Electrical Anatomy of the Heart

Which of the following is true regarding the Bundle of His? A) The impulse is slowed to allow for atrial contraction. B) The impulse is slowed to allow for ventricular filling. C) Important because it is the route of communication between the atria and the ventricles. D) Stimulates the release acetylcholine.

C) Important because it is the route of communication between the atria and the ventricles.

Which of the following is an ion found in high concentrations outside a polarized cardiac cell? A) Potassium B) Sulfates C) Phosphates D) Sodium

D) Sodium

Which of the following statements is INCORRECT regarding the electrical anatomy of the heart? A) The internodal pathways connect the SA node to the right ventricle. B) The internodal pathways connect the SA node and the AV node. C) The SA node is located in the right atrium. D) The SA node is inferior to the superior vena cava.

D) The SA node is inferior to the superior vena cava

Which of the following is correct regarding relative refractory period? A) Defined as the time when the cell cannot respond to another stimulus. B) Defined as the time when the cell can respond to another stimulus but is not resting. C) Also known as the resting period. D) The time when the cell response is increased to allow transmission of the impulse through the network.

B) Defined as the time when the cell can respond to another stimulus but is not resting.

Which of the following is the correct intrinsic rate for the AV node? A) 60-100 bpm B) 40-60 bpm C) 60 - 80 bpm D) 20-40 bpm

B) 40-60 bpm

Which of the following is true regarding the trigger zone? A) The impulse is slowed to allow for atrial contraction. B) Made of autonomic fibers. C) Important because this is where the electrical signal speeds up again. D) Known as the core of the AV node.

C) Important because this is where the electrical signal speeds up again.

Which of the following is INCORRECT regarding the Purkinje Fibers? A) Right Bundle Branch terminates at the Purkinje fibers. B) Left Anterior Fascicle terminates at the Purkinje fibers. C) Left Posterior Fascicle terminates at the Purkinje fibers. D) Left Bundle Branch terminates at the Purkinje fibers.

D) Left Bundle Branch terminates at the Purkinje fibers.

Which of the following is INCORRECT regarding the transition zone of the AV node? A) Located on the tip of the AV node. B) Composed of autonomic fibers. C) Very arrhythmogenic. D) Located in between the compact zone and the trigger zone.

D) Located in between the compact zone and the trigger zone.

Which of the following is not an ion found in high concentrations inside a polarized cardiac cell? A) Potassium B) Sulfates C) Phosphates D) Magnesium

D) Magnesium

The left bundle branch bifurcates into which of the following? A) Right bundle branch and the Purkinje fibers. B) Left Posterior Fascicle and the Purkinje fibers. C) Left Anterior Descending and the Left Anterior Fascicle D) Left Posterior Fascicle and Left Anterior Fascicle

D)Left Posterior Fascicle and Left Anterior Fascicle

Which of the following is true regarding depolarization of a cell? A) During Phase 0 fast sodium channels open and sodium rushes inside the cell. B) During Phase 0 fast sodium channels open and sodium rushes outside of the cell. C) During Phase 0 fast magnesium channels open and push sodium out of the cell so that magnesium can rush in. D) During Phase 0 fast potassium channels open and potassium rushes inside of the cell.

A) During Phase 0 fast sodium channels open and sodium rushes inside the cell

Which of the following is CORRECT regarding the compact zone? A) Histologically similar to the SA node. B) Releases acetylcholine. C) Stimulates norepinephrine. D) Histologically similar to the Purkinje fibers.

A) Histologically similar to the SA node.

How many different phases are there in an action potential? A) 3 B) 4 C) 6 D) 5

5

Which of the following is the correct intrinsic rate for the Purkinje Network? A) 20-40 bpm B) 60-80 bpm C) 40-60 bpm D) 60-100 bpm

A) 20-40 bpm

Which of the following statements is NOT true? A) All cardiac cells have the same threshold. B) All cardiac cells do not have the same threshold. C) If a cardiac cell reaches threshold it will depolarize. D) Action potential is based on sodium and calcium levels outside of the cell and potassium levels inside of the cell.

A) All cardiac cells have the same threshold.

Which of the following ions slowly enters the cell during Phase 2 of action potential? A) Calcium B) Potassium C) Sodium D) Magnesium

A) Calcium

Which of the following is the primary ion required for muscular contraction? A) Calcium B) Sodium C) Potassium D) Magnesium

A) Calcium

Which of the following is true regarding Phase 3 of action potential? A) Calcium channels close. B) Calcium channels open. C) Potassium channels close. D) Sodium channels open.

A) Calcium channels close.

What is the correct ratio of sodium ions to potassium ions transferred in the sodium - potassium pump? A) 3:2 B) 4:6 C) 2:1 D) 6:10

3:2

Which of the following statements is true? A) It is harder to have a posterior fascicular block than it is to have an anterior fascicular block. B) The Left Bundle Branch is longer than the Right Bundle Branch. C) It is harder to have an anterior fascicular block than it is to have a posterior fascicular block. D) The Right Bundle Branch is shorter than the Left Bundle Branch.

A) It is harder to have a posterior fascicular block than it is to have an anterior fascicular block.

Which of the following is INCORRECT regarding the anterior-superior inter nodal tract? A) Known as the slow tract. B) Located in the right atrium. C) Connect the SA and the AV nodes. D) Known as the fast tract.

A) Known as the slow tract

Which of the following is true regarding a cardiac cell in a state of rest? A) Outside of the cell is positive and the inside of the cell is negative. B) Outside of the cell is negative and the inside of the cell is positive. C) Outside of the cell is neutral and the inside of the cell is negative. D) Outside of the cell is neutral and the inside of the cell is positive.

A) Outside of the cell is positive and the inside of the cell is negative

Which of the following is the correct definition for action potential? A) The change in the electrical charge of the cardiac cell. B) The influx of magnesium into the cardiac cell. C) The influx of phosphates into the cell during depolarization. D) The displacement of magnesium from inside the cardiac cell to outside the cardiac cell.

A) The change in the electrical charge of the cardiac cell

Which of the following is the correct reason that the electrical impulse is slowed in the compact zone? A) The impulse is slowed to allow for atrial contraction. B) The impulse is slowed to allow for ventricular contraction. C) The impulse is slowed to allow for atrial filling. D) The impulse is slowed to allow for ventricular filling.

A) The impulse is slowed to allow for atrial contraction.

Which of the following is the correct definition for absolute refractory period? A) The time when the cell cannot respond to another stimulus. B) The time when cell response to a stimulus is slowed to allow contraction of the ventricles. C) The time when the cell response is increased to allow transmission of the impulse through the network. D) The time when the cell rebounds the impulse transmission between other cardiac cells.

A) The time when the cell cannot respond to another stimulus

Which of the following is correct regarding the right bundle branch? A) Is a bifurcation of the Bundle of His and terminates at the Purkinje fibers. B) Is a bifurcation of the Left Anterior Fascicle and the Left Posterior Fascicle and terminates at the Purkinje fibers. C) Is a bifurcation of the Left Anterior Descending and terminates at the Left Anterior Fascicle and the Left Posterior Fascicle. D) Is a bifurcation of Right Anterior Descending and terminates at the Right Anterior Fascicle.

A)Is a bifurcation of the Bundle of His and terminates at the Purkinje fibers.

The correct term for the ability to receive an impulse and transmit it to another cell is:

Conductivity

Which of the following is INCORRECT about the conductive pathway of the heart? A) Does not have contractility properties. B) Does not contain myofibrils. C) Increased number of gap junctions. D) Contractility is the major property which helps speed up transmission of electrical impulses.

D) Contractility is the major property which helps speed up transmission of electrical impulses

Which of the following is NOT a property that allows the heart to generate and conduct electricity? A) Automaticity B) Excitability C) Conductivity D) Elasticity

D) Elasticity

During what phase can the relative refractory period occur? A) Phase 0 B) Phase 3 C) Phase 2 D) Phase 1

Phase 3