The Circulatory System The circulatory system includes the Heart, Blood Tissue and the Blood Vessels.
The Circulatory System-Transport The absorption and circulation of materials throughout an organism
What does the circulatory system do? (What is its function?) 1. Delivers food and oxygen to body cells. 2. Carries carbon dioxide and other waste products away from cells. Movement of materials into and out of cells occurs by diffusion (from an area of high concentration to low concentration no energy required) Movement also occurs by active transport (from an area of low concentration to high this requires energy and transport proteins)
** In general, the blood is a fluid tissue helping to maintain homeostasis for all cells in the body. Transport of needed substances to body cells. (oxygen, amino acids, glucose, fatty acids, glycerol, salts, etc.)
The heart functions as a double pump beating in unison. 1. Pumps Deoxygenated blood (relatively low in oxygen) to lungs 2. Pumps Oxygenated blood (relatively high in oxygen) to body cells. ** Heartbeat is stimulated by an electrochemical impulse. Pacemaker - in the right atrium - initiates the heartbeat
3. Transport of wastes from cells. (urea, water, carbon dioxide in the form of the bicarbonate ion) 4. Helps to maintain a constant body temperature. 5. Aids the body in fighting disease.
The Human (Mammalian) Heart Structure Vocabulary 1. septum: muscular central wall dividing the mammalian heart into two halves 2. atria: thin walled upper heart chambers which receive blood pump blood to the ventricles 3. Ventricles: muscular thick walled chambers which pump blood from the heart -- the lower chambers 4. Valves - prevent the backward flow of blood in the heart
Blood Vessels 1. Arteries --carry blood away from the heart --usually spurt blood when cut --all except the pulmonary artery carry oxygenated blood --thick walled and elastic pulse: expansion and contraction of the artery walls in response to the heartbeat
2.Veins --carry blood toward the heart --contain valves --closer to the body surface than the arteries --all except the pulmonary vein carry deoxygenated blood --thinner, less muscular and elastic than arteries --depend upon muscle and diaphragm movements for blood flow
Capillaries --most numerous vessels --connect arteries to veins --microscopic, one cell thick walls --site of much exchange between the blood and the intracellular fluid (lymph) by diffusion
Lymph vessels -have walls one cell thick -present around all body cells -Lymph composition is similar to that of blood except for the absence of RBC and some plasma proteins. -chief site of material exchange with the tissues
Major lymph vessels have lymph nodes which contain phagocytic white blood cells which filter bacteria and dead cells from the lymph. Valves are present in some lymph vessels--aiding in the movement of the lymph. Respiratory movements also aid lymph flow.
Which Way Did it Go?
Blood Pressure
Causes of High Blood Pressure implicated: 1. excess sodium intake (salt!) 2. stress 3. cigarettes (nicotine) 4. saturated fats 5. alcohol & caffeine 6. obesity 7. heredity & aging No cure--may be treated by medication & diet. "Silent killer"--millions don't know they have it
Blood Blood = a connective tissue made up of blood cells and a liquid called blood plasma. About 7 % of your body mass About 4.5-5.6 Liters in an adult human Men = 5.6 Liters Women = 4.5 Liters Pregnant woman = 5.0 Liters
The Parts of Blood 1. Plasma =carries everything 2. Red Blood Cells =(RBC) gas exchange 3. White blood Cells =(WBC) fight infection 4. Platelets = clotting
Components of Blood
Blood Composition Plasma 55% (liquid part of the blood); Blood Cells 45%
55% plasma 45 % RBC, WBC and platelets
BLOOD CELL TYPES Red Blood Cells: most numerous biconcave disc shaped smaller than white blood cells, larger than platelets no nucleus when mature produced in the red marrow of long bones destroyed in the liver and spleen contain the iron protein compound HEMOGLOBIN whose chief function is to combine with oxygen and carry it to the cells
White blood cells AKA- Lymphocytes or Leukocytes White blood cells are larger than red blood cells, but there are less of them. 8000 in one drop of blood Function of White Blood Cells surround and digest bacteria Attack bacteria and viruses **Pus = WBC + dead bacteria YouTube - White Blood Cell Chases Bacteria
White Blood cells CONTINUED --largest blood cells--several different types --about 8,000 per drop of blood --most are formed in the bone marrow or in the lymph tissue --most protect the body against diseases by forming antibodies or by engulfing bacteria
Main White Blood Cell Types 1. Phagocytes-- engulf bacteria and viruses by phagocytosis --able to leave the bloodstream and move between the cells of the body by squeezing through the capillary walls
2. Lymphocytes - produce antibodies which clump bacterial poisons or bacteria (antigens) (antigens-- foreign substances in the body)
Platelets Bits of cells Live for approximately 10 days Function of Platelets creates fibrin = enzyme that helps clot blood (tiny threads seal cuts)
3. Platelets --smallest blood cells (fragments) --150,000 to 300,000 per drop of blood --needed for clotting
Clotting: Involves a series of enzyme controlled reactions resulting in the formation of protein fibers that trap blood cells and form a clot.
Pacemaker- Uses electrical impulses from wire leads inserted into the Heart. Keeps the Heart in perfect rhythm.
Diseases & Disorders of the Circulatory System Myocardial Infarction- heart attack Hypertension- high blood pressure Hypotension- low blood pressure Stroke- clot in the brain Angina Pectoris- severe pain in chest Sickle Cell Anemia- sickle shaped rbc s (genetic) Pernicious Anemia- very low rbc count MVP- prolapsed mitral valve Pericarditis- inflammation of outer membrane covering the heart Leukemia- cancer of the blood, elevated wbc count Varicose veins- enlargement of veins Arrhythmias- irregularities in heart rhythm Endocarditis- inflammation of inner lining of heart Cardiomyopathy- weakening of the heart muscle Hemophilia- no clotting factor in the blood