all of the tissues and fluids in the body rely on the cardiovascular system to maintain homeostasis.
Proper functioning of the cardiovascular system
depends on the activity of the heart, which can vary its pumping capacity depending on the needs of the peripheral tissues
Circuit functions individually
Circuit functions together
carries oxygen-poor blood from the heart to the lungs and back
transports oxygen-rich blood from the heart to the rest of the body and back.
carry blood away from the heart
return blood to the heart
tiny vessels between the smallest arteries and veins
Right atrium and ventricle
pumps blood into the pulmonary arteries
Left atrium and ventricle
receives blood from pulmonary veins
collect blood returning to the heart
discharge blood into vessels to leave the heart
surround the heart
epithelium cells that surround the heart
small amount of lubricating fluid that contain by pericardial cavity
Visceral pericardium (epicardium)
covers the heart's outer surface
lines in the inner surfaces of the pericardial sac
surrounds the heart and help prevent overfilling.
where heart lies in the anterior portion
muscular wall of the heart
epithelium covering the inner surfaces of the heart including the valves.
bulk of the heart
Cardiac muscle cells (cardiocytes)
smaller than skeletal muscle cells, are almost totally dependent on aerobic respiration.
supplies blood to the heart muscles
Cardiac muscle cells
do not require nervous stimulation to contract
interconnected cardiocytes; convey the force of contraction from cell to cell and conduct action potentials.
Intercalated discs join cardiac muscles cells through
desmosomes, myofibrils, and gap junctions; Function like single, enormous cell
internal connective tissues of the heart
Fibrous skeleton of the heart functions to
stabilize the heart's contractile cells and valves; support the muscle cells, blood vessels, and nerves; distribute the forces of contraction; add strength and eleasticity; and physically isolate the atria from the ventricles
Auricle (atrial appendage)
expandable extension of the atrium
deep grove between the atria and ventricles
Anterior interventricular sulcus and posterior interventricular sulcus
other shallower depressions between the atria and ventricles
superior end of the heart where the great vessels are connected
inferior, pointed tip of the heart
borders, superior, inferior, left and right; heart site at an angle to the longitudinal axis of the body
formed by the anterior surfaces of the right atrium and ventricle
formed primarily by the posterior, inferior wall of the left ventricle.
separated the atria
separated the ventricle
Opening between the atria and ventricles
contains fold of the connective tissue covered by endocardium; these valves maintain a one-way flow of blood.
Superior vena cava and inferior vena cava
the right atrium receives blood from the systemic circuit
prominent muscular ridges within the atria walls
return blood to the coronary sinus which opens into the right atrium.
opening during embryonic development that penetrate the interatrial septum
depression that originate from the foramen ovale when it closes after birth
Atrioventricular (AV) valve
or tricuspid valve; blood flow from the right atrium into the right ventricle; consists of three cusps of fibrous tissue braced by the tendinous chordae tendineae that are connected to papillary muscles.
blood leaving the right ventricle enters the pulmonary trunk after passing through the pulmonary valve.
The pulmonary trunk divides to form the
Left and right pulmonary arteries
Left and right pulmonary veins
left atrium receives oxygenated blood from; has thicker walls than those of the right atrium
Left atrioventricular (AV) valve (bicuspid valve or mitral)
blood leaving the left atrium flows into the left ventricle
largest and thickest of the four chambers because it pump blood to the entire body
blood leaving the left ventricle
blood leaving the left ventricle through the aortic valve and into the systemic circuit
blood passes from the ascending aorta through aortic arch and into the descending aorta
has thin walls and develops low pressure when pumping into the pulmonary circuit to and from the adjacent lungs.
functionally, low pressure is necessary because the pulmonary capillaries at the gas-exchange surfaces of the lungs are very delicate.
thick wall because it pumps blood throughout the systemic circuit.
AV valves have four components
a ring of connective tissues attached to the fibrous skeleton of the heart; cusps; chordae tendineae and papillary muscles
aortic valve and pulmonary valve
Aortic and pulmonary valves
guarding the exits of the left and right ventricles
backflow of blood
the closure of valves and rushing of blood through the heart; can be heart during auscultation.
supplies blood to the muscles of the heart to meet the high oxygen and nutrient demands of cardiac muscles.
originate at the base of the ascending aorta, and each gives rises to two branches
Right marginal branch and posterior interventricular branch
rises given by the right coronary artery
Left coronary artery
givers rise to both a circumflex branch and an anterior interventricular branch
interconnections between arteries; ensures a constant blood supply.
Great and middle cardiac veins
carry blood from the coronary capillaries to the coronary sinus
Anterior cardiac veins
drain the anterior surface of the right ventricle and empty directly into the right atrium.
consists of periods of atrial and ventricular systole and atrial and ventricular diastole
contraction and AV valves are closed
Automaticity or autorthythmicity
cardiac muscle tissue contracts on its own, without neural or hormonal stimulation
establish the rate of cardiac contraction; delpolarize spontaneously and determine the heart rate
distribute the contractile stimulus to the general myocardium
found in the sinoatrial node (cardiac pacemaker) normally establish the rate of contraction
Wall of the right atrium
main pacemaker region of the heart
From the SA node,
the stimulus travels over the internodal pathways to the atrioventricular node, then to the AV bundle, which divides into a right and left bundle branch.
convey the impulses to the ventricular myocardium
chambers of the heart fill up
During one cardiac cycle
the heart spends most of its time in diastole
During the period of systole
inner volume of atrial chambers decreases.
a recording of electrical activities in the heart
Important landmarks of the ECG
P wave, QRS complex, and T wave
ECG analysis reveals
the condition of the conducting system and can detect cardiac arrhythmias
abnormally patterns of cardiac activity.
time between ventricular contraction and relaxation
Basic heart rate
establishes by the pacemaker cells, can be modified by the ANS.
produce an increase in heart rate and force of contraction
produce a decrease in heart rate and contraction
in the meduall oblongata activated sympathetic neurons
governs the activities of the parasymphathetic neurons.
receive inputs from higher centers and from receptors monitoring blood pressure and the concentrations of dissolved gases in the blood.