Blood and Cardiovascular System PDF

BLOOD and CARDIOVASCULAR SYSTEM Objectives: Parts and functions of the cardiovascular system? What is the anatomy of the heart and blood vessels (veins and arteries)? Blood composition and functions Blood flow and cardiovascular pathways in the body Common cardiovascular diseases What...

BLOOD and CARDIOVASCULAR SYSTEM Objectives: Parts and functions of the cardiovascular system? What is the anatomy of the heart and blood vessels (veins and arteries)? Blood composition and functions Blood flow and cardiovascular pathways in the body Common cardiovascular diseases What is the cardiovascular system? Includes the heart and blood vessels Brings nutrients to cells and helps get rid of wastes Blood is refreshed in the lung, kidneys, intestine and liver Lymphatic vessels help this system by collecting excess fluid surrounding tissues and return it to the cardiovascular system The main pathway of blood in the body? Heart – arteries – arterioles – capillaries - venules – veins – back to the heart… Arteries and arterioles: Carry oxygenated blood away from the heart (except Pulmonary artery) Their walls have 3 layers: Thin inner Endothelium Thick smooth muscle layer Outer connective tissue Arteries branched off into smaller blood vessels called Arterioles Veins and venules: Veins carry deoxygenated blood toward the heart (except Pulmonary vein) Their walls have 3 layers: Thin inner epithelium Smooth muscle layer (thinner than those in arteries) Outer connective tissue Veins that carry blood against gravity have valves to keep blood flowing toward the heart Veins branched off into smaller blood vessels called Venules  Capillaries Microscopic vessels between arterioles and venules Made of one layer of epithelial tissue ( endothelium) Form beds of vessels where exchange with body cells occurs Combined large surface area surrounding different tissues Blood composition  Erythrocytes (RBC) contain hemoglobin, the iron-containing protein that transports oxygen. WBC ( Leucocytes) : - Neutrophils : Phagocytosis, bacterial infection - Lymphocytes: Kill viruses, Antibodies production - Eosinophils: Allergy, kill Parasites - Monocytes: Phagocytic function - Basophiles: release chemicals that trigger inflammation Erythrocytes, leukocytes, and platelets (Thrombocytes) all develop from a common source of stem cells in the red bone marrow.  Anatomy of the heart: A large, muscular organ consisting of mostly cardiac tissue called the myocardium It is surrounded by a sac called the pericardium Consists of two sides, right and left, separated by a septum Consists of 4 chambers: 2 atria and 2 ventricles 2 sets of valves: semilunar valves and atrioventricular valves (AV valves) Closing and opening of the valves give the resulting “lub” and “dup” sound of the heart two cardiovascular pathways in the body Pulmonary circulation: is a short loop from the heart to the lungs and back again Systemic circulation : carries blood from the heart to all the other parts of the body and back again The  Atherosclerosis ▪ Atherosclerosis thickening or hardening of the arteries. It is caused by a buildup of plaque in the inner lining of an artery. Plaque is made up of deposits of fatty substances, cholesterol, cellular waste products, calcium, and fibrin Heart attack Also known as a myocardial infarction (MI) Part of the heart dies due to lack of oxygen Can begin with angina pectoris, a pain that radiates down the left arm due to a blockage of a coronary artery