicals from entering the brain, while allowing others to enter?

blood-brain barrier

What do temporal summation and spatial summation have in common?

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

The central nervous system is made up of _____.

brain and spinal cord

What determines whether a neuron has an action potential?

combines effects of EPSPs and IPSPs

A hormone is a chemical that is____.

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

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

decrease the number of positively charged ions within the cell

Neuropeptides differ from other neurotransmitters in that they are mostly released from _____.

dendrites

The tree-like branches of a neuron that receive information from other neurons are called _____.

dendrites

The concentration gradient refers to the _____.

difference in distribution for various ions between the inside and outside of the membrane

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

If Geri had disruptions to her limbic system, she would likely have problems with _____.

emotional behaviors

A neuron excretes neurotransmitters through its membrane by a process called ____.

exocytosis

Most of the brain's excitatory ionotropic synapses release ____ .

glutamate

If the prefrontal cortex is damaged, an individual may ____.

have difficulty remembering where they just placed the keys

An individual has difficulty remembering certain things after brain damage, but all memories stored before the damage are intact. The brain area most likely damaged is the ____.

hippocampus

The role of the pituitary gland is to make and release ______.

hormones into the bloodstream

Releasing hormones are synthesized in the

hypothalamus

People with damage of the parietal cortex tend to have trouble ____.

locating objects in space

An important difference between ionotropic and metabotropic effects is that _____.

metabotropic effects are slower and longer lasting

In which area of the brain would one find the tectum, tegmentum, superior and inferior colliculi, and substantia nigra?

midbrain

Damage to any hypothalamic nucleus leads to abnormalities in _____.

motivated behaviors

Santiago Ramon y Cajal demonstrated that _____.

neurons are separate from one another

In myelinated axons, the action potential starts at the first ____.

node of ranvier

When the potential across a membrane reaches threshold, the sodium channels ____.

open to let sodium enter the cell rapidly

temporal summation and spatial summation _____.

ordinarily occur together

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

peripheral NS

The membrane of a neuron is composed of ____.

phospholipids with embedded proteins

What provides the building blocks for synthesizing nearly all neurotransmitters?

proteins found in the diet

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

refractory period

After damage to the dorsal roots of the spinal cord, an individual will suffer what kind of loss?

sensation from the affected body area

What is the proper order of neurons in the reflex arc, from first to last?

sensory neuron, interneuron, motor neuron

Hormones exert their effects ____.

similarly to metabotropic neurotransmitters

Most of the neuron's metabolic work occurs in the _____.

soma

Desirae touched a plate, and it was hot. Which part of her nervous system conveyed this sensory information?

somatic

Karissa is in the lab working and was able to produce a reflexive response by stimulating several different locations all at one time. She successfully demonstrated ______.

spatial summation

You are walking after dark when a sudden noise frightens you. Your heart pounds, your pulse races, and your breathing rate increases. These responses are due to your ____.

sympathetic NS

The sweat glands, adrenal glands, and muscles that constrict blood vessels have input from only the ____.

sympathetic nervous system

Dr. Andrus has demonstrated that a certain reflex doesn't occur in response to a single stimulus but will occur if multiple stimuli are presented in rapid succession. What has Dr. Andrus demonstrated?

temporal summation

Kimiko has been diagnosed with cortical blindness. She has had damage to _____.

the occipital cortex

Acetylcholine is the only neurotransmitter released by ___.

the parasympathetic nervous system's postganglionic axons

After the peak of an action potential, what prevents sodium ions from continuing to enter the cell?

the sodium gates in the membrane close.

A membrane produces an action potential whenever the potential across it reaches what level?

the threshold of excitation

What do the corpus callosum and anterior commissure have in common?

they both connect the 2 hemispheres

Which statement is true of EPSPs?

they decay over time and space.

How do EPSPs affect the firing rate of neurons?

they increase it above the spontaneous firing rate

The resting potential of a neuron is the ____.

total amount of negative charge inside the neuron relative to the outside

Why is the speed of conduction through a reflex arc slower than the speed of conduction of an action potential along an axon?

transmission between neurons at synapses is slower than transmission along axons

Prior to their release, NTs are typically stored in ____.

vesicles in the presynaptic neuron