Structures and Functions of the Heart
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Superior Vena Cava: brings oxygenated blood from the body to the heart
Pulmonary Arteries: Carry deoxygenated blood from the right ventricle to the lungs
Right Atrium: receives deoxygenated blood from the body through the vena cava and
pumps it into the right ventricle
Pulmonary Veins: carry oxygenated blood from the lungs to the left atrium of the heart
Right Atrioventricular Valve (tricuspid valve): prevents back flow of blood into the
right atrium
Right Ventricle: pumps blood up through the pulmonary valve and through the
pulmonary artery to the lungs, for it to be oxygenated
Chordae Tendinease: cord like tendons that connect the papillary muscles to the
tricuspid calve and the mitral valve in the heart
Inferior Vena Cava: carries deoxygenated blood from the lower body to the heart
Aorta: carries and distributes oxygen rich blood to all arteries
Left Atrium: receives oxygenated blood from the lungs and pumps it down into the left
ventricle
Pulmonary Semilunar Valve: prevents blood coming from the heart to the lungs, from
flowing back into the heart
Left Atrioventricular Valve: prevents backflow of blood when the left ventricle of the
heart is returning to the relaxed state after pumping
Aortic Semilunar Valve: prevents backflow of blood when the left ventricle of the heart
is returning to the relaxed state after pumping
Left Ventricle: pumps oxygenated blood tissues all over the body
Interventricular Septum: is a muscular wall that separates the left and the right
ventricles of the heart
Myocardium: stimulates contractions and relaxations of the heart
Tracing the Pathway of blood through the heart and the vessels of coronary circulation
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Pulmonary Circuit:
Right Atrium  Tricuspid Valve  Right Ventricle  Pulmonary Semilunar Valve 
Pulmonary Trunk  Pulmonary Arteries  Lungs  Pulmonary Arteries  Let Atrium
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Systemic Circuit:
Left Atrium  Mitral Valve  Left Ventricle  Aortic Semilunar Valve
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Left Coronary Artery: runs toward the left side of the heart and then divides into 2
major branches
Right Coronary Artery: courses to the right side of the heart, where it also gives rise to
2 branches
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Comparing and Contrasting
Arteries:
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Structure: The walls (outer structure) of arteries contain smooth muscle fibre that
contract and relax under the instructions of the sympathetic nervous system.
Functions:
o Transport blood away from the heart
o Transport oxygenated blood only (except in the case of the pulmonary artery)
Arterioles:
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Structure: tiny branches of arteries that lead to capillaries. These are also under the
control of the sympathetic nervous system, and constrict and dialate, to regulate blood
flow
Functions:
o Transport blood from arteries to capillaries
o Are the main regulators of blood flow and pressure
Capillaries:
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Structure: Tiny blood vessels that are networks of capillaries in most of the organs and
tissues of the body. These capillaries are supplied with blood by arterioles and drained by
venules. Capillary walls are only one cell thick which permits exchanges of material
between the contents of the capillary and the surrounding tissue.
Functions:
o To supply the tissues of the body with the components of blood, and carried by
the blood, and also to remove waste from the surrounding cells…as opposed to
simply moving the blood around the body (in the case of other blood vessels)
o Exchange of oxygen, carbon dioxide, water, salts, etc., between the blood and the
surrounding body tissues
Venules:
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Structure: minute vessels that drain blood from capillaries and into veins. Many venules
unite to from a vein.
Functions:
o Drains blood from capillaries into veins, for return to the heart
Veins:
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Structure: The walls of veins consist of 3 layers of tissues that are thinner and less elastic
than the corresponding layers of arteries. Veins include calves that aid the return of blood
to the heart by preventing blood from flowing in the reverse direction
Functions:
o Transport blood toward the heart
o Transport deoxygenated blood only (except in the case of the pulmonary vein)
Performing a Blood Pressure Test and Results
Steps:
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Equipment for measuring blood pressure
Introduce yourself to patient
Select correct cuff size to suit patient
Ensure correct placement of the cuff  brachial artery
Inflate cuff to determine a rough value for the systolic blood pressure
Record true blood pressure and deflate cuff
Results:
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Normal B.P.:
o 140 to 110 mm Hg Systolic
o 80 to 73 mm Hg Diastolic
Hypotension B.P:
o Low Systolic (below 110 mm Hg)
o Often associated with illness
Hypertension B.P.:
o High Systolic (above 140 mm Hg)
o Can be dangerous is chronic