Pulmonary circuit
Blood flow to and from the gas exchange surface of the lung
Systemic circuit
transport blood to and from the rest of the body
Arteries
or efferent vessels that carry blood away from the heart
Arterioles
last small branches of the arterial system with control valves to capillaries
Capillaries
small, thing walled vessels originating from the arterioles that permit exchange of nutrients
Venules
collect blood from the capillaries
Veins
or afferent vessels that carry blood to the heart from the venules
Right atrium
The upper right chamber of the heart, where deoxygenated blood is received from the vena cava and then sent to the right ventricle.
Right ventricle
the chamber on the right side of the heart that receives venous blood from the right atrium and pumps it into the pulmonary trunk (pulmonary circuit)
Left atrium
the left upper chamber of the heart that receives blood from the pulmonary veins and empties it to the left ventricle
Left ventricle
the chamber on the left side of the heart that receives arterial blood from the left atrium and pumps it into the aorta (systemic circuit)
Heart Base
area of outflow valves, fairly cranial; superior end of the heart
Heart Apex
area of mitral valve (L) and tricuspid valve (R); inferior pointed tip of the heart
Pericardial cavity
the space between the layers of the pericardium (parietal and visceral) that contains fluid that lubricates the membrane surfaces and allows easy heart movement
Mediastinum
partition that separates the thorax into two compartments (that contain the right and left lung) and encloses the heart, esophagus, trachea, and thymus gland
Visceral pericardium
or epicardium covers the outer surface of the heart
Parietal pericardium
Membrane that forms the inner layer of the pericardial sac which sorrounds the heart
Pericardial fluid
found in the pericardial cavity, exuded by the serous pericardium, lubricates the membranes and allows the heart to beat almost without friction; isolates the heart from other organs, allows the heart room to expand and yet prevents excessive expansion
Auricle
wrinkled pouch on anterior surface of each atrium, slightly increases the capacity of an atrium so that it can hold a greater volume of blood
Coronary sulcus
This is the name of the groove or depression between the atria and the ventricles and it is in part of this sulcus that we find the coronary sinus. We find some of the larger coronary arteries and veins in this groove.
Interventricular sulcus
mark the septum that separates the right and left ventricles
Epicardium
the external layer of the heart (visceral pericardium) and the inner layer of the pericardium
Myocardium
The middle layer of the muscle. It is thick and composed of cardiac muscle tissues and associated connective tissues, blood vessel , and nerves. This layer produces the heart contraction.
Endocardium
smooth layer of cells that lines the insides of the heart (simple squamous epithelium) and is continuous with the insides of the blood vessels; allows for smooth blood flow
Cardiac muscle tissue
Cardiac muscle cells are small, have a single nucleus, have branching interconnection between cells, and have intercalated disc connecting individual cells
Interatrial septum
muscular wall sepatating the two atria
Interventricular septum
muscular wall separating the two ventricles
Atrioventricular valves
one way valves between the atria and ventricles
Superior vena cava
large vein that brings oxygen-poor blood from the upper part of the body to the right atrium
Inferior vena cava
vein that receives blood from lower limbs and abdominal organs and empties into the posterior part of the right atrium of the heart
Coronary sinus
enlarged vein from junctions of all cardiac veins which empty into the right atrium
Foramen ovale
penetrates interatrial septum from fifth week of embryonic development until birth
Fossa ovalis
A small depression left in the interartrial septum as a result of the closure of the foramen ovale after birth
Right atrioventricular valve
AKA the tricuspid valve. Allows blood to flow from the right atrium into the right ventricle. It is bounded by three fibrous flaps called cusps and is located between the right atrium and the right ventricle.
Chordae tendinae
cord-like tendons that connect the papillary muscles to the tricuspid valve and the mitral valve in the heart.; connected to papillary muscles
Papillary muscles
Finger like or coned shaped muscular projections located on the inner surface of the ventricles
Pulmonary trunk
the artery that carries venous blood from the right ventricle of the heart and divides into the right and left pulmonary arteries
Pulmonary semilunar valve
Valve that lies between the right ventricle and the pulmonary artery and has 3 cusps. Blood flows from the right ventricle throught the pulmonary valve to become oxygenated
Pulmonary arteries
arteries that carry deoxygenated blood from the heart (pulmonary trunk) to the lungs (left and right)
Pulmonary veins
vessels that carry oxygenated blood from the lungs to the left atrium
Left atrioventricular valve
located between the left atrium and left ventricle - prevents backflow - also known as mitral valve and bicuspid valve
Aortic semilunar valve
located between the aorta and the left ventricle to prevent the backflow of blood
Ascending aorta
the ascending part of the aorta as it emerges from the left ventricle
Aortic arch
the part of the aorta that curves before becoming the descending aorta
Descending aorta
the descending part of the aorta that branches into the thoracic and abdominal aortae
Coronary circulation
circulation of blood through the coronary blood vessels to deliver oxygen and nutrients to the heart muscle tissue
Right coronary artery
originates at the base of the ascending aorta and supplies the right atrium, and portion of both ventricles.
Posterior interventricular artery
branch of the right coronary artery that runs in the post interventricular sulcus and supplies this septum and adjacent portions of ventricles
Left coronary artery
originates at the base of the aorta and supplies the left ventricle, left atrium, and interventricular septum
Circumflex artery
curves left around coronary sulcus and fuses with branches of the RCA
Anterior interventricular artery
(know clinically as the left anterior descending artery), branch of left coronary artery; travels down anterior interventricular sulcus toward apex; supplies interventricular septum and anterior walls of ventricles
Arterial anastomoses
When two arteries merge and provide alternative routes of blood supply to a tissue:
Great cardiac vein
The anterior vein of the heart that runs in the interventricular sulcus, and feeds into the coronary sinus at its left end
Coronary sinus
The great, middle, and small cardiac veins all empty into here, which in turn empties into the right atrium.
Middle cardiac vein
vein that drains the area supplied by the posterior interventricular artery
Contractile cells
Produce the powerful contractions that propel blood
Conducting cells
specialized muscle cells of the conducting system which coordinates the heart beat
Cardiac cycle
the complete cycle of events in the heart from the beginning of one heart beat to the beginning of the next
Automaticity
The ability of the heart to generate and conduct electrical impulses on its own in the absence of neural or homonal stimulation
Conducting system
connect the SA and AV nodes and distributes the contractile stimulus
SA node
the pace-maker of the heart; where the impulse conduction of the heart usually starts; located in the top of the right atrium
AV node
an area of specialized tissue between the atria and the ventricles of the heart, which conducts the normal electrical impulse from the atria to the ventricles.
Conducting cells
the cells responsible for initiating and distributing the stimulus to contract
AV bundle
travels along interventricular septum before dividing into left and right bundle branches
Purkinje fibers
The smallest (and final) fibers in the cardiac conduction system. The Purkinje fibers transmit the cardiac impulse to the ventricular myocardium
Systole
the period in which a chambers pushes blood into another chamber or into an arterial trunk
Diastole
the relaxation phase when the chambers fill with blood in preparation for the next cycle
Phases of the cardiac cycle
Atrial systole, ventricular systole, and ventricular diastole
Cardiodynamics
refers to the movements and forces generated during cardiac contractions
Stroke volume
the amount of blood ejected by each ventricle during a single heart beat
Cardiac output
amount of blood pumped by each ventricle in one minute