front 1 Circulatory Systems: | back 1 Larger animals developed circulatory systems to transport oxygen and nutrients quickly across greater distances. |
front 2 Specialized Respiratory Surfaces: | back 2 Larger surface areas in organs like lungs or gills help maximize gas exchange efficiency over small distances. |
front 3 Cnidarians, like the moon jelly in Figure 42.2 in your text, and
planarians do | back 3 Cnidarians and planarians maximize direct diffusion by being thin or having cells close to their environment. This eliminates the need for a circulatory system. |
front 4 Larger animals must have a circulatory system to move fluid between
cells and the outside | back 4 A circulatory fluid (blood or hemolymph), a set of vessels, and a pump (heart). |
front 5 What is hemolymph? | back 5 Hemolymph is the fluid in animals with an open circulatory system, combining blood and interstitial fluid |
front 6 Contrast open circulatory systems with closed circulatory systems. | back 6
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front 7 Artery | back 7 Carries blood away from the heartThick muscular walls |
front 8 Arteriole | back 8 Distributes blood to capillariesSmaller, with smooth muscle |
front 9 Vein | back 9 VeinReturns blood to the heartThin walls, often with valves |
front 10 Venule | back 10 Collects blood from capillariesThin-walled, leading to veins |
front 11 Capillary | back 11 Site of exchangeThin-walled, single-cell thickness |
front 12 Atria | back 12 Receive blood returning to the heart. |
front 13 Ventricles | back 13 Pump blood out of the heart. |
front 14 Single Circulation | back 14 Blood flows through the heart once per cycle, as in fish. |
front 15 Double Circulation | back 15 Blood passes through the heart twice, allowing separate pulmonary and systemic circuits, as in mammals and birds. |
front 16 In a circulatory system, exchange occurs in two general places. Blood
goes to a respiratory | back 16 Exchange occurs in capillaries where blood meets tissues |
front 17 Fish | back 17 Two-chambered heart; single circulation; blood oxygenated in gills. |
front 18 Amphibians | back 18 Three-chambered heart; partial separation in double circulation; some mixing of oxygenated and deoxygenated blood. |
front 19 Mammals | back 19 Four-chambered heart; complete double circulation; full separation ensures efficient oxygen delivery |
front 20 Why is a four-chambered heart a key adaptation required for endothermy? | back 20 It allows separate pulmonary and systemic circulation, supplying high oxygen levels for metabolic demands of endothermy. |
front 21 Use the four-chambered heart of birds and mammals to explain the
concept of convergent | back 21 Birds and mammals independently evolved four-chambered hearts, a convergence enabling higher metabolic rates required by endothermic life. |
front 22 Cardiac Cycle | back 22 Sequence of heart contraction and relaxation. |
front 23 Systole | back 23 Heart chambers contract, pumping blood. |
front 24 Diastole | back 24 Heart chambers relax, filling with blood. |
front 25 Cardiac Output | back 25 Volume of blood pumped per minute, dependent on heart rate and stroke volume. |
front 26 Atrioventricular Valves | back 26 Prevent backflow from ventricles to atria. |
front 27 Semilunar Valves | back 27 Prevent backflow from arteries to ventricles. |
front 28 Sinoatrial Node and Cardiac Cycle | back 28 The SA node initiates electric impulses, coordinating heart rhythm. Each blue mark in the cardiac cycle represents phases from atrial contraction to ventricular filling. |
front 29 How do structure and function correlate in the capillaries? | back 29 Capillaries’ thin walls allow efficient nutrient and gas exchange between blood and tissues. |
front 30 What anatomical feature of the veins maintains a unidirectional flow
of blood back toward | back 30
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front 31 As blood vessel diameter decreases, blood velocity will ____________ | back 31 decreases |
front 32 Why does blood slow as it moves from arteries to arterioles to
capillaries? Why is this | back 32 Slowdown is crucial for efficient gas and nutrient exchange in capillaries |
front 33 Explain the exchange of fluid at the two ends of a capillary by
annotating this figure. Include | back 33 Blood Pressure forces fluid out at the capillary’s arterial end; Osmotic Pressure draws fluid back at the venous end. |
front 34 Why does the presence of blood proteins tend to pull fluid back into the capillaries? | back 34 Blood proteins increase osmotic pressure, pulling fluid back into capillaries to balance fluid exchange |
front 35 The capillaries “leak” about 4 L of fluid each day. How is this returned to the blood? | back 35
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front 36 What is lymph? Is it more like blood or more like interstitial fluid? | back 36 resembles interstitial fluid, containing some white blood cells but fewer proteins than blood |
front 37 We don’t have a second heart to pump lymph. What keeps lymph moving along? | back 37
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front 38 Blood separates into two components, a liquid matrix called
________________ and the | back 38 Plasma is the liquid matrix in which cells are suspended |
front 39 List the cellular elements of blood and give their general functions | back 39
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front 40 Describe three ways in which the structure of an erythrocyte enhances
its function, which is | back 40 Shape (biconcave) for increased surface area, no nucleus for maximum hemoglobin, and flexibility to navigate capillaries. |
front 41 What is the role of hemoglobin? What mineral is required to make it? | back 41 Hemoglobin binds oxygen; iron is essential for its function |
front 42 How does sickle-cell disease affect the ability of the respiratory
system to deliver oxygen and | back 42 Abnormally shaped red cells impede oxygen transport, leading to insufficient oxygen delivery |
front 43 Where are blood stem cells found? | back 43 bone marrow. |
front 44 Blood Clotting Mechanism | back 44
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front 45 Plaque | back 45 from fats and cholesterol narrows arteries. |
front 46 Heart Attack | back 46 Blocked coronary arteries; Stroke: Blocked brain arteries. |
front 47 LDLs | back 47 transport cholesterol to cells (can lead to plaque); HDLs remove excess cholesterol. |
front 48 Hypertension | back 48 damages vessels, increasing risk of heart disease. |
front 49 Gas exchange with water as the respiratory medium is much more
demanding than exchange | back 49 Water has lower oxygen, higher density, and viscosity, making gas exchange more energy-intensive. |
front 50 There are several requirements for a respiratory surface. It must be
moist, have a large | back 50 Gills, tracheae, lungs, and skin can serve as moist respiratory surfaces |
front 51 Countercurrent Exchange in Gills | back 51 Countercurrent flow maximizes oxygen absorption as water and blood flow in opposite directions across gill capillaries. |
front 52 Oxygen Absorption Without Countercurrent Exchange | back 52
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front 53 What is the most common respiratory structure among terrestrial
animals? What groups have | back 53
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front 54 Mammalian Respiratory Anatomy | back 54 The pharynx channels air to the larynx and trachea, splitting into bronchi and narrowing to bronchioles, ending in alveoli for gas exchange |
front 55 explain how negative pressure breathing occurs in mammals | back 55 Diaphragm contraction expands the chest cavity, reducing pressure and drawing air into the lungs. |
front 56 explain the homeostatic control of breathing | back 56 Increased CO₂, not O₂ levels, triggers the respiratory rate to prevent acidosis. |
front 57 n general, what has a greater effect on the rate of | back 57 High CO₂ levels primarily increase respiration to remove excess carbon dioxide and maintain pH |
front 58 Oxygen and CO₂ Path from Inhalation to Exhalation | back 58 Oxygen travels from alveoli to blood, to tissues, then CO₂ moves from tissues to blood, finally exhaled through the alveoli |
front 59 What is the respiratory pigment in vertebrates? | back 59 Hemoglobin |
front 60 Hemoglobin is a protein with quaternary structure. How many subunits
does it have? What is | back 60 Hemoglobin has four subunits, each with iron that binds oxygen. |
front 61 Where does the constant production of carbon dioxide originate
and | back 61 Cellular respiration produces CO₂, transported in blood and removed through the lungs. |