Mastering A&P – Flashcards

What is the function associated with the indicated neural activity? (Synaptic Activity)

Ions are unequally distributed across the plasma membrane of all cells. This ion distribution creates an electrical potential difference across the membrane. What is the name given to this potential difference?

Sodium and potassium ions can diffuse across the plasma membranes of all cells because of the presence of what type of channel?

On average, the resting membrane potential is -70 mV. What does the sign and magnitude of this value tell you?

The plasma membrane is much more permeable to K+ than to Na+. Why?

The resting membrane potential depends on two factors that influence the magnitude and direction of Na+ and K+ diffusion across the plasma membrane. Identify these two factors.

What prevents the Na+ and K+ gradients from dissipating?

The membranes of neurons at rest are very permeable to _____ but only slightly permeable to _____.

During depolarization, which gradient(s) move(s) Na+ into the cell?

What is the value for the resting membrane potential for most neurons?

The Na+-K+ pump actively transports both sodium and potassium ions across the membrane to compensate for their constant leakage. In which direction is each ion pumped?

The concentrations of which two ions are highest outside the cell.

In a neuron, sodium and potassium concentrations are maintained by the sodium-potassium exchange pump such that __________.

The sodium-potassium exchange pump transports potassium and sodium ions in which direction(s)?

Leak channels allow the movement of potassium and sodium ions by what type of membrane transport?

The electrochemical gradient for potassium ions when the transmembrane potential is at the resting potential (-70 mV) is caused by what?

What is the electrochemical gradient of an ion?

What is the function associated with the indicated neural activity? (Action Potential)

The events that occur at a functioning cholinergic synapse cause _____________ .

Which type of ion channel is always open?

The sodium-potassium exchange pump stabilizes resting potential at about __________.

Where do most action potentials originate?

What opens first in response to a threshold stimulus?

What characterizes depolarization, the first phase of the action potential?

What characterizes repolarization, the second phase of the action potential?

What event triggers the generation of an action potential?

What is the first change to occur in response to a threshold stimulus?

What type of conduction takes place in unmyelinated axons?

An action potential is self-regenerating because __________.

Why does regeneration of the action potential occur in one direction, rather than in two directions?

What is the function of the myelin sheath?

What changes occur to voltage-gated Na+ and K+ channels at the peak of depolarization?

In which type of axon will velocity of action potential conduction be the fastest?

Where in the neuron is an action potential initially generated?

The depolarization phase of an action potential results from the opening of which channels?

The repolarization phase of an action potential results from __________.

Hyperpolarization results from __________.

What is the magnitude (amplitude) of an action potential?

Action potential propagation begins (is first generated at) what region of a neuron?

Where are action potentials regenerated as they propagate along an unmyelinated axon?

The movement of what ion is responsible for the local currents that depolarize other regions of the axon to threshold?sodium (Na+)

In an unmyelinated axon, why doesn't the action potential suddenly "double back" and start propagating in the opposite direction?

Approximately how fast do action potentials propagate in unmyelinated axons in humans?

In contrast to the internodes of a myelinated axon, the nodes __________.

Where are action potentials regenerated as they propagate along a myelinated axon?

The node-to-node "jumping" regeneration of an action potential along a myelinated axon is called __________.

How do action potential propagation speeds in myelinated and unmyelinated axons compare?

Multiple sclerosis (MS) is a disease that stops action potential propagation by destroying the myelin around (normally) myelinated axons. Which of the following best describes how MS stops action potential propagation?

During propagation of the action potential, __________.

Compared to type A axons, type C axons are __________.

Which of these axons will conduct an action potential most quickly?

The small space between the sending neuron and the receiving neuron is the

A molecule that carries information across a synaptic cleft is a

When calcium ions enter the synaptic terminal,

When neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron,

If a signal from a sending neuron makes the receiving neuron more negative inside,

In a synapse, neurotransmitters are stored in vesicles located in the __________.

An action potential releases neurotransmitter from a neuron by opening which of the following channels?

Binding of a neurotransmitter to its receptors opens __________ channels on the __________ membrane.

Binding of the neurotransmitter to its receptor causes the membrane to __________.

The mechanism by which the neurotransmitter is returned to a presynaptic neuron's axon terminal is specific for each neurotransmitter. Which of the following neurotransmitters is broken down by an enzyme before being returned?

Which of the following is an example of a presynaptic cell?

What separates the presynaptic and postsynaptic cells at a chemical synapse?

Which of the following best describes the role of calcium in synaptic activity?

What is the role of neurotransmitter at a chemical synapse?

What mechanism releases neurotransmitter from presynaptic neurons?

What type of channel in the postsynaptic membrane binds neurotransmitter?

What is the primary role of the enzyme acetylcholinesterase (AChE) at a cholinergic synapse?

Events that occur at a cholinergic synapse are listed here, but they are arranged in an incorrect order. Choose the correct order of these events below. (a) Calcium influx triggers exocytosis of ACh. (b) An action potential depolarizes the synaptic terminal. (c) ACh is removed by AChE. (d) ACh binds to receptors on the postsynaptic membrane.

The effect of a nerve impulse on a postsynaptic neuron depends on the __________.

EPSPs and IPSPs summate at the __________.

Which of these neurotransmitters does not bind to a plasma membrane receptor?

Which of these neurotransmitters is released at CNS adrenergic synapses?

The neurotransmitter glutamate opens channels that are permeable to sodium ions. What effect does glutamate produce on a postsynaptic neuron?

The simplest level of information processing takes place at the __________.

If EPSPs summate to a sustained value above threshold, then the initial segment will __________.

EPSPs are ___________.

If a nerve cell receives many IPSPs at the same time, __________.

What is the function of the brain structure indicated by the arrow? (cerebrum)

What is the function of the brain structure indicated by the arrow? (Pons)

What is the function of the brain structure indicated by the arrow? (Cerebellum)

The cerebrum develops from the embryonic __________.

In the adult brain, which is the largest region?

What is indicated by the arrow? (Arachnoid mater)

What is indicated by the arrow? (Arachnoid granulation)

What is indicated by the arrow? (Choroid plexus)

The CSF leaves the CNS and enters the circulation at the __________.

The CSF circulates within the __________.

Which of these is not a property of cerebrospinal fluid (CSF)?

Which of these statements about the medulla oblongata is true?

Which of these is found in the pons?

Making rapid postural adjustments is a major function of the __________.

The huge, highly branched neurons known as Purkinje cells are found in the __________.

The cerebellum __________.

Which structure connects the left and right cerebral hemispheres?

What structure secretes the hormone melatonin?

Which of these is not a property of the epithalamus?

The largest component of the diencephalon is the __________.

Which of these is not a property of the limbic system?

Which of the following cranial nerves is classified as mixed nerve?

Which of the following cranial nerves relays information regarding hearing, motion and balance?

Which of the following cranial nerves innervates the tongue musculature?

The region of cerebrum anterior to the central sulcus is the __________ lobe.

The region of cerebral cortex inferior to the lateral sulcus is the __________ lobe.

The primary somatosensory cortex is found on the __________.

The cerebrum is divided into two hemispheres by the __________.

Which of these cranial nerves does not carry motor impulses to the eyes?