Heart Flashcards
What are the components of the cardiovascular system?
Heart, blood vessels, blood
These components work together to circulate blood throughout the body.
Trace the movement of blood throughout the cardiovascular system.
From the heart to arteries, arterioles, capillaries, venules, veins, and back to the heart
This cycle ensures the delivery of oxygen and nutrients to tissues.
What is the size and shape of the heart?
Approximately the size of a fist, conical shape
The heart is located in the thoracic cavity, between the lungs.
Identify the layers of the pericardium.
Fibrous pericardium, serous pericardium
The serous pericardium has two layers: parietal and visceral.
What are the 3 layers of the heart wall?
Epicardium, myocardium, endocardium
Each layer has distinct functions and structures.
Identify key parts of the anatomy of the heart.
Atria, ventricles, valves, septa
These structures are crucial for the heart’s pumping action.
What is the flow of blood through the chambers of the heart?
Right atrium → right ventricle → lungs → left atrium → left ventricle
This flow is essential for oxygenation of blood.
What are key characteristics of cardiac muscle?
Striated, involuntary, interconnected
Cardiac muscle cells are connected by intercalated discs.
Define intercalated discs.
Specialized connections between cardiac muscle cells
They facilitate electrical conduction and mechanical coupling.
What are the properties of pacemaker cells?
Automaticity, rhythmicity
Pacemaker cells generate electrical impulses that initiate heartbeats.
Map the electrical activity of the heart.
SA node → AV node → Bundle of His → Purkinje fibers
This pathway coordinates heart contractions.
Differentiate between systole and diastole.
Systole: contraction phase; Diastole: relaxation phase
These phases are crucial for the cardiac cycle.
What is sinus rhythm?
Normal heartbeat initiated by the SA node
It indicates proper functioning of the heart’s electrical system.
What is nodal rhythm?
Heartbeat initiated by the AV node
This occurs when the SA node fails to function properly.
Define spontaneous depolarization.
The gradual increase in membrane potential until threshold is reached
This process is essential for pacemaker activity.
What is the purpose of ECG’s?
To measure and display the electrical activity of the heart
ECGs help diagnose various cardiac conditions.
Identify abnormal ECG readings.
Arrhythmias, ST elevation, QRS widening
These abnormalities can indicate serious heart issues.
Define cardiac cycle.
The sequence of events in one heartbeat
It includes all phases of heart contraction and relaxation.
What are key variables of fluid dynamics?
Pressure, flow, resistance
These variables influence blood circulation.
How is pressure measured in the cardiovascular system?
In mmHg using sphygmomanometers
Blood pressure is crucial for assessing cardiovascular health.
What are S1 and S2 heart sounds?
S1: closing of AV valves; S2: closing of SL valves
These sounds are used to assess cardiac function.
Identify phases of the cardiac cycle.
Atrial systole, ventricular systole, diastole
Each phase has distinct pressure and volume changes.
What is the Wiggers diagram?
A graphical representation of cardiac cycle events
It illustrates pressure changes, heart sounds, and ECG.
What do EDV, ESV, stroke volume, and ejection fraction represent?
EDV: End Diastolic Volume; ESV: End Systolic Volume; Stroke Volume: volume ejected per beat; Ejection Fraction: percentage of EDV ejected
These parameters assess heart efficiency.
Define congestive heart failure.
A condition where the heart cannot pump enough blood
It leads to fluid buildup in tissues.
What are cardiac centers?
Nuclei in the medulla oblongata regulating heart function
They control heart rate and rhythm.
Map the sympathetic and parasympathetic pathways.
Sympathetic: increases heart rate; Parasympathetic: decreases heart rate
These pathways balance heart function.
What is the role of innervating nodal cells vs muscle?
Nodal cells: regulate heart rhythm; Muscle: contract for pumping
This distinction is crucial for heart function.
What components affect cardiac output?
Heart rate, stroke volume
Cardiac output is the product of these two variables.
What are positive and negative chronotropic agents?
Positive: increase heart rate; Negative: decrease heart rate
These agents include hormones and neural influences.
Define bradycardia.
Abnormally slow heart rate, typically below 60 bpm
It can indicate cardiac issues or be a normal finding in athletes.
Define tachycardia.
Abnormally fast heart rate, typically above 100 bpm
It can result from stress, exercise, or pathology.
What are inotropic agents?
Substances that affect the force of heart contractions
Examples include positive inotropes like digoxin and negative inotropes.
How does exercise affect cardiac output?
Increases cardiac output to supply more oxygen to muscles
This is due to increased heart rate and stroke volume.
Differentiate between the 3 categories of vessels.
Arteries, veins, capillaries
Each category has distinct structures and functions in circulation.
What are the different layers of blood vessels?
Tunica intima, tunica media, tunica externa
These layers vary in thickness and composition among vessel types.
What are the types of vessels?
Arteries, veins, capillaries, arterioles, venules
Each type plays a specific role in circulation.
What mechanisms are involved in venous return?
Muscle pump, respiratory pump, venous valves
These mechanisms help return blood to the heart.
Define circulatory shock.
A condition where blood flow is insufficient to meet tissue needs
It can lead to organ failure and requires immediate treatment.
Explain the relationship between blood pressure, resistance, and flow.
Blood flow = blood pressure / resistance
This relationship is fundamental in understanding cardiovascular dynamics.
How is blood pressure measured and expressed?
Measured in mmHg using sphygmomanometers
Blood pressure readings consist of systolic and diastolic values.
How is pulse pressure calculated?
Pulse pressure = systolic pressure - diastolic pressure
It provides insight into cardiovascular health.
What influences vessel diameter?
Local, neural, and hormonal factors
Changes in diameter affect blood flow and pressure.
