7.1

• lymphatic system - redistributes intercellular fluid and provides an important route of transport for cells of the immune system.
• The immune system fights foreign invaders through a combination of cellular and chemical defenses.
• arteries carry blood from the heart to capillary beds
• Veins return blood to the heart.
• The heart is a muscular double pump whose contractions push blood through the circulatory system.
• The heart is surrounded by a thin membranous sac, the pericardium, which supports and lubricates the heart during contraction.
• The atrial septum divides the two atria,
• interventricular septum divides the two ventricles.
• Returning to the heart via the left and right pulmonary veins, oxygenated blood enters the left atrium.
• Major veins empty into the venae cavae, which return blood to the right atrium, completing the cycle.
• systole, develops pressure and forces blood through the system.
• diastole, allows the chamber to fill again.
• Atrial systole occurs slightly before ventricular systole and is

  not as forceful.
• The familiar “lubb-dupp” sound of the heartbeat is actually the sound of the valves
• “lubb” is the closing of the two AV valves at the start of ventricular systole,
• “dupp” is the closing of the two semilunar valves as arterial backpressure forces them shut at the start of ventricular diastole.
• BP is the measure of the force of blood on the arterial walls.
• MI occurs when the heart receives inadequate blood supply through the coronary arteries.
• Aneurysm - A bulge in a vessel, usually an artery, caused by weakening of the wall or hypertension; without surgical correction,
• Arteriosclerosis - Accumulation of fatty deposits on the tunica intima of arteries, causing thickening and toughening of the arterial wall;
• Stroke - A loss of blood to the brain as a result of either hemorrhage or, more commonly, blocked circulation
• Congestive heart failure - Inadequate heart output, leading to edema of the peripheral tissues
• Coronary artery disease - Any type of degenerative change in the coronary arteries including coronary atherosclerosis.
• Rheumatic heart disease - Autoimmune disease affecting cardiac tissue; caused by a previous streptococcal infection elsewhere in

  the body.
• Valvular heart disease is the thickening and calcification of a valve that causes stenosis.
• Valvular heart disease causes heart murmur and may lead to congestive heart failure
• Hemorrhoids - Swollen veins in the walls of the anus, often resulting from prolonged exertion or pressure during defecation
• Varicose veins - Veins that are tortuous and dilated because of swelling and loss of function of valves;
• Veins have thinner walls and less muscle than arteries do, because they do not experience large fluctuations in blood pressure.
• To help prevent backflow of blood, veins have valves within them at various points.
• Most blood tests are performed on venous blood
• The antecubital fossa is the area just distal to the elbow joint where blood is usually drawn.
• The antecubital fossa - This area is easily accessible and contains several prominent veins that are usually located a safe distance from nerves and arteries,
• most prominent of these (MV) are the cephalic vein,
• The median cubital vein splits just below the elbow, sending one branch to the basilic vein and one branch to the cephalic vein.
• The brachial artery passes through the elbow, splitting into

  the radial and ulnar arteries.
• oxygen-depleted blood is returned to its origin through e veins.
• The coronary circulation supplies the bloods as well as provides drainage to e tissue.
• Electrical conduction system - sends electric impulses throughout the myocardium which is initiated by the SA nodes.
• ECG - provides the graphical representation of e cardiac cycles's activity.