Deck 19: Autonomic Nervous System

Question 1

Activity of the autonomic nervous system is

A) absent when we are sleeping or unconscious.
B) entirely independent of voluntary action.
C) under direct voluntary control.
D) not directly under voluntary control but may be controlled indirectly by voluntary action.
E) entirely independent of environmental conditions.

Answer 1

D

Question 2

The primary destination of autonomic neurons is

A) skeletal muscle fibers.
B) other neurons in the brain.
C) the body's organs and tissues.
D) the body's sensory receptors.
E) the motor cortex.

Answer 2

C

Question 3

The system associated with the 'fright, fight, and flight' response is the _______ system.

A) sympathetic
B) parasympathetic
C) cholinergic
D) limbic
E) autonomic ganglionic

Answer 3

A

Question 4

Ephedrine is a drug that affects the nervous system similarly to epinephrine. Knowing this, you would expect a person taking ephedrine to experience

A) symptoms such as reduced blood pressure, increased gut motility, and pupillary constriction.
B) symptoms such as increased blood pressure, reduced gut motility, and pupillary dilation.
C) a disruption of circadian rhythms.
D) increased appetite and/or overeating.
E) loss of muscular coordination.

Question 5

Compared to the sympathetic nervous system, the parasympathetic system

A) has a more general, widespread effect on the body.
B) has more focused, selective effects.
C) is more directly under voluntary control.
D) is less directly under voluntary control.
E) tends to be associated with emotions.

Question 6

The structure of autonomic ganglia can be characterized as

A) mainly convergent, with many preganglionic fibers innervating each ganglionic neuron.
B) mainly divergent, with each preganglionic fiber innervating many ganglionic neurons.
C) both convergent and divergent.
D) direct, with each preganglionic fiber innervating a single ganglionic neuron.
E) unknown, since the fibers are too entangled to map their connections.

Question 7

The axons of preganglionic neurons in the sympathetic system tend to be _______, while those in the parasympathetic system tend to be _______.

A) myelinated; unmyelinated
B) unmyelinated; myelinated
C) long; short
D) short; long
E) unipolar; multipolar

Question 8

Ganglia of the parasympathetic nervous system are usually located

A) close to the tissues or organs that they innervate.
B) inside the spinal cord.
C) close to the muscles that they control.
D) in the brainstem.
E) next to the spinal cord.

Question 9

Myelination of neurons in the autonomic nervous system is generally

A) present in the sympathetic nervous system, with parasympathetic neurons being unmyelinated.
B) absent, with most neurons being unmyelinated.
C) present on preganglionic neurons, with postganglionic neurons being unmyelinated.
D) present on postganglionic neurons, with preganglionic neurons being unmyelinated.
E) present on both preganglionic and postganglionic neurons

Question 10

Direct, rapid transmission at autonomic ganglia differs from that in the neuromuscular junction in that

A) the autonomic ganglia use nicotinic receptors while the neuromuscular junction uses muscarinic receptors.
B) the autonomic ganglion cells are activated by acetylcholine, while the neuromuscular junction uses glutamate.
C) unlike the neuromuscular junction, the autonomic ganglion cells are inhibited by presynaptic activity.
D) the autonomic ganglion cells are activated by epinephrine instead of acetylcholine.
E) the structure of nicotinic receptors in autonomic ganglion cells differs from those at the neuromuscular junction.

Question 11

The connection between autonomic ganglion neurons and their presynaptic neurons is such that

A) an action potential in any presynaptic neuron is capable of producing an action potential in the ganglion cell.
B) some "strong" presynaptic neurons can produce action potentials in the ganglion cell, while other "weak" neurons produce subthreshold potentials.
C) all presynaptic neurons produce subthreshold potentials that must summate to produce an action potential.
D) an action potential in any presynaptic neuron is capable of inhibiting any action potentials in the ganglion cell.
E) only g-protein coupled receptors are present on the ganglion cell, so presynaptic firing does not produce any direct changes in postsynaptic potential.

Question 12

Muscarinic ACh receptors

A) are not present in autonomic ganglion cells.
B) produce fast, direct activation of autonomic ganglion cells.
C) produce slow, long lasting activation of autonomic ganglion cells.
D) produce inhibition of autonomic ganglion cells.
E) are present in autonomic ganglion cells, but their function has not yet been determined.

Question 13

Nicotinic ACh receptors

A) are not present in autonomic ganglion cells.
B) produce fast, direct activation of autonomic ganglion cells.
C) produce slow, long lasting activation of autonomic ganglion cells.
D) produce inhibition of autonomic ganglion cells.
E) are present in autonomic ganglion cells, but their function has not yet been determined.

Question 14

In frogs, excitatory signaling in autonomic ganglion cells appears to be controlled by

A) neuropeptide Y and glutamate.
B) norepinephrine and gonadotropin-releasing hormone.
C) acetylcholine and nicotine.
D) glutamate and epinephrine.
E) acetylcholine and luteinizing hormone releasing hormone.

Question 15

Direct, rapid transmission at autonomic ganglia is produced when _______ is released, binding to _______ receptors.

A) epinephrine; nicotinic
B) norepinephrine, adrenergic
C) purines; P
D) acetylcholine, nicotinic
E) acetylcholine; muscarinic

Question 16

M-currents are involved in a(n)

A) fast, direct excitatory potential in post-ganglionic autonomic neurons.
B) slow, long-lasting depolarization in post-ganglionic autonomic neurons.
C) fast, direct inhibitory potential in post-ganglionic autonomic neurons.
D) slow, long-lasting hyperpolarization in post-ganglionic autonomic neurons.
E) initiation of long-term potentiation in post-ganglionic autonomic neurons.

Question 17

M-channels (or KCNQ or K_v7 channels) are permeable primarily to

A) magnesium.
B) sodium.
C) chloride.
D) calcium.
E) potassium.

Question 18

Activation of muscarinic ACh receptors causes M-channels to

A) open, allowing an influx of potassium.
B) open, allowing an influx of sodium.
C) open, allowing an efflux of potassium.
D) close, reducing the efflux of potassium.
E) close, reducing the influx of sodium.

Question 19

The closing of an M-channel has the effect of

A) depolarizing the cell.
B) hyperpolarizing the cell.
C) maintaining the cell's resting potential.
D) ending the activity of cyclic AMP.
E) None of the above

Question 20

The opening of an M-channel has the effect of

A) increasing the probability of an action potential.
B) decreasing the probability of an action potential.
C) lowering the resting potential of the cell.
D) increasing the magnitude of action potentials.
E) activation of cyclic AMP.

Question 21

Autonomic ganglion neurons switch from phasic-firing to tonic-firing when

A) M-channels are closed.
B) M-channels are opened.
C) Nicotinic ACh receptors are opened.
D) Nicotinic ACh receptors are closed.
E) C-cells are activated.

Question 22

The application of ACh to muscarinic receptors in autonomic ganglia would be expected to have this effect on the post-synaptic neuron.

A) Shift from tonic firing to phasic firing
B) Shift from phasic firing to tonic firing
C) Suppress all firing activity
D) No effect on firing activity
E) Induction of long-term potentiation

Question 23

In a neuron's resting state, M-channels are likely to be

A) closed, reducing potassium conductance.
B) closed, reducing chloride conductance.
C) closed, reducing sodium conductance.
D) open, contributing to resting sodium conductance.
E) open, contributing to resting potassium conductance.

Question 24

The purine transmitters include

A) acetylcholine and adenosine.
B) VIP and LHRH.
C) epinephrine and norepinephrine.
D) adenosine and ATP.
E) ATP and adrenaline.

Question 25

ATP is a major neurotransmitter in the

A) sympathetic nervous system.
B) parasympathetic nervous system.
C) neuromuscular junction.
D) M-channel synapses.
E) adrenal medulla.

Question 26

P1 and P2 receptors are so named because they are

A) prevalent in the parasympathetic nervous system.
B) activated by purines.
C) activated by polypeptides.
D) responsive to pain.
E) located in the pituitary.

Question 27

Beta-blockers, which block the actions of norepinephrine on b-receptors, can be used medically to treat

A) the inability to sleep.
B) high blood pressure.
C) overeating.
D) depression.
E) lethargy.

Question 28

Regulation of blood pressure based on body position is accomplished using

A) stretch receptors in the carotid artery.
B) oxygen receptors in the brain.
C) activated by polypeptides.
D) responsive to pain.
E) only found in the peripheral nervous system.

Question 29

Excessive feeding _______; while starvation _______.

A) activates the hypothalamus; inhibits the hypothalamus
B) stimulates GnRH; stimulates LHRH
C) inhibits melatonin; stimulates melatonin
D) increases leptin; decreases leptin
E) releases GABA; releases norepinephrine

Question 30

The enteric nervous system

A) is a useful model system because it is very simple with only a few neurons.
B) consists almost entirely of sensory neurons.
C) consists almost entirely of motor neurons.
D) contains all known neurotransmitters.
E) is fully understood in the lobster but not yet in humans.

Question 31

The enteric nervous system is still not well understood because

A) scientists have only recently begun to study its function.
B) the human enteric nervous system does not resemble that of any other species.
C) it contains an extremely large number of densely interconnected neural circuits.
D) electrical recordings cannot be used on these neurons.
E) it uses a different set of neurotransmitters than those found elsewhere.

Question 32

The region of the brain that is closely involved in regulation of the autonomic nervous system is the

A) hippocampus.
B) hypothalamus.
C) amygdala.
D) cerebellum.
E) limbic system.

Question 33

The hypothalamus controls functions such as

A) body temperature, appetite, heart rate, and growth.
B) coordination of complex skeletal motor activity.
C) emotions and empathy.
D) language comprehension and production.
E) fear and aggression.

Question 34

Leptin is

A) the principle neurotransmitter of the enteric nervous system.
B) a hormone released by the pituitary gland.
C) a protein involved in the regulation of blood pressure.
D) a peptide secreted by adipose cells.
E) a hormone released by hypothalamic neurons.

Question 35

If leptin is experimentally increased in the hypothalamus, the expected result would have which effect?

A) An increase in food intake
B) A reduction in food intake
C) A reduction in energy expenditure
D) Loss of rhythmicity of circadian cycles
E) No effect since the hypothalamus is not responsive to leptin

Question 36

Communication from the hypothalamus to the pituitary occurs through

A) both hormone release and direct innervation by the hypothalamus.
B) release of melatonin by the hypothalamus.
C) purinergic transmission.
D) a sympathetic ganglion.
E) M-currents.

Question 37

One major mechanism by which the hypothalamus effects hormone secretion is releasing

A) Ach into the pituitary.
B) NE into the bloodstream.
C) melatonin into the SCN.
D) GnRH into the pituitary.
E) NE into the sympathetic ganglia.

Question 38

GnRH, or Gonadotropin-releasing hormone, is released by the

A) hypothalamus to act on the pituitary.
B) pituitary to act on the adrenal glands.
C) gonads to act on the hypothalamus.
D) hypothalamus to act on the gonads.
E) pituitary to act at locations all over the body.

Question 39

Circadian rhythms are regulated by the release of melatonin from the

A) pineal gland.
B) pituitary gland.
C) hypothalamus.
D) limbic system.
E) optic nerve.

Question 40

The function of the hormone melatonin in humans is to

A) induce sleep.
B) inhibit sleep.
C) regulate the sleep/wake cycle.
D) activate sympathetic activity.
E) coordinate reproductive behaviors.

Question 41

The structure in the brain that serves as an 'internal clock' for circadian rhythms is the

A) periaqueductal grey.
B) photo-optic ganglion.
C) hypothalamus.
D) pineal gland.
E) suprachiasmatic nucleus.

Question 42

The sensory input that entrains the day/night cycle come from the

A) specialized photoreceptive ganglion cells in the visual system.
B) rods in the retina.
C) pineal gland.
D) lateral geniculate nucleus.
E) paraventricular nucleus.

Question 43

Destruction of the Suprachiasmatic Nucleus (SCN) would be expected to result in

A) hyperarousal and high activity levels.
B) loss of circadian rhythms.
C) Increased appetite and weight gain.
D) difficulty regulating heart rate and blood pressure.
E) reduction in sexual activity.

Question 44

The PER protein is involved in the function of

A) maintaining circadian rhythms.
B) maintaining blood pressure.
C) regulating body weight.
D) opening M-channels.
E) hypothalamic regulation.

Question 45

If retinal rod and cone cells are inactivated

A) circadian rhythms are abolished.
B) circadian rhythm cycles become longer.
C) circadian rhythm cycles become shorter.
D) animals behave as though they are constantly in the "night," or dark, cycle.
E) circadian rhythms can still be entrained.

Question 46

The major transmitter in the rat SCN is

A) norepinephrine.
B) acetylcholine.
C) GABA.
D) ATP.
E) glutamate.

Question 47

The role of GABA in the rat SCN is to

A) open chloride channels.
B) close chloride channels.
C) open sodium channels.
D) open potassium channels.
E) close potassium channels.

Question 48

Ephedrine is a drug that is sometimes used to prevent low blood pressure. It is not safe for frequent use due to common side effects, including fast heart rate, anxiety, high blood pressure, and loss of appetite. Knowing these effects of ephedrine, develop a hypothesis about how this drug is likely to affect the autonomic nervous system.

Question 49

Explain how fast, direct transmission occurs in autonomic ganglia. Include the main neurotransmitter, receptor types, and effects on receptors.

Question 50

What is the functional effect on a neuron when an M-channel is opened?

Question 51

Muscarine is a deadly toxin found in some mushrooms, with symptoms including decreased heart rate, hypotension (low blood pressure), and diarrhea. Knowing that it acts as a muscarinic receptor agonist, make a prediction about the mechanism by which these effects occur.

Question 52

Give one example of a drug for treating a disease that was discovered through the study of the sympathetic nervous system.

Question 53

Compare the activity of the carotid sinus neurons, and the resulting effect on cardiovascular sympathetic outputs, when the body is in the vertical position and when it is in the horizontal position.

Question 54

Give three reasons why the enteric nervous system has been so difficult to fully understand.

Question 55

Give two examples of pathways by which the hypothalamus can stimulate hormone release.

Question 56

Describe the pathway by which leptin regulates body weight.

Question 57

How does the function of melatonin in humans compare with its function in other species?

Question 58

What is the chain of events leading to the release of melatonin?

Question 59

You have a friend who recently told you that they are too stressed with all of their schoolwork, and can't fall asleep at night. They have started taking melatonin supplements in the evening in order to help them go to sleep. How would you respond to your friend?

Question 60

Explain how GABA can serve sometimes as an excitatory, and sometimes an inhibitory, neurotransmitter in the SCN.

Question 61

Where are the sensory receptors that detect light/dark signals used to entrain circadian rhythms?

Question 62

Describe what you would expect to see if you were to apply bicuculline (a GABA antagonist) to a slice of rat SCN, and observe an extracellular recording for 24 hours.