BIOS 251 EXAM 3 QUESTIONS AND ANSWERS
2024 EDITION
◉ Regulation of the heart (or any organ or tissue) by neural input,
circulating hormones, or any other factor originating from outside
the organ is referred to as ________ control.
A) intrinsic
B) neurogenic
C) extrinsic
D) voluntary
E) myogenic. Answer: C
◉ Which of the following structures is poorly innervated by the
parasympathetic nervous system and, therefore, an increase in
parasympathetic activity has little effect on this structure?
A) ventricles
B) conduction pathway
C) sinoatrial node
D) Purkinje fibers
E) atrioventricular node. Answer: A
◉ The SA node is innervated by the
,A) sympathetic nervous system only.
B) somatic nervous system only.
C) parasympathetic nervous system only.
D) sympathetic and parasympathetic nervous systems.
E) sympathetic, parasympathetic, and somatic nervous systems..
Answer: D
◉ Which of the following is an effect of parasympathetic activity to
the heart?
A) The rate of spontaneous depolarization in SA nodal cells
decreases.
B) SA nodal cells are depolarized.
C) Heart rate is increased.
D) cAMP is activated.
E) Postganglionic neurons release acetylcholine, which binds to
nicotinic cholinergic receptors in
the SA node.. Answer: A
◉ Which of the following is a FALSE statement about sympathetic
activity to the SA node?
A) Norepinephrine binds to beta1 adrenergic receptors.
B) Potassium channel closing is enhanced.
C) cAMP levels in the pacemaker cells increases.
, D) Funny channel opening is enhanced.
E) The rate of spontaneous depolarization is increased.. Answer: B
◉ Under resting conditions, heart rate is primarily under the control
of what control system?
A) the parasympathetic nervous system
B) the somatic nervous system
C) the sympathetic nervous system
D) intrinsic mechanisms
E) epinephrine. Answer: A
◉ An increase in heart rate can be mediated through which of the
following?
A) a decrease in parasympathetic nervous activity only
B) a decrease in sympathetic activity only
C) an increase in sympathetic activity only
D) an increase in parasympathetic activity and a decrease in
sympathetic activity
E) a decrease in parasympathetic activity and an increase in
sympathetic activity. Answer: E
◉ Which of the following would NOT result from an increase in
ventricular contractility?
2024 EDITION
◉ Regulation of the heart (or any organ or tissue) by neural input,
circulating hormones, or any other factor originating from outside
the organ is referred to as ________ control.
A) intrinsic
B) neurogenic
C) extrinsic
D) voluntary
E) myogenic. Answer: C
◉ Which of the following structures is poorly innervated by the
parasympathetic nervous system and, therefore, an increase in
parasympathetic activity has little effect on this structure?
A) ventricles
B) conduction pathway
C) sinoatrial node
D) Purkinje fibers
E) atrioventricular node. Answer: A
◉ The SA node is innervated by the
,A) sympathetic nervous system only.
B) somatic nervous system only.
C) parasympathetic nervous system only.
D) sympathetic and parasympathetic nervous systems.
E) sympathetic, parasympathetic, and somatic nervous systems..
Answer: D
◉ Which of the following is an effect of parasympathetic activity to
the heart?
A) The rate of spontaneous depolarization in SA nodal cells
decreases.
B) SA nodal cells are depolarized.
C) Heart rate is increased.
D) cAMP is activated.
E) Postganglionic neurons release acetylcholine, which binds to
nicotinic cholinergic receptors in
the SA node.. Answer: A
◉ Which of the following is a FALSE statement about sympathetic
activity to the SA node?
A) Norepinephrine binds to beta1 adrenergic receptors.
B) Potassium channel closing is enhanced.
C) cAMP levels in the pacemaker cells increases.
, D) Funny channel opening is enhanced.
E) The rate of spontaneous depolarization is increased.. Answer: B
◉ Under resting conditions, heart rate is primarily under the control
of what control system?
A) the parasympathetic nervous system
B) the somatic nervous system
C) the sympathetic nervous system
D) intrinsic mechanisms
E) epinephrine. Answer: A
◉ An increase in heart rate can be mediated through which of the
following?
A) a decrease in parasympathetic nervous activity only
B) a decrease in sympathetic activity only
C) an increase in sympathetic activity only
D) an increase in parasympathetic activity and a decrease in
sympathetic activity
E) a decrease in parasympathetic activity and an increase in
sympathetic activity. Answer: E
◉ Which of the following would NOT result from an increase in
ventricular contractility?
