Circulation & Gas Exchange
42.1 Circulatory Systems link exchange surfaces with cells throughout the body
42.2 Coordinated cycles of heart contraction drive double circulation in mammals
42.3 Patterns of blood pressure and flow reflect the structure and arrangement of blood vessels
42.4 Blood components function in exchange, transport, and defense
42.5 Gas exchange occurs across specialized respiratory surfaces
42.6 Breathing ventilates the lungs
42.7 Adaptations for gas exchange include pigments that bind and transport gases
Terms : Hide Images
| 338750483 | Circulatory system | has three basic components: circulatory fluid, set of interconnecting vessels, and a muscular pump, the heart | |
| 338750484 | Open circulatory system | circulatory fluid bathes the organs directly | |
| 338750486 | Hemolymph | Also the interstitial fluid. Bathes body cells in open circulatory system | |
| 338750488 | Closed circulatory system | a circulatory fluid, blood, is confined to vessels and is distinct from the interstitial fluid | |
| 338750490 | Cardiovascular system | Blood circulates to and from the heart through extensive network of vessels | |
| 338750492 | Arteries | carry blood away from the heart to organs throughout the body | |
| 338750494 | Arterioles | small vessels that convey blood to the capillaries | |
| 338750496 | Capillaries | microscopic vessels with very thin, porous walls | |
| 338750498 | Capillary beds | network of capillaries, infllitrate every tissue, passing within a few cell diameters of every cell in the body. | |
| 338750500 | Venules | Capillaries converge on their "downstream" end | |
| 338750502 | Veins | Venules lead into veins. Veins are the vessels that carry blood back to the heart. | |
| 338750504 | Atria (singular atrium) | The chamber that receive blood entering the heart | |
| 338750506 | Ventricles | The chambers responsible for pumping blood out of the heart. | |
| 359018628 | Coronary arteries | Short circuit blood vessel which service the heart muscle. | |
| 338750507 | Single circulation | Fish, rays, sharks. Two chamber heart (atrium & ventricle). Blood passes through the heart once in each complete circuit. | |
| 338750509 | Double circulation | Amphibians, reptiles, mammals. The pumps for the two circuits are combined into the heart. One pump delivers oxygen-poor blood to the lungs. The next pump receives oxygen-rich blood from the lungs and delivers it to body tissues. | |
| 338750511 | Pulmonary circuit | First pump of the heart delivers oxygen-poor blood to capillary beds in the lungs | |
| 338750513 | Pulmocutaneous circuit | Amphibians. First pump of the heart delivers oxygen-poor blood to capillary beds in the lungs AND skin | |
| 338750515 | Systemic circuit | Blood exchanges oxygen for carbon dioxide in the tissues and returns to the right atrium. | |
| 338750517 | Cardiac cycle | One complete sequence of pumping and filling of the heart | |
| 338750519 | Systole | The contraction phase of the cardiac cycle | |
| 338750521 | Diastole | The relaxation phase of the cardiac cycle | |
| 338750523 | Cardiac output | The volume of blood each ventricle pumps per minute. Determined by heart rate and stroke volume. Average 5 L/min | |
| 338750524 | Heart rate | rate of contraction (number of beats per minute) | |
| 338750525 | Stroke volume | amount of blood pumped by a ventricle in a single contraction | |
| 338750526 | Atrioventricular valve | lies between each atrium and ventricle | |
| 338750527 | Semilunar valve | located at the two exits of the heart: Where the aorta leaves the left ventricle and where the pulmonary artery leaves the right ventricle | |
| 338750528 | Heart murmur | blood squirts backward through a defective valve, it may produce and abnormal sound | |
| 338750529 | Sinoatrial (SA) node | Pacemaker. set the rate and timing at which all cardiac muscle cells contract | |
| 338750530 | Electrocardiogram (ECG or EKG) | Record currents generated by the SA node which can be used to monitor heart rate. | |
| 338750531 | Atrioventricular (AV) node | Receiver for impulses generated by the SA node. Signal from the AV node are conducted to the heart apex and throughout the ventricular walls causing contraction. | |
| 359018629 | Hemoglobin | Increases solubility of O2. Can bind up to 4 O2 molecules, one at each heme group. Absorption or release of O2 depends on partial pressure, high in lungs, low in tissue. Cooperative binding. | |
| 359018630 | Cooperative binding | Increases binding in hemoglobin. After one O2 molecule binds, Hb group conformation changes making it easier for next to bind. | |
| 359018631 | Transport of CO2 | CO2 diffuses into blood and is converted to bicarbonate (CO2) + (H20) --> (CHO3-) + (H+) (Carbonic anhydrase). Process is reversed in lungs. Some CO2 binds to hemoglobin. | |
| 359018632 | Bohr Effect | Conversion of CO2 to carbonate produces H+, lowers blood pH. H+ binds to hemoglobin in place of O2. Lowers partial pressure at tissue, more O2 delivered during exercise. | |
| 359018633 | Myoglobin | Found in muscles, highest affinity for oxygen at very low partial pressures. Works as oxygen reserve. | |
| 359018634 | Breathing regulation | More sensitive to changes in pCO2. Regulated by the medulla. Regulates by sensing homeostasis 7.4 pH blood. pH affected by bicarbonate conversion. Carotid and aortic bodies sensitive to pO2. | |
| 359018635 | Ventilation | Moves the respiratory medium over the respiratory surface | |
| 359018636 | Concurrent exchange | Blood flows in the opposite direction to water passing over gills. Blood flows in direction of increasing partial pressure. | |
| 359018637 | Tracheal System | Found in insects, consists of branching tubes that service the body cells directly. | |
| 359018638 | Cardiovascular disease | Account for more than half of US deaths. | |
| 359018639 | Atherosclerosis | Build up of plaque deposits in the arteries | |
| 359018640 | Cholesterol | Low density lipoproteins (LDL) aid in membrane production where as high density lipoproteins (HDL) return it to heart. High LDL/HDL ratio is risk of heart attack. | |
| 359018641 | Inflammation | plays a role in atherosclerosis: Aspirin inhibits inflammation and reduces the risk of heart attacks and stroke | |
| 359018642 | Hypertension | High blood pressure, promotes atherosclerosis and increases the risk of heart attack and stroke. Can be reduced by dietary changes, exercise, and/or medication. | |
| 359018643 | Heart Attack | Death of cardiac tissue from from blockage of coronary arteries | |
| 359018644 | Stroke | death of brain resulting from rupture or blockage of arteries in the head | |
| 359018645 | Angina pectoris | caused by partial blockage of the coronary arteries and results in chest pains |
