cardiovascular system

systole and diastole The heart has 2 halves and 4 chambers each half has 2 chambers namely an atrium and a ventricle

between the lungs in the mediastinum

separate each chamber preventing the backflow of blood 4 valves - aortic, pulmonary, bicuspid and tricuspid

supply the wall of the heart with blood

• Atria contracts and fills the ventricle with blood, ventricles contract and pumps blood into the pulmonary artery (to the lungs to receive oxygen) and aorta (to the body). Ventricles relax as the atrium begins to fill with blood for another cycle. Fluid pressure in filling atria opens atrioventricular valves and blood flows into the ventricles. • Cardiac output (CO) is seen as the amount of blood each ventricle pumps in a minute. CO can be calculated as the product of heart rate and stroke volume (HR x SV) • The amount of blood in a human body is roughly about 5 litres.

arteries, arterioles, capillaries, venules and veins Blood pumped from the heart into arteries, large diameter flows into arterioles, narrower and smaller branches into capillaries, even narrower

fluids and solutes diffuse into the extracellular fluid and eventually enter the cells. fluid and solutes from the cells enter the extracellular fluid and from there into the blood in the capillaries and blood flows into venules and then veins and return to heart

Pulmonary circulation: blood from tissues (low in oxygen and high in Co2) which comes into the right heart enters the lungs via the pulmonary artery where it is circulated in the lungs for gas exchange. The freshly oxygenated blood enters the left atrium via the pulmonary veins. Systemic circulation: oxygenated blood is received into the left atrium via the pulmonary veins and is pumped via the left ventricle into the aorta (highest pressure) for it to be distributed to the rest of the body. Deoxygenated blood returns to the right part of the heart via the inferior vena cava for it to enter the pulmonary circulation

blood enters RA from superior and inferior venae cava blood in RA flows through right AV valve into RV contraction of RV forces pulmonary valve to open blood flows through PV into P trunk blood distributed by R and L PA to the lungs, unloads CO2 and loads O2 blood returns from lungs via PV to RA blood in LA flows through left AVV into left ventricle LV contracts = aortic valve opens blood in aorta distributed to every organ, unload O2 and load CO2 blood returns to heart via venae cava

-It is a fluid connective tissue that delivers o2 and removes co2 - Transports nutrients, hormones and aids in removing waste from cells to the kidneys - Helps regulate body temperature - Contains various cells with different functions (WBCs/leukocytes fight off infections, RBCs/erythrocytes transport oxygen and CO2, Platelets in blood clots to prevent excessive bleeding) - Blood pressure is the fluid pressure blood exerts against the walls of the blood vessels (highest in aorta and drops in systemic circulation). Normal blood pressure is 120/80

classification of blood based on the presence and absence of antibodies and inherited antigenic substances on the surface of red blood cells - In general, the rarest blood type is AB-negative and the most common is O-positive

4 - A, B, AB and O. Blood groups are genetically determined. Each group can be either RhD positive or RhD negative.

A antigens on the erythrocyte surface, anti-B antibodies in their plasma

B antigens on the erythrocyte surface and anti-A antibodies in their plasma

A and B antigens on the erythrocyte surface and no antibodies in their plasma =universal recipients

no antigens in their erythrocytes with anti-A and anti-B antibodies in the plasma = universal donors

clogging of arteries which leads to its hardening and stiffening and promotes hypertension due to reduced vessel lumen

elevated blood pressure

abnormally low blood pressure

blockages in the coronary arteries thus part of the heart muscle becomes ischemic and dies

weakened pump thus failure to adequately circulate blood in the body in order to meet its needs

RBCs

Amount of blood pumped by the left ventricle in each heart - beat

An inherited protein found on the surface of RBCs