Learning outcomes:
● Identify the chambers of the heart.
● Identify the location and function of valves within the heart.
● Describe the flow of blood through the heart.
● Define stroke volume and cardiac output.
● Understand how the cardiovascular system responds to exercise.
● Understand how cardiac output and blood pressure can be measured.
● Understand how heart rate, stroke volume and cardiac output change with
exercise.
Introduction:
The heart is a strong muscular pump with 2 complementary sets of vessels: one for
the systemic and one for the pulmonary circulation. The pumping of the heart is
essential in the delivery of oxygen to the millions of cells of the body and in the
removal of their waste products. The heart pushes deoxygenated blood to the
lungs and oxygenated blood around the entire body. It must continually beat to
sustain life and so its muscular walls are made of specialized cardiac muscle cells
that carry their own intrinsic contractile rhythm.
All cells within the body must be supplied with enough oxygenated blood each
minute to meet their cellular metabolic demands. During exercise and processes
such as tissue repair, cells are metabolically active and require more oxygen from
the blood, thus increasing the workload of the heart. At rest, the metabolic
demands of cells are less and therefore the heart doesn't need to work as hard to
supply them with the oxygen they require. The body must adapt to these changing
requirements. Cardiac output is a measure of the flow of blood. We will examine
the variables that make up the cardiac output, learn how to measure these
variables, and then put some experiment subjects to work to see how exercise
, alters cardiovascular function. Let’s head to the cardiac exercise lab!