Cardiac Anatomy, Electrophysiology & Hemodynamic Foundations

A comprehensive set of vocabulary flashcards covering cardiac anatomy, the electrical conduction system, hemodynamic measurements, and monitoring techniques based on the lecture material.

Mediastinum

The location in the thoracic cavity between the pleural cavities where the heart is situated, behind and slightly on the left side of the sternum.

Apex

The blunt rounded part of the heart.

Base

The flat part at the opposite end of the apex of the heart.

Automaticity

The ability of a cardiac cell to generate an electrical impulse independently, without involving the nervous system.

Excitability

The property of a cardiac cell that allows it to respond to electrical stimulation.

Conductivity

The ability of a cardiac cell to pass or propagate electrical impulses from cell to cell.

Contractility

The ability of a cardiac cell to shorten its length in response to electrical stimulation.

Fibrous pericardium

The outer layer of the pericardial sac made of tough, fibrous connective tissue that anchors the heart to the mediastinum.

Serous pericardium

The inner layer of the pericardial sac composed of thin flat epithelial cells, divided into the parietal and visceral layers.

Parietal pericardium

The layer of the serous pericardium that lines the fibrous pericardium.

Visceral pericardium (Epicardium)

The layer of the serous pericardium that lines the heart surface.

Pericardial cavity

The space between the parietal and visceral pericardium filled with pericardial fluid to reduce friction.

Myocardium

The middle layer of the heart consisting of heart muscle.

Endocardium

The innermost layer of the heart.

Interatrial septum

The wall that separates the right and left atria.

Interventricular septum

The wall that separates the right and left ventricles.

Tricuspid valve

The atrioventricular valve located between the right atrium and right ventricle.

Bicuspid (Mitral) valve

The atrioventricular valve located between the left atrium and left ventricle.

Systole

The contraction phase of the heart muscle; when used alone, it refers to ventricular contraction.

Diastole

The relaxation phase of the heart muscle; when used alone, it refers to ventricular relaxation.

Sinoatrial (SA) node

Known as the dominant pacemaker of the heart, located in the upper right atrium with an intrinsic rate of $60-100\,\text{bpm}$.

Atrioventricular (AV) node

Part of the AV junctional tissue that slows conduction to create a delay before impulses reach the ventricles, with an intrinsic rate of $40-60\,\text{bpm}$.

Purkinje system

A network of fibers that spreads impulses rapidly throughout the ventricular walls, with an intrinsic rate of $20-40\,\text{bpm}$.

Depolarization

An electrical process where the active charge of a cell is altered by a shift of electrolytes, stimulating muscle fiber contraction.

Repolarization

An electrical process where chemical pumps re-establish an internal negative charge as cells return to their resting state.

Cardiac Output (CO)

The amount of blood pumped by the ventricles in one minute, calculated as $CO = \text{stroke volume} \times \text{heart rate}$. Normal at rest is $5-8\,\text{L/min}$.

Frank-Starling Mechanism

The principle that the heart pumps what it receives; stretching the cardiac muscle during diastolic loading leads to more forceful contraction and increased stroke volume.

Mean Arterial Pressure (MAP)

The average blood pressure during a single cardiac cycle, often considered the perfusion pressure for organs. Formula: $MAP = 1/3\,\text{systolic pressure} + 2/3\,\text{diastolic pressure}$.

Pulse Pressure

The change in blood pressure during contraction, calculated as $\text{Systolic BP} - \text{Diastolic BP}$. Normal resting value is $40\,\text{mmHg}$.

Stroke Volume (SV)

The amount of blood pumped by the heart in one contraction, calculated as $SV = EDV - ESV$. The average is approximately $70\,\text{mL}$.

Ejection Fraction (EF)

The percentage of total ventricular volume ejected with each beat; calculated as $EF = \frac{\text{Stroke Volume}}{\text{Total Volume}} \times 100$. Normal is $50\%\text{ to }70\%$.Ratio.

Preload

The amount of blood in the ventricle before it contracts, related to the 'filling pressures' or the 'pre-stretch' of the muscle fibers.

Afterload

The pressure the ventricles must generate to overcome the pressure in the aorta to eject blood into the circulation.

Chronotropy

A term used to describe heart rate.

Inotropism

A term used to describe the force and velocity of ventricular ejection (contractility).

Central Venous Pressure (CVP)

The pressure recorded from the right atrium or superior vena cava, representing right heart preload and RV end-diastolic pressure. Normal is $2-6\,\text{mmHg}$.

Pulmonary Capillary Wedge Pressure (PCWP)

An indirect measurement of left heart preload and left ventricular end-diastolic pressure, obtained by inflating a balloon in the pulmonary artery. Normal is $8-12\,\text{mmHg}$.