These notes not reviewed by Dr Barstow Chapter 40 Circulatory System Circulatory systems of animals -All animals are heterotrophs, they require the digestion of food. Cells use food for: 1. formation of new cells 2. transferring the food into energy Oxygen is needed in all living cells. All animals require oxygen and molecules of food. Acquisition of Oxygen: 1. Diffusion: living in water with dissolved oxygen. An example is the jellyfish. 2. Cavity: "slosh" around the oxygen all over the organisms internal body. 3. Closed Circulatory system: all the blood and blood cells are contained in vessels, and the blood is circulated through the organism via these blood vessels. 4. Open Circulatory system: there is no distinction between the blood and the organism's body fluids (There are no vessels used in the circulation of blood). Blood -plasma=55% -white blood cells and platelets=less than 1% -red blood cells=45% Composition of blood: A. Plasma 1. mainly water: solvent for carry other molecules throughout the organism. 2. salts -used for pH balance and osmotic balance 3. proteins a. albumin=osmotic balance and pH balance b. fibrinogen=needed for blood clotting c. immunoglobulin=these are the antibodies which fight off infection in the body 4. nutrients a. glucose b. vitamins c. fatty acids d. amino acids 5. Oxygen and Carbon Dioxide 6. Hormones B. Formed Elements 1. Erythrocytes -red blood cells - 5-6 million per cc 2. Leukocytes -white blood cells - 5-10 thousand per cc 3. Platelets Functions of Blood: 1. Respiration: blood takes oxygen to the cells and then takes carbon dioxide to the lungs. 2. Nutrition: transports digested food molecules to the tissues. 3. Excretion: transports water and waste products to the excretory structures. 4. Regulation: blood helps regulate: a. hormones b. water to the kidneys c. body temperature 5. Protection a. clotting b. antibodies c. phagocytes For all of this to work you must have a pump of some kind to help get the blood to all parts of the body. The Heart See Figure 40.14 *Fish have a two-chambered heart. *Frogs because of their terrestrial nature have lungs so their heart has developed a third chamber. *Reptiles almost have a four chamber heart, but there is an opening in the chamber so it is technically considered a three chambered heart. *Birds and mammals both have four chambered hearts. Four Circuits: 1. Pulmonary -Blood travels from the right side to the lungs via the pulmonary artery and back to the left side of the heart. 2. Systemic Circulatory systems a. Upper (head) b. Lower (extremities) 3. Renal -This transports waste and water to the kidneys. 4. Hepatic/Portal -Transports blood to the liver. Aorta is the artery that goes straight to the head. Pulmonary Arculator See Figure 40.15 -Blood travels by way of the pulmonary artery. Two things result form this: 1. Carbon dioxide is expelled 2. Oxygen is taken up by the body Movement of Blood 1. (start) artery 2. arteriole 3. capillaries 4. venule 5. vein 6. heart 7. (start) artery and so on. Veins lead towards the heart and arteries lead away from the heart. Capillaries permeate every part of your body; after gas exchange the blood returns to the heart to be pumped to the lungs so it can be reoxyenegated. -This whole process is controlled by muscles. Precapillary Sphincters -They open and close to control the amount of blood that flows thought the capillaries. -The reason for shock is that all of these sphincters open and blood is filling all of these capillaries. This is why a shock victim has low blood pressure. Structure of the Artery, Vein and Capillary The artery is a very muscular structure. The veins are less muscular, and the capillary is about 1 or 2 cells which, which makes it easier for diffusion of oxygen and nutrients into the body cells. See Figure 40.5 The Heart See Figure 40.16 -Right side pumps to the lungs: The blood comes from the systemic circulatory system then goes into the right ventricle and is forced into the pulmonary artery. -When the heart opens up, the blood is not allowed to come back because of a series of valves. 1. pulmonary valves 2. tricuspid valve 3. mitral valve Dr. Barstow pointed out that smoking is a really bad thing. It adversely affects your health. It is a life-threatening habit, and very difficult to quit; though in your and your loved ones' best interest. The note taker points out that Gilbert Health Center offers a tobacco secession program.
