Pulse and Heart Function Basics

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the main advantage of auscultating the apical pulse with a stethoscope?

It can detect temperature changes.

It is quicker than peripheral pulse measurement.

It provides the most accurate assessment of pulse rate. (correct)

It eliminates the need for regular training.

Which description best fits tachycardia?

A pulsation pattern with alternating weak and strong beats.

An irregular pulse that is weak and difficult to detect.

An elevated pulse rate above 100 beats per minute. (correct)

A slow pulse rate below 60 beats per minute.

What distinguishes ventricular tachycardia from other pulse abnormalities?

It is identified by alternating normal and premature beats.

It features weak pulses with a rate between 150-250 beats per minute. (correct)

It is marked by a pulse that is very strong and regular.

It has a heart rate of less than 60 beats per minute.

Which pulse sites are typically assessed for cardiovascular evaluations?

Carotid, brachial, radial, and dorsalis pedis. Signup and view all the answers

In what scenario is using the stethoscope's diaphragm most beneficial?

To measure the pulse rate accurately during arrhythmias. Signup and view all the answers

What is the primary function of the sinoatrial (SA) node in the heart?

To initiate the electrical impulse for heart conduction Signup and view all the answers

Which of the following statements about blood flow and the cardiac cycle is correct?

Pulse waves are created by alternating expansion and recoil of arteries Signup and view all the answers

How is cardiac output (CO) calculated?

CO = SV x HR Signup and view all the answers

Which factor is NOT mentioned as affecting pulse rate?

Physical Activity Level Signup and view all the answers

What happens to the heart rate when there is an increase in blood volume?

Heart rate decreases reflexively Signup and view all the answers

What is the normal stroke volume (SV) of blood ejected by the heart per beat?

70 ml Signup and view all the answers

How does the pulse rate typically differ between males and females?

Females have a higher pulse rate due to greater nervous system activity Signup and view all the answers

Which characteristic of pulse is determined by the number of pulsations felt over an artery per minute?

Rate Signup and view all the answers

What effect does prolonged application of heat have on pulse rate?

Increases the pulse rate Signup and view all the answers

Which of the following factors can lead to a decrease in pulse rate?

Digitalis (lanoxin) Signup and view all the answers

Which condition is most likely to cause an increase in pulse rate due to sympathetic stimulation?

Hemorrhage Signup and view all the answers

What does a pulse deficit indicate when assessed?

Inefficient heart contraction Signup and view all the answers

How is pulse rhythm defined?

The time intervals between each pulse beat Signup and view all the answers

In which position is the pulse rate typically higher?

Standing or sitting Signup and view all the answers

What might an irregular pulse rhythm signify?

Arrhythmia or dysrhythmia Signup and view all the answers

What is the best method to assess the pulse rate accurately?

Palpating with the tips of the middle three fingers Signup and view all the answers

Study Notes

Pulse

Pulse is the wave of blood forced through arteries by left ventricle contraction.
Alternating expansion and recoil of arteries during each cardiac cycle creates the pulse wave.

Introduction

The heart's conduction begins with an electrical impulse in the sinoatrial (SA) node of the right atrium.
In adults, the SA node initiates electrical impulses 60-100 times per minute.
This impulse quickly travels through the conduction system, causing heart muscle fibers to contract synchronously.

Pulse Definitions

Waves of blood: Blood forced through arteries by left ventricle contraction.
Arterial expansion/recoil: Blood waves created by alternating expansion and recoil of arteries during the cardiac cycle.

Physiology and Regulation

Blood circulates continuously, controlled by cardiac centers in the medulla of the brain stem.
Sympathetic or parasympathetic systems regulate heart rate.
Sensory impulses from the heart (e.g., aortic arch stretch from increased blood volume) trigger a reflex slowing of heart rate via the parasympathetic nervous system.

Cardiac Output

Stroke volume (SV): Amount of blood ejected per heartbeat (70 ml).
Cardiac output (CO): Amount of blood pushed by ventricles per minute (CO = SV x Heart Rate).
Increased blood volume tends to decrease heart rate.
Decreased blood volume will increase heart rate.
Normal circulatory blood flow is approximately 70-72ml of blood entering the aorta with each ventricular contraction.
The aorta expands with each ejection, creating a pulse wave that travels to peripheral arteries for palpation.

Pulse Characteristics

Rate: Number of pulsations felt over an artery per minute.
Rhythm: Time intervals between pulse beats.
- Regular rhythm: Equal intervals between beats
- Irregular rhythm: Interrupted intervals or early/late/missing beats (arrhythmia/dysrhythmia).
Volume/Amplitude/Strength: Reflects blood ejected, blood's force against arterial walls, and vascular condition.
- Pulse strength is graded as normal, thready, weak, or bounding.

Factors Affecting Pulse Rate

Age: Female pulse rate slightly higher than male pre-menopause.
Sex: Females (pre-menopause) tend to have slightly higher pulse rates than males.
Exercise/Muscular Activity: Exercise increases pulse rate; rest and sleep decrease it.
Temperature: Pulse rate increases about 10 beats per minute with each degree of temperature elevation.
Stress/Emotions: Stress increases sympathetic stimulation, increasing heart rate.
Medications: Positive chronotropics (e.g., atropine) increase pulse rate; negative chronotropics (e.g., digitalis) decrease it.
Hemorrhage: Blood loss increases sympathetic stimulation and pulse rate.
Position Changes: Standing/sitting pulse rate higher than lying down.
Pulmonary Conditions: Conditions affecting oxygenation increase pulse rate.
Disease Conditions: Many diseases can alter pulse rate (some increase; some decrease).

Pulse Deficit

An inefficient heart contraction disrupting pulse transmission generates a pulse deficit.
This deficit is assessed by comparing apical and radial pulse rates to see the difference.

Pulse Assessment Methods

Palpation: Using the tip of the middle fingers to feel for pulse rate, rhythm, and volume.
Auscultation: Using a stethoscope to listen to the apical pulse (most accurate for irregular rhythms or difficult peripheral pulses).

Stethoscope Parts

The stethoscope has four major parts: earpieces, binaural spring, tubing, and chest piece (which includes bell and diaphragm).

Pulse Sites

Diagram showing various pulse sites on the body.

Pulse Abnormalities

Tachycardia: Abnormally elevated pulse rate (over 100 beats per minute in adults).
Bradycardia: Abnormally slow pulse rate (below 60 beats per minute in adults).
Pulsus Bigeminus: Premature (weak) beat with a normal beat.
Pulsus Trigeminus: Premature beat with two normal beats.
Ventricular Tachycardia: Weak, rapid pulse (150-250 bpm), originating from a hyper-excitable ventricular focus.
Atrial Fibrillation: Irregular, weak pulse with a pulse deficit, originating from rapid multiple atrial firing.

Studying That Suits You

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

Description

This quiz explores the fundamentals of pulse and heart physiology. It covers the mechanics of blood flow, the role of the sinoatrial node, and the regulatory systems governing heart rate. Test your knowledge on how these elements work together to maintain circulation.