1.The Transport System

2. The Human Heart The Human heart is designed as a pair of side- by-side pumps. Atria: These thin-walled, muscular chambers. Ventricle: Each side also had a thick walled muscular pump. 3. Cardiovascular System The main transport system in humans consist of blood, the heart to pump it and blood vessels through which it is pumped. 4. Vesselss, arteries, and capilaries Three Types of Blood Vessels: 5. Blood Vessels Capillary- site of exchange between blood and body tissue Artery- carries blood under high pressure away from the heart Veins- carries blood under low pressure back the heart. Outer Layer (collagen fiber) absent present present Middle Layer (elastic fibers and involuntary muscle fibers) absent Thick layer Thin layer Valves absent absent present Inner Layer or endothelium (pavement epithelium) present present present 6. Blood Flow Humans have one way blood flow. The Pulmonary circulation is to and from the lungs, which means the blood that is coming from lungs would have plenty of oxygen. Furthermore, blood that is de-oxygenated will contain carbon dioxide. Systemic circulation is to and from all other organs, including the wall of the heart itself. 7. 6.2.1 Draw and label a diagram of the heart showing the four chambers, associated with blood vessels, valves and the route of blood through the heart 8. Video Time http://www.youtube.com/watch?v=PgI80Ue-AMo 9. 6.2.2 State that the coronary arteries supply heart muscle with oxygen and nutrients. Coronary arteries: Coronary circulation is the circulation of blood in the blood vessels of the heart muscle (the myocardium). The vessels that deliver oxygen-rich blood to the myocardium are known as coronary arteries. The vessels that remove the deoxygenated blood from the heart muscle are known as coronary veins. 10. Video http://www.youtube.com/watch?v=qnbUhMogDNI 11. myogenic muscle contraction, the role of of the pacemaker, nerves, the medulla of the brain and epinephrine. Defining Terms: The Medulla Oblongata: the medulla is in the charge of automatic function; relays nerve signals between the brain and spinal cord. Furthermore, this is responsible of cardiac, respiratory, vomiting, and other functions. In relations to heart beat and blood pressure, the medulla controls both functions. Myogenic Muscle Contraction: How arteries and arterioles react to an increase or decrease of blood pressure to keep the flow constant. Epinephrine: a hormone and neurotransmitter that enables to increase heart rate, contracts blood vessels, dilates air passsages, and participate sympathetic response. 12. Continued from the last slide: Beats originate in a structure in the muscle of the wall of the right atrium, called the pacemaker. Special muscle fibers radiate out from the pacemaker, conducting the impulse to the muscles of both atria, triggering contraction there. Ventricular contraction is triggered. After every contraction, cardiace muscle has a period of insensitivity to stimulation, when the heart refills with blood. Did you know that the hearts natural rhythm set by the pacemaker is about 50 beats per minute? 13. Continued from the Last Slide: - The Medulla= the control contre. - When the medulla in our brain sends signals one nerve, it triggers the speeding up of the heart rate, and the other one slows down the speeding. - This opposite effect is called, antagonistic. - Furthermore, adrenaline causes the pacemaker to increase the heart rate. 14. 6.2.6 State that blood is composed of plasma, erthrocytes, leucocytes (phagocytes and lymphoycytes) Component Description Plasma Liquid portion of blood Erthrocytes Red blood cells (carry oxygen and carbon dioxide) Leucocytes White blood cells (phagocytes and lymphocytes) Platelets Cell fragments (assist in blood clotting) 15. Heart Beat 1. Atrium muscle contract, pushing blood past the bicuspid valve into the ventricle. 2. Atrium muscles relax. 3. Ventricle muscles contract, causing blood pressure to close the bicuspid valve and open the semilunar valves, forcing blood into the aorta. 4. Ventricle and atrium muscle relax, while the pressure of blood in the aorta causes the semilunar valves to shut. 5. Blood flows into the atrium and opening the biscupid valve as it starts to flow into ventricle. 16. Valves The purpose: it prevents blood from flowing backward; therefore, maintaining the direction of flow through the heart. Atrio-ventricular valves: large valves, positioned to prevent backflow from ventricles to atria. Atrio-ventricular valve that is on the right side is tricuspid valve, and on the left is the bicuspid. Semilunar valves: a different type of valve separates the ventricles from pulmonary artery (right side) and aorta (left side) 17. 6.2.7 State that the following are transported by the blood: nutrients, oxygen, carbon dioxide, hormones, antibodies, urea, and heat. What is transported What it is or does Nutrient Glucose, amino acids, etc. Oxygen Reactant needed for aerobic cell respiration. Carbon dioxide Waste product of aerobic cell respiration Hormones Transported from glad to target cells Antibodies Protein molecules invovled in immunity Urea Nitrogenous waste (filitered out of the blood by kidneys) Heat Skin arterioles (can change diameter in order to gain or lose heat)