Recent Lessons

Show all results for ""

Feature Overview

Ace your exams with our all-in-one platform for creating and sharing quizzes and tests.

Quizzes

Create quizzes and tests automatically from your content using AI.

Flashcards

Automatically turn your notes into digital flashcards.

Share, Export & Embed

Share with classmates or export to Excel and your learning management system.

Stats & Reporting

Auto-grading quizzes and tests with detailed stats and reports.

Mobile Apps

The smarter way to study – wherever you are.

Pricing

Search...

10 Questions

5 Views

Cardiac Pacemaker Properties Quiz

Choose a study mode

Play Quiz

Study Flashcards

Spaced Repetition

Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the property of self-excitation of the heart called?

Automaticity (correct)

Depolarization

Rhythmicity

Autorhythmicity

Which part of the heart exhibits the highest Rhythmicity?

Bundle of His

Atrioventricular Node (AVN)

Purkinje fibers

Sinoatrial Node (SAN) (correct)

What is the normal resting membrane potential (RMP) of the Sinoatrial Node (SAN)?

-70 to -75 mV

-90 mV

-55 to -60 mV (correct)

-40 to -45 mV

What causes the gradual depolarization in the mechanism of autorhythmicity?

Decrease in K+ efflux after each impulse Signup and view all the answers

What characterizes the upstroke depolarization in the rest of the heart muscle?

Rapid due to increased Na+ influx through Voltage gated channels Signup and view all the answers

What is the normal resting membrane potential (RMP) of the rest of the heart muscle?

-90mV Signup and view all the answers

What characterizes the upstroke depolarization in the Sinoatrial Node (SAN)?

Slow due to Ca++ influx Signup and view all the answers

What happens to the heart rate when the Sinoatrial Node (SAN) is cooled?

Decreases Signup and view all the answers

What is responsible for the property of self-excitation of the heart?

< myogenic not Nervous > Signup and view all the answers

What is the highest Rhythmicity exhibited by in the heart?

Sinoatrial Node (SAN) Signup and view all the answers

Study Notes

Heart Physiology

The property of self-excitation of the heart is called autorhythmicity.

Rhythmicity in the Heart

The sinoatrial node (SAN) exhibits the highest rhythmicity in the heart.

Membrane Potential

The normal resting membrane potential (RMP) of the sinoatrial node (SAN) is -60mV to -70mV.
The normal resting membrane potential (RMP) of the rest of the heart muscle is -90mV.

Mechanism of Autorhythmicity

The gradual depolarization in the mechanism of autorhythmicity is caused by the inward leak of sodium ions and the outward leak of potassium ions.

Upstroke Depolarization

The upstroke depolarization in the rest of the heart muscle is characterized by the rapid influx of sodium ions.
The upstroke depolarization in the sinoatrial node (SAN) is characterized by the rapid influx of calcium ions.

Response to Cooling

When the sinoatrial node (SAN) is cooled, the heart rate slows down.

Autorhythmicity

The sinoatrial node (SAN) is responsible for the property of self-excitation of the heart, also known as autorhythmicity.
The sinoatrial node (SAN) exhibits the highest rhythmicity in the heart.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Test your knowledge of the properties of the cardiac pacemaker, including automaticity, rhythmicity, and the role of the sinoatrial node (SAN) in heart function.