Cardiovascular Physiology Overview

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Questions and Answers

What does auscultation of the apical pulse primarily help to assess?

The strength of peripheral pulses

The functionality of the stethoscope

The rhythm and rate of the pulse (correct)

The presence of pulse points on the body

Which pulse abnormality is characterized by a slow pulse rate below 60 beats per minute in adults?

Ventricular Tachycardia

Bradycardia (correct)

Tachycardia

Atrial Fibrillation

Which of the following pulse points can be palpated at the wrist?

Carotid

Radial (correct)

Brachial

Femoral

What distinguishes Pulsus Trigeminus in terms of heartbeats?

Two normal sinus beats alternating with a weak beat Signup and view all the answers

Which part of the stethoscope is primarily used to amplify sounds from the body for auscultation?

Diaphragm Signup and view all the answers

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

It generates electrical impulses for heartbeats. Signup and view all the answers

What is the stroke volume (SV) typically ejected by the heart per beat?

70 ml Signup and view all the answers

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

The heart rate decreases. Signup and view all the answers

Which of the following characteristics is NOT used to assess pulse?

Color Signup and view all the answers

Which system primarily slows down the heart rate in response to increased blood volume?

Parasympathetic nervous system Signup and view all the answers

How does cardiac output (CO) relate to stroke volume (SV) and heart rate (HR)?

CO equals SV multiplied by HR. Signup and view all the answers

What physiological control is exerted by the cardiac centers in the medulla?

They modulate heart rate based on sensory impulses. Signup and view all the answers

Which factor is likely to cause a higher pulse rate in individuals?

Female sex Signup and view all the answers

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

Increases pulse rate Signup and view all the answers

Which factor is most likely to decrease pulse rate?

Digitalis (lanoxin) Signup and view all the answers

What is indicated by a pulse deficit?

An insufficient heart contraction that fails to transmit a pulse wave Signup and view all the answers

How does stress affect pulse rate?

Increases pulse rate due to sympathetic stimulation Signup and view all the answers

Which statement about pulse strength is accurate?

Normal pulse strength is consistent with each heartbeat Signup and view all the answers

What role do pulmonary conditions play in pulse rate?

Increase pulse rate due to poor oxygenation Signup and view all the answers

What is true about pulse rhythm?

Regular rhythm means equal time intervals betweenbeats Signup and view all the answers

What happens to the pulse rate when changing from a lying down position to standing?

It increases Signup and view all the answers

Study Notes

Pulse

The stimulus for heart conduction starts as an electrical impulse in the sinoatrial (SA) node of the right atrium.
In adults, the SA node initiates the impulse 60-100 times per minute.
The impulse quickly spreads through the conduction system to the rest of the heart, causing synchronous muscle fiber contractions.
Pulse is the wave of blood forced through arteries by left ventricle contraction.
Pulse is created by alternating expansion and recoil of arteries during each cardiac cycle.

Physiology and Regulation

Blood flows continuously through the body.
Cardiac centers (medulla of the brain stem) control the heart through sympathetic and parasympathetic pathways.
Cardiac centers adjust heart rate based on sensory input, such as aortic arch stretch (blood volume).
Increased blood volume leads to a reflex decrease in heart rate (parasympathetic).

Cardiac Output (CO) and Stroke Volume (SV)

Cardiac output (CO) is the amount of blood pumped by the ventricles per minute.
Stroke volume (SV) is the amount of blood ejected per heartbeat (typically 70 mL).
CO = SV x Heart Rate (HR)
Blood volume increase increases heart rate.
Blood volume decrease decreases heart rate.
The heart maintains a relatively constant circulatory blood flow (approximately 70-72 mL of blood entering the aorta per ventricular contraction).
Pulse wave travels rapidly through the arteries, palpable at peripheral arteries.

Characteristics of Pulse

Pulse characteristics include rate, rhythm, and volume/strength.
Rate: Number of pulsations per minute.
Factors influencing pulse rate include:
- Age
- Sex (slightly higher in females until menopause)
- Exercise/muscular activity (increases rate), rest/sleep (decreases rate)
- Temperature (increases with elevation)
Rhythm: Time intervals between pulses; normally regular. Irregularity (arrhythmia) can indicate problems.
- Arrhythmias: Result from early, late or missed beats
- Pulse deficit is the difference between apical and radial pulse rates, indicating an inefficient contraction of the heart.

Factors Affecting Pulse Rate

Stress and emotions increase sympathetic stimulation, increasing heart rate.
Medications:
- Positive chronotropics (e.g., atropine) elevate pulse rate.
- Negative chronotropics (e.g., digitalis) decrease pulse rate.
Hemorrhage leads to increased sympathetic stimulation and pulse rate.
Position changes (standing/sitting) result in higher pulse rates.
Pulmonary conditions (poor oxygenation) increase pulse rate.
Various diseases (e.g., infection, thyrotoxicosis, anemia) can impact pulse rate.

Pulse Volume/Strength

Pulse strength reflects blood volume against arterial walls and vascular system condition.
Normally, pulse strength remains consistent with each beat.
Strength graded as: normal, thready, weak, or bounding.
A weak pulse is difficult to palpate and lose during palpation.
A normal pulse is easily palpable and not easily obliterated.
A strong/bounding pulse is easily palpated and difficult to obliterate.

Methods for Pulse Assessment

Palpation: Use fingertips to locate strongest pulse, count rate, evaluate rhythm, and assess volume.
Auscultation: Use a stethoscope to assess apical pulse (more accurate for irregular rhythms or difficult peripheral palpation).

Stethoscope Parts

The stethoscope has earpieces, a binaural spring, tubing, a stem, and a chest piece (with bell and diaphragm).

Pulse Sites

Illustration/diagram shows various pulse points, such as carotid, brachial, radial, femoral, popliteal, dorsalis pedis, etc.

Abnormalities of Pulse

Tachycardia: Abnormally high pulse rate (>100 bpm in adults).
Bradycardia: Abnormally low pulse rate (<60 bpm in adults).
Pulsus bigeminus (bigeminy): Premature beat (weak) alternates with normal sinus beat (strong).
Pulsus trigeminus (trigeminy): Premature beat alternates with two normal sinus beats.
Ventricular Tachycardia: Weak pulse with rate of 150-250 bpm; caused by impulses originating from an area of the ventricles, not the SA node.
Atrial Fibrillation: Irregular, weak pulse with pulse deficit. Impulses are discharged irregularly from different areas of the atria that don't coordinate with the AV node and bundle of His; cannot transmit high atrial excitation rate.

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Description

This quiz covers essential concepts in cardiovascular physiology, including the electrical conduction system of the heart, the role of the sinoatrial node, and mechanisms regulating heart rate. It delves into cardiac output and stroke volume, helping you understand the dynamics of blood flow and heart function. Test your knowledge on how these elements work together to maintain proper circulatory health.