Cardiovascular system
The heart, blood vessels, and capillaries in charge of distributing blood throughout the body's cells.
Arteries
carry blood away from the heart
Veins
carry blood towards the heart
Capillaries
sites of exchange
Right Side
receives deoxygenated blood and pumps it to the lungs
Left Side
Receives oxygenated blood and pumps it to the body
Atrium
first chamber on both the right and left side
Ventricle
second chamber on both the right and left side
Great vessels
vessels continuous with chambers
Valves
ensure blood flows in one direction
Atrioventricular valves
separate atria from ventricles
Tricuspid (right AV valve)
separates right atria from right ventricle
Bicuspid (left AV valve, mitral valve)
separates left atria from left ventricle
Semilunar valves
separates ventricles from their arteries
Pulmonary semilunar valve
separates right ventricle and pulmonary trunk
Aortic semilunar valve
separates left ventricle and aorta
Pericardium
layers surrounding the heart
Fibrous pericardium
most superficial layer, composed of tough, dense irregular connective tissue
Serous pericardium
two deepest layers, provide lubrication via serous fluid
Parietal layer
simple squamous epithelium with areolar connective tissue lining
Visceral layer (epicardium)
simple squamous epithelium with areolar connective tissue lining, adheres directly to the heart
Pericardial cavity
potential space between the parietal and visceral layer
Coronary sulcus (atrioventricular sulcus)
groove that separates the atria from the ventricles externally
Interventricular sulcus
groove that separates the ventricles externally
Auricles
extensions of the atria
Epicardium
Most superficial layer, Visceral layer of serous pericardium
Myocardium
Middle layer, Cardiac muscle
Endocardium
Deep layer, Simple squamous epithelium with areolar base
Interatrial septum
wall separating the atria
Interventricular septum
wall separating the ventricles
Pectinate muscle
muscular ridges in the right auricle
Fossa ovalis
depression where the foramen ovale used to be
Foramen ovale
fetal opening between right and left atria
Coronary sinus
drains deoxygenated blood from the heart wall
Trabeculae carneae
muscular ridges
Papillary muscles
anchor chordae tendineae
Chordae tendineae
attachments to the tricuspid valve
Intercalated discs
where two cardiac muscle cells connect
Desmosomes
membrane junction, with plaque and filaments
Gap junction
protein pores between two adjacent cells
Fibrous skeleton
dense irregular connective tissue frame
Coronary circulation
blood vessels supplying the heart with blood
Coronary arteries
transport oxygenated blood to heart walls
Coronary veins
transport deoxygenated blood away from heart walls
Left coronary artery
Originates from the ascending aorta, Resides in the coronary sulcus
Circumflex artery
Lateral wall of left ventricle
Anterior interventricular artery
Supplies the anterior wall of the left and right ventricle
Right coronary artery
Originates from the ascending aorta, Resides in the coronary sulcus
Right marginal artery
Supplies lateral wall of right ventricle
Posterior interventricular artery
Supplies posterior wall of left and right ventricles
Coronary sinus
Empties into the right atrium, Resides in the coronary sulcus
Great cardiac vein
Drains anterior walls of both ventricles and left atrium
Middle cardiac vein
Drains posterior walls of both ventricles
Small cardiac vein
Drains posterior walls of the right atrium and right ventricle
Myocardial infarction (heart attack)
sudden and complete occlusion of a coronary artery
Conduction system
cardiac muscle cells that initiate and conduct an electrical signal
Conduction system
cardiac muscle cells that initiate and conduct an electrical signal
Sinoatrial (SA) node
Posterior wall of the right atrium, Initiate heartbeat
Atrioventricular (AV) node
Floor of right atrium, Stimulates the ventricles via the atrioventricular (AV) bundle
Atrioventricular (AV) bundle
Muscle cells descending from the AV node into the ventricles, Splits into left and right bundles
Purkinje fibers
Specialized cardiac cells which transmit electrical signals from the AV bundle to the ventricles
Conduction system
Electrical activity is initiated in the SA node
Nodal cells
pacemaker cells of the SA node that initiate a heartbeat
Autorhythmicity
the ability to depolarize and generate an action potential without external influence
EKG (Electrocardiogram)
detects electrical changes within the heart
P wave
atrial depolarization
QRS complex
ventricular depolarization
T wave
ventricular repolarization
PR interval
time from atrial depolarization (P wave) to the beginning of the ventricular depolarization (QRS complex)
QT interval
time from the beginning of the QRS complex to the end of the T wave
Cardiac cycle
the changes within the heart from the initiation of one heart beat to the next
Sistole
contraction of a heart chamber
Diastole
relaxation of a heart chamber
Cardiac output
amount of blood pumped by a single ventricle in one minute (L / min)
Chronotropic agents
factors that change heart rate
Atrial reflex
prevents heart from over filling
Stroke volume
volume of blood ejected per heartbeat
Venous return
the volume of blood returned to the heart via the great veins
Preload
cardiac muscle stretch before contraction
Inotropic agents
impact contractility (force of contraction) via autonomic innervation and / or hormones
Afterload
resistance of blood ejection by the arteries