Question 1

Parasympathetic preganglionic neurons release the neurotransmitter ; sympathetic preganglionic neurons release the neurotransmitter _ .

Accepted Answer

Both parasympathetic and sympathetic preganglionic neurons release acetylcholine.

Question 2

Which of the following best describes the general arrangement of the efferent limb of the autonomic nervous system?

Accepted Answer

The efferent limb of the autonomic nervous system consists of two neurons in series. The first neuron, located in the CNS, synapses with the second neuron in a ganglion outside the CNS. The second neuron then synapses with the effector organ (smooth muscle, cardiac muscle, or glands).

Question 3

Myasthenia gravis primarily affects women and its defining characteristic is fatigue of unusually rapid onset and severity following the use of certain muscle groups. What symptoms below best allude to the set of muscles affected by this disease?

Accepted Answer

Myasthenia gravis primarily affects voluntary muscles, especially those controlling the eyes, face, and throat, leading to symptoms like drooping eyelids, difficulty speaking, and swallowing.

Question 4

The opening of a cation channel that allows both Na+ and K+ to move through will cause the membrane to _ _ because of the _.

Accepted Answer

The membrane will depolarize because the electrochemical gradient for Na+ is greater than that for K+, leading to more Na+ influx than K+ efflux.

Question 5

Students who suffer from test anxiety often have some of the following symptoms: the need for frequent urination, dilated pupils, and a dry mouth. What branch of the autonomic nervous system would cause these symptoms?

Accepted Answer

The sympathetic branch of the autonomic nervous system is responsible for the "fight or flight" response, which includes symptoms like frequent urination, dilated pupils, and dry mouth.

Question 6

What is the primary mode of action of curare?

Accepted Answer

Curare acts as a neuromuscular blocking agent by competitively inhibiting acetylcholine from binding to nicotinic cholinergic receptors at the neuromuscular junction, preventing muscle contraction.

Question 7

Which statement best describes the results of the autoimmune disease myasthenia gravis?

Accepted Answer

Myasthenia gravis is characterized by a decrease in the number of functional acetylcholine receptors on the muscle cell surface, impairing the muscle's ability to respond to acetylcholine.

Question 8

Located entirely within the autonomic ganglia, cells that modulate the flow of information to the target organ are called neurons.

Accepted Answer

Intrinsic neurons are located entirely within the autonomic ganglia and modulate the flow of information to the target organ.

Question 9

Where are most of the autonomic nervous system control centers located?

Accepted Answer

The autonomic nervous system control centers are primarily located in the brainstem, which regulates vital functions such as heart rate, blood pressure, and respiration.

Question 10

Scopolamine is a muscarinic antagonist that acts by blocking muscarinic acetylcholine receptors. Although it is not clear how scopolamine prevents nausea and vomiting due to motion sickness, which statement below best describes the mechanism of action for this drug?

Accepted Answer

Scopolamine blocks muscarinic acetylcholine receptors, preventing communication between the vestibular system and the vomiting center in the brain, which helps prevent motion sickness.

Question 11

The autonomic nervous system innervates all the following effector organs and tissues EXCEPT

Accepted Answer

Skeletal muscles are innervated by the somatic nervous system, not the autonomic nervous system.

Question 12

Parasympathetic preganglionic neurons travel in what nerves?

Accepted Answer

Parasympathetic preganglionic neurons travel in both cranial nerves (such as the vagus nerve) and pelvic nerves.

Question 13

In what class of autonomic neuron and within what organelle is the enzyme monoamine oxidase located?

Accepted Answer

Monoamine oxidase is located in the mitochondria of sympathetic postganglionic neurons, where it plays a role in the breakdown of neurotransmitters such as norepinephrine.

Question 14

Adrenergic receptors with the greatest affinity for epinephrine are receptors.

Accepted Answer

Beta 2 adrenergic receptors have the greatest affinity for epinephrine compared to other adrenergic receptors.

Question 15

Preganglionic and postganglionic sympathetic neurons are anatomically arranged in what three patterns?

Accepted Answer

Preganglionic and postganglionic sympathetic neurons are anatomically arranged in three patterns: sympathetic chains, those that innervate the adrenal medulla, and collateral ganglia.

Question 16

Which of the following is indicative of the relative release of catecholamines from the adrenal medulla?

Accepted Answer

The adrenal medulla primarily releases catecholamines in the ratio of approximately 80% epinephrine to 20% norepinephrine.

Question 17

fi2 adrenergic receptor agonists are used to treat acute asthma symptoms by eliciting a response similar to , which has a greater affinity for fi2 receptors and leads to dilation of the respiratory pathways.

Accepted Answer

Epinephrine has a greater affinity for beta-2 adrenergic receptors, leading to bronchodilation and relief of asthma symptoms.

Question 18

Sympathetic ganglia that are linked together and run in parallel on either side of the spinal column are called

Accepted Answer

The sympathetic chains or trunks are a series of interconnected ganglia located on either side of the spinal column, forming part of the sympathetic nervous system.

Question 19

People who have done a lot of endurance training can have a resting heart rate of 50 beats per minute compared to the normal resting heart rate of 70- 80 beats per minute. This decreased heart rate in trained individuals is the partly result of

Accepted Answer

Endurance training enhances parasympathetic (vagal) activity and reduces sympathetic activity at rest, leading to a lower resting heart rate.

Question 20

Which of the following physiological responses is associated with an elevation in parasympathetic nervous system activity?

Accepted Answer

The parasympathetic nervous system is responsible for "rest and digest" functions, which include enhancing digestion and nutrient absorption.

Quiz 11: The Nervous System: Autonomic and Motor Systems