CIRCULATORY SYSTEM

THE HEART AND BLOOD VESSELS

Learning Outcomes:C3 – Describe the interrelationships of the

structures of the heartIdentify structures diagrams and give

functions and direction of blood flowC5 – analyze the functional

interrelationships of the vessels of the circulatory systemDescribe the 5 types of blood vessels in

terms of structure and functionIdentify and give the function of the blood

vessels of the body

The Heart

Mostly muscle (myocardium)Enclosed in a sac (pericardium)Right and left side separated by septumFour chambers:

Right and left atria (receive blood)Right and left ventricles (pump blood out)

Heart ValvesPrevent backflow of bloodAtrioventricular valves -

between atria and ventricles(tricuspid on right, bicuspid /

mitral on left)Semilunar valves - between

ventricles and arteriesChordae tendinae support the

atrioventricular valves

A Double Pump

Right: receives blood from the body and pumps it to the lungs

Left: receives blood from the lungs and pumps it to the body

Fig. 13.4b

Blood Vessels of the HeartSuperior and inferior vena cava - from

upper and lower body to the right atriumPulmonary trunk - branches into R and L

pulmonary arteries - to the lungsPulmonary veins - from lungs to heartAorta - from left ventricle, branches to

all parts of the bodyCoronary arteries - supply the heart

muscle

Fig. 13.3b

Fig. 13.4a

BLOOD VESSELS5 types arteries - carry blood away from the heart;

thick, muscular wallsarterioles – smaller branches of the arteriesveins – carry blood toward the heart;

thinner walls, have valves to prevent backflow

venules – smaller branches of veinscapillaries – networks of microscopic

vessels in all tissues; walls are very thin (one cell thick); connect veins and arteries; supply cells with nutrients

Fig. 13.1

Fig. 13.2

AssignmentDraw arrows in red and blue on your

diagram to show the flow of oxygenated and deoxygenated blood through the heart

List in order all the structures blood would flow through as it passes through the heart and lungs, starting with the vena cava and ending with the aorta