Human Anatomy and Physiology : Help with Neurotransmitter and Receptor Physiology

Study concepts, example questions & explanations for Human Anatomy and Physiology

varsity tutors app store varsity tutors android store

Example Questions

← Previous 1 3

Example Question #1 : Help With Neurotransmitter And Receptor Physiology

Which of the following is NOT a strategy for removing neurotransmitters from the synaptic cleft?

Possible Answers:

The neurotransmitter is pumped back into the presynaptic neuron

The neurotransmitter is destroyed by enzymes

The neurotransmitter diffuses out of the cleft

Neurotransmitters are recycled inside the postsynaptic neuron

Correct answer:

Neurotransmitters are recycled inside the postsynaptic neuron

Explanation:

Neurotransmitters will never enter the postsynaptic neuron. They will attach to receptors on the membrane of the postsynaptic neuron, release, and then be dealt with while in the synaptic cleft. In some instances, the neurotransmitter simply diffuses away from the synapse, but in most cases synaptic proteins help to recycle the molecules. Some enzymes will break the neurotransmitter into parts, which then reenter the presynaptic neuron and are reassembled. Acetylcholinesterase is a common example of this type of enzyme. Other neurons use membrane pumps to retrieve neurotransmitter from the synaptic cleft.

Example Question #2 : Help With Neurotransmitter And Receptor Physiology

Which of the following statements is true concerning neurotransmitters?

Possible Answers:

Neurotransmitters attach to receptors inside the postsynaptic neuron

The neurotransmitters remain attached to the postsynaptic neuron in order to prevent multiple binding to a single receptor

GABA and acetylcholine will have similar effects on neuron stimulation

An influx of sodium stimulates the release of neurotransmitters into the synaptic cleft

Calcium will enter the presynaptic neuron, stimulating the release of neurotransmitters into the synaptic cleft

Correct answer:

Calcium will enter the presynaptic neuron, stimulating the release of neurotransmitters into the synaptic cleft

Explanation:

Once an action potential has reached the end of the presynaptic neuron, voltage-gated calcium channels are stimulated, allowing calcium to enter the neuron. This influx of calcium stimulates the release of neurotransmitters into the synaptic cleft.

The neurotransmitters then bind to receptors on the surface of the postsynaptic neuron to generate small electrical stimuli. The sum of these stimuli must reach threshold in order for an action potential to be generated.

GABA and acetylcholine are two common neurotransmitters. GABA generally inhibits the postsynaptic neuron, while acetylcholine generally excites/stimulates the postsynaptic neuron.

Example Question #3 : Help With Neurotransmitter And Receptor Physiology

Which of the following activates muscarinic receptors in parasympathetic nervous tissue?

Possible Answers:

Glycine

Serotonin

Norepinephrine

Glutamate

Acetylcholine

Correct answer:

Acetylcholine

Explanation:

Acetylcholine activates muscarinic receptors in postganglioinic parasympathetic nervous tissue and nicotinic receptors in skeletal muscle fibers, and preganglionic sympathetic and parasympathetic nervous tissue.

Example Question #4 : Help With Neurotransmitter And Receptor Physiology

Which of the following is a type of acetylcholine receptor?

Possible Answers:

Adrenergic

Muscarinic

Dopaminergic

Glutaminergic

Correct answer:

Muscarinic

Explanation:

Muscarinic acetylcholine receptors (mAChRs) are found in the G protein-receptor complexes in the cell membrane of certain neurons. The suffix -ergic means exhibiting or stimulating the activity of. For example, dopaminergic receptors bind to dopamine. 

Example Question #5 : Help With Neurotransmitter And Receptor Physiology

Neurotransmitters are used for communication between neurons. The neurotransmitters travel from the pre-synaptic membrane to the post-synaptic membrane packaged in __________, traveling through the __________.

Possible Answers:

vesicles . . . axons

vesicles . . . synaptic cleft

dendrites . . . neurotransmitter membrane

axons . . . synaptic cleft

Correct answer:

vesicles . . . synaptic cleft

Explanation:

Neurotransmitters are packaged in vesicles, traveling through the synaptic cleft (space between neurons) from the pre-synaptic membrane to the post-synaptic membrane, where they bind to their receptors and influence the post-synaptic membrane potential.

Example Question #6 : Help With Neurotransmitter And Receptor Physiology

The Renshaw cells in the spinal cord release which neurotransmitter?

Possible Answers:

GABA

Glutamate

Acetylcholine

Glycine

Dopamine

Correct answer:

Glycine

Explanation:

Renshaw cells are interneurons in the spinal cord that release the inhibitory neurotransmitter glycine.

Example Question #7 : Help With Neurotransmitter And Receptor Physiology

What are competitive inhibitors?

Possible Answers:

Molecules that alter the 3D shape of protein, which may be irreversible

Molecules that bind to active site and cannot be displaced by ligands

Molecules that bind covalently to protein and changes its activity

Molecules that compete directly with ligands by binding reversibly to the active site

Correct answer:

Molecules that compete directly with ligands by binding reversibly to the active site

Explanation:

Competitive inhibitors directly compete with ligands for the same binding sites (active sites). Irreversible inhibitors are molecules that bind irreversible to the active site. Covalent modulators are molecules that bind covalently to proteins and changes their activity. pH and temperature may alter the 3D shape of the protein and can be irreversible, while ligand binding, and competitive inhibition is a reversible process that involves the formation of weak, not covalent, bonds.

Example Question #8 : Help With Neurotransmitter And Receptor Physiology

Cholinergic neurons release which neurotransmitter?

Possible Answers:

Norepinephrine

Acetylcholine

Nitric oxide

Substance P

Correct answer:

Acetylcholine

Explanation:

Cholinergic neurons, whether in the sympathetic or parasympathetic nervous system, release acetylcholine as the neurotransmitter. Nonadrenergic, noncholinergic neurons include some postganglionic parasympathetic neurons of the gastrointestinal tract, which release substance P and nitric oxide. Adrenergic neurons release norepinephrine. 

Example Question #9 : Help With Neurotransmitter And Receptor Physiology

Which neurotransmitter is released by adrenergic neurons?

Possible Answers:

Acetylcholine

Norepinephrine

Nitric oxide

Substance P

Correct answer:

Norepinephrine

Explanation:

Norepinephrine is released by adrenergic neurons.

Cholinergic neurons release acetylcholine as their neurotransmitter (in the sympathetic or parasympathetic nervous system).

Nonadrenergic, noncholinergic neurons (which include postganglionic parasympathetic neurons of the gastrointestinal tract) release substance P and nitric oxide.

Example Question #10 : Help With Neurotransmitter And Receptor Physiology

The entry of which ion into the presynaptic terminal cause synaptic vesicles to release neurotransmitters into the synaptic cleft? 

Possible Answers:

Potassium 

Calcium 

Magnesium 

Acetylcholine 

Sodium 

Correct answer:

Calcium 

Explanation:

The depolarization of the presynaptic membrane causes voltage-gated calcium channels to enter from the extracellular space. This causes the synaptic vessels which are docked on the presynaptic terminal to fuse with the presynaptic membrane and release the neurotransmitter into the synaptic cleft. 

← Previous 1 3
Learning Tools by Varsity Tutors

Incompatible Browser

Please upgrade or download one of the following browsers to use Instant Tutoring: