Cardiovascular System and Blood Vessels (Terms related to heart function…
Cardiovascular System and Blood Vessels
Anatomy of the Heart
Arteries transport blood away from the heart
Pulmonary trunk transports from the right side
Aorta transports from the left side
Veins transport blood towards the heart
Vena cavae (superior and inferior) drain into the right side
Pulmonary veins drain into left side
Valves have muscles attached
Also known as mitral valve or Left atrioventricular valve
Also known as the Right Atrioventricular valve
Valves do not have muscles attached
Pulmonary semilunar valve
Aortic semilunar valve
Muscles of the heart
middle layer of the heart
internal surface of the heart and the external surfaces of the heart valves
simple squamous epithelium and areolar connective tissue
outermost heart layer
simple squamous epithelium and areolar connective tissue and adipose connective tissue
Right and left atrial chambers are separated by a thin wall
Right and left ventricles are separated by a thick wall
Found in the right and left ventricles
Right ventricle extending from the internal wall are typically 3 cone-shaped, muscular projections
The number of papillary muscles can range from 2-9
Left ventricle extending from the internal wall are 2 cone-shaped, muscular projections
Papillary muscles anchor thin strands of collagen fibers called chordae tendineae
Found in the right and left atrium
Muscular ridges found on the anterior wall and within the auricle
Atrioventricular bundle (AV) also called the bundle of His, extends from the AV node into and through the inter ventricular septum. It divides into left and right bundles.
Purkinje fibers extend from the left and right bundles from the apex of the heart and then continue through the walls of the ventricles.
Atrioventricular node (AV) is located in the floor of the right atrium between the right AV valve and the opening for the coronary sinus.
Heart rate is initiated by the SA node, both heart rate and the strength of the contraction are regulated by the autonomic nervous system.
Cardioacceleratory center sends nerve signals along sympathetic nerves, which results in an increase in both heart rate and force of contraction.
Cardioinhibitory center sends nerves signals along vagus nerves (CN X), which results in a decrease in heart rate and contraction.
Sinoatrial node (SA) is located in the posterior wall of the atrium, adjacent to the entrance of the superior vena cava.
The cells here initiate the heartbeat and are commonly referred to as the pacemaker of the heart.
Cardiac muscle contraction
Cardiac muscle tissue is made up of relatively short, branched cells that usually house one or two central nuclei
These muscle cells are supported by areolar connective tissue, called endomysium, that surrounds the cells.
exchange of substances between blood and tissues
bring blood towards the heart
thinner lined walls
smallest arteries, with diameters ranging from 0.3 mm to 10 micrometers
smallest veins, measuring from 8 to 100 micrometers in diameter
blood away from the heart
Terms related to heart function
End diastolic volume
Ventricles are filled and hold their maximum blood volume approximately 130 mL of blood
End systolic volume
Not all blood in either ventricle is ejected, the blood remaining in a ventricle after systole; ESV is found by subtracting SV from EDV
number of beats per minute
volume of blood returned to the heart via the great veins and is directly related to stroke volume
Amount of blood pumped out during ventricular systole approximately 70 mL of blood
stretch of the heart wall due to "the load to which cardiac muscle is subjected before shortening
the amount of blood that is pumped by a single ventricle in 1 minute; HR x SV=CO
resistance in arteries to the ejection of blood by the ventricles and it represents the pressure that must be exceeded before blood is ejected from the chamber
the volume of blood entering the heart increases, there is a greater stretch of the heart wall. This results in a greater overlap of the thick and thin filaments in the sarcomeres of the cardiac muscle cells composing the myocardium.
Atrial relaxation and ventricular filling
Atrial contraction and ventricular filling