Circulatory system

Circulatory System

System responsible for transportation of blood and nutrients throughout the body.

Heart

Muscular organ that pumps blood throughout the circulatory system.

Blood

Liquid connective tissue that carries oxygen, nutrients, and waste products.

Blood Vessels

Tubular structures that carry blood throughout the body.

Transportation of oxygen

Function of the circulatory system to deliver oxygen to cells.

Removal of carbon dioxide

Function of the circulatory system to eliminate waste products from cells.

Regulation of body temperature

Function of the circulatory system involving vasoconstriction and vasodilation.

Transportation of hormones

Function of the circulatory system to distribute hormones throughout the body.

Assistance with immune response

Function of the circulatory system in supporting the body's defense mechanisms.

Atria

Upper chambers of the heart that receive blood from the body.

Ventricles

Lower chambers of the heart that pump blood out of the heart.

Pulmonary Valves

Semilunar valves that allow ejection of blood into arteries.

Aortic Valves

Valves that regulate blood flow from the heart into the aorta.

Tricuspid Valve

Atrioventricular valve located between the right atrium and right ventricle.

Bicuspid Valve

Atrioventricular valve located between the left atrium and left ventricle.

Pericardium

Outer membrane that surrounds and protects the heart.

Myocardium

Thick layer of cardiac muscle making up the walls of the heart.

Chordae tendineae

Tendon-like cords that prevent backflow of blood through the valves.

Trabeculae carneae

Ridges caused by raised bundles of cardiac muscles in the ventricles.

Papillary Muscles

Cone-shaped muscles to which the chordae tendineae are attached.

Apex

Inferior portion of the heart that comes to a point.

Base

Broad, superior portion of the heart.

Septum

Muscular partition that prevents blood on two sides from mixing.

Pericardial fluid

Slippery secretion that reduces friction as the heart moves.

Cardiac Cycle

Sequence of events in a single heartbeat, lasting approximately 0.8 seconds.

Cardiac Output

Volume of blood pumped from the heart per minute.

Stroke Volume

Amount of blood pumped per ventricle per contraction.

Heart Rate

Number of beats/contractions of ventricles per minute.

Epinephrine

Hormone that increases heart rate during stress or excitement.

Sinoatrial (SA) Node

Pacemaker of the heart that initiates each heartbeat. Sends action potential to both atria causing them to contract

Right Atrial wall

Electrocardiogram (ECG or EKG)

Recording of the electrical changes that accompany the heartbeat.

Tachycardia

Rapid resting heart rate over 100 bpm.

Bradycardia

Slow resting heart rate under 60 bpm.

Arrhythmia

Irregularity in heart rhythm caused by problems in the conduction system.

Atrial Fibrillation

Uncoordinated contraction of atrial muscles.

Ventricular Fibrillation

Asynchronous, haphazard ventricular muscle contractions.

Heart Murmur

Faulty heart valves causing gurgling sounds.

P wave

Atrial Depo - 

Electric current spreads from pacemaker over the atria

QRS Complex

Onset of Vent Depo

Electrical Impulse spreads to the ventricles

T Wave

Vent Repo - Ventricles relax

Atrialventricular node

Interatrial Septum

Picks up action potential from SA node and passes it to the atrioventricular bundle

Atrioventricular (AV) bundle (bundle of His)

Interventricular Septum

Picks up action potential from AV node and passes it to the right and left bundle branches

Right and left bundle branches

Interventricular Septum

Picks up action potential and passes it to conduction myofibers

Conduction myofibers (Purkinje fibers)

Ventricular myocardium

Picks up action potential from bundle branches and passes it to ventricular myocardial cells, causing ventricles to contract.