THE NEED FOR A TRANSPORTMain idea: our body must continually bring essential substances to the cells and get rid of waste.Circulatory system = the processes of transporting or carrying substances and oxygen from one part of the body to another.

Human circulatory systemMain idea: the human circulatory system consists of organs and structures that transport vital substances and remove wastes to ensure normal bodily functions.Main function of circulatory system that happen through the process called diffusion1. Carry oxygen and nutrients to every cell of the body2. Remove carbon dioxide and other wastes from the cells.Heart- it pumps blood through the blood vesselsPart of the heart1. Right atria- receive blood coming from the body2. Left atria- receive blood coming from the lungs3. Right ventricles- pumps blood to the lungs4. Left ventricles- pumps blood to the body5. Septum divide the heart into left and right 6. Valves- prevent the blood to back flowa. Aortic semilunar valveb. Tricuspid valvec. Pulmonary semilunar valved. Bicuspid valve Blood- also known as the river of life. It transport a variety of essential elements throughout the body.Function: 1. Transportation of dissolved gases, nutrients, and hormones, and metabolic wastes.2. protection against toxins, pathogens and blood loss injuries.3. stabilization of body temperature4. regulation of the ph through the blood buffering system and electrolyte composition of interstitial fluids throughout body.Composition of blood1.Blood cells1. Red blood cells (erythrocytes)- transport oxygen and carbon dioxide using hemoglobin2. White blood cells( leukocytes)- help defend our body from diseasesa. Lymphocyte-active against various pathogens, virus-infected and tumor cellsb. Monocyte- engulfs pathogensc. Eosinophil- active against parasites and allergic reactiond. Basophil- active in allergic reactions and matures like mast cellse. Neutrophil- active against bacteria and fungif. Macrophage- engulfs pathogens and alerts lymphocytes3. Platelets( thrombocytes)- help the blood to clot. from large bone marrow cells called megakaryocytes.4. Plasma- yellowish liquid that is about 92%water.

Blood vessels- carrying the blood throughout the body.Three types of blood vessels1. Arteries- move the blood away from the heart carry oxygenated blood.2. Veins- move the blood towards the heart carry deoxygenated blood. Valve is a flap of tissue that prevent the backflow of the blood3. Capillaries-very small blood vessels connecting Arteries and veins.The lymphatic system Acts as a secondary circulatory system. Bring back the fluids to the bloodstream from the space around the bodys cell. It also helps fighting bacterial and viral infection, Lymph- fluid that leaked from the diffusion into the lymphatic vessels. Lymph tissue are located at different part of the body Tonsil, thymus, lymph node(filled with lymphocytes) , spleen(largest organ of lymphatic system), lymphatic vessel, bone marrow.Body circulationMain idea : blood flows through the body through the two types of circulatory loops. Two parts1. Pulmonary circulation- transport oxygen-depleted blood from the lungs. Main function is to oxygenate the blood2. Systemic circulatory- carries oxygen-rich blood from the heart to the organs and tissues.

Prevention, detection and treatment of diseases of the circulatory system. Disorders of the blood vessels1. Atherosclerosis- associated with cholesterol build up called plaque. Inside of the wall of the arteries.2. Stroke- results from the blockage brought by the hardening of the arteries in the brain or in the neck vessels leading to the brain.a. Thrombus- blood clot fixed within a blood vesselsb. Embolus- wandering clotc. Cerebral haemorrhage- sudden bursts of blood vessels.d. Diseases of the heart1.Coronary Heart Diseases- inability of the heart to reach the coronary arteries of the heart Angina pectoris- painful chest, shoulder and left arm due to CHD Myocardial infarction- technical term for heart attack.2.Hypertinsive Heart Disease elevated blood pressure resulting from the tightening of the arterioles( smallest arteries of the body).3. rheumatic heart diseases= usually occurs in children-result from untreated streptococcus pyogenas bacterial infection causes further damage of the heart known as endocarditis.

Disorders of the blood 1. Haemophilia- the blood does not clot properly. (hemophiliacs or bleeders)2. Anemia- low read blood cell can be treated with iron supplement, iron-rich food and folic acid supplement,3. Leukemia- abnormal increase of white blood cell.