Chapter 15 A+P Word Bank

Action Potential

Electrical signal that triggers muscle contraction in the heart.

Key Ions

Sodium (Na⁺), Potassium (K⁺), Calcium (Ca²⁺) involved in heart action potentials.

Anterior Interventricular Artery

Major branch of the left coronary artery that supplies blood to the interventricular septum and anterior walls of both ventricles.

Aorta

Largest artery in the body, carries oxygenated blood from the left ventricle to the body.

Aortic Valve

Prevents backflow of blood from the aorta into the left ventricle.

Arteries

Blood vessels that carry blood away from the heart.

Arterioles

Small arteries that control blood flow to capillaries.

A-V Node

Delays the electrical impulse, allowing the atria to contract before the ventricles.

Capillaries

Smallest blood vessels where gas and nutrient exchange occurs.

Capillary Networks

Dense web of capillaries that connect arteries and veins in tissues.

Cardiac Anatomy

Includes chambers, valves, blood vessels, conduction system, and muscle layers of the heart.

Cardiac Cycle

Sequence of events in one heartbeat.

Phases of Cardiac Cycle

Atrial systole → Ventricular systole → Diastole.

Cardiac Depolarization

Electrical charge change that triggers heart contraction.

Cardiac Output Equation

CO = HR × SV (Heart Rate × Stroke Volume).

Cerebellum

Brain region that coordinates voluntary movements.

Chordae Tendineae

Fibrous strings that anchor heart valves to papillary muscles.

Coronary Sinus

Large vein that collects blood from the heart muscle and returns it to the right atrium.

Corpus Callosum

Structure in the brain that connects the left and right hemispheres.

Cusps

Flaps in heart valves that ensure one-way blood flow.

Endocardium

Smooth inner lining of the heart chambers.

Endothelium

Inner lining of blood vessels.

Epicardium

Outer layer of the heart wall.

Frank-Starling Law

The heart pumps more blood when it receives more blood.

Functional Syncytium

The heart functions as a single coordinated unit.

Heart Sounds

'Lubb' - Closure of AV valves; 'Dupp' - Closure of semilunar valves.

Hydrostatic Pressure

Pressure exerted by blood in vessels.

Inward Oncotic Pressure

Osmotic pressure pulling fluid into blood vessels.

Ions Involved in Depolarization

Sodium (Na⁺) enters, Calcium (Ca²⁺) maintains plateau, Potassium (K⁺) exits.

Isovolumic

No volume change in heart chambers, but pressure changes.

Mediastinum

Cavity in the thorax where the heart is located.

Medulla Oblongata

Brainstem region that controls heart rate.

Mitral Valve

Valve between the left atrium and left ventricle.

Myocardium

Thick muscle layer of the heart responsible for contraction.

Osmotic Pressure

Pressure that draws water into capillaries.

Papillary Muscles

Muscles in ventricles that control valve function.

Parasympathetic Nervous System

Slows heart rate (via Vagus nerve).

Pericardial Membrane/Cavity

Protective sac surrounding the heart.

Pons

Brain region that helps regulate breathing.

P-Q Interval

Time delay between atrial and ventricular contraction.

Pulmonary Arteries

Carry deoxygenated blood from the right ventricle to the lungs.

Pulmonary Valve

Prevents backflow from pulmonary artery to right ventricle.

Pulmonary Veins

Carry oxygenated blood from lungs to left atrium.

Purkinje Fibers

Conduct impulses through ventricles for coordinated contraction.

P-Wave

Represents atrial depolarization on an EKG.

QRS Complex

Represents ventricular depolarization on an EKG.

Regulating BP

Controlled by: Baroreceptors, RAAS system, sympathetic/parasympathetic input.

S-A Node

Pacemaker of the heart, initiates heartbeat.

Shunting Blood

Redirecting blood to priority organs during stress.

Sulci

Grooves on the heart’s surface that contain blood vessels.

SV

Amount of blood pumped per heartbeat.

Sympathetic Nervous System

Increases heart rate and contractility.

Thyroid Hormones

Increase heart rate and metabolic activity.

Tricuspid Valve

Valve between the right atrium and right ventricle.

Tunica Media

Middle layer of blood vessel wall; controls vasodilation & vasoconstriction.

T-Wave

Represents ventricular repolarization on an EKG.

Vagus Nerve

Slows heart rate via parasympathetic input.

Veins

Carry blood to the heart; contain valves to prevent backflow.

Ventricular Volume

The amount of blood contained in the ventricles.