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In this way, the same flow through the coronary circulation is maintained over a range of pressures. This part of coronary circulatory regulation is known as auto regulation and it occurs over a plateau, reflecting the constant blood flow at varying CPP & resistance. The slope of a CBF (coronary blood flow) vs. CPP graph gives 1/Resistance.
These subjects are sometimes addressed separately, under the names cardiac physiology and circulatory physiology. [ 1 ] Although the different aspects of cardiovascular physiology are closely interrelated, the subject is still usually divided into several subtopics.
Cardiac physiology or heart function is the study of healthy, unimpaired function of the heart: involving blood flow; myocardium structure; the electrical conduction system of the heart; the cardiac cycle and cardiac output and how these interact and depend on one another.
This function is so significant to normal functioning of the circulatory system that the cardiovascular centre is considered a vital centre of the medulla oblongata. [ 2 ] [ 3 ] Hormones like epinephrine and norepinephrine can affect the cardiovascular centre and cause it to increase the rate of impulses sent to the sinoatrial node , resulting ...
However, neither Frank nor Starling was the first to describe the relationship between the end-diastolic volume and the regulation of cardiac output. [5] The first formulation of the law was theorized by the Italian physiologist Dario Maestrini , who on December 13, 1914, started the first of 19 experiments that led him to formulate the "legge ...
The funny current is highly expressed in spontaneously active cardiac regions, such as the sinoatrial node (SAN, the natural pacemaker region), the atrioventricular node (AVN) and the Purkinje fibres of conduction tissue. The funny current is a mixed sodium–potassium current that activates upon hyperpolarization at voltages in the diastolic ...
Myocardial contractility represents the innate ability of the heart muscle (cardiac muscle or myocardium) to contract. It is the maximum attainable value for the force of contraction of a given heart.
This alters the cardiac function curve, shifting it upwards. This allows the heart to cope with the required cardiac output at a relatively low right atrial pressure. We get what is known as a family of cardiac function curves, as the heart rate increases before the plateau is reached, and without the RAP having to rise dramatically to stretch ...