Bio 1215- Chapter 14

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  1. exchange surfaces must be _____ for gas exchange.
  2. _____________ --->better diffusion
    more surface area
  3. how do small animals and complex animals exchange gas?
    • small animals: body surface for gas exchange
    • complex animals: need a transport system to minimize diffusion distance
  4. what are 3 transport systems used by complex animals to minimize diffusion distance?
    • gastrovascular cavity
    • open circulatory systems
    • closed circulatory systems
  5. how does the gastrovascular cavity minimize diffusion distance for complex animals? (2)
    • exposes more cells to the "outside"
    • may be multi-branched
    • allows for more surface area= better diffusion
  6. briefly describe the open circulatory system. Give an example of some organisms.
    • hemolymph (instead of blood) leaves vessel and enters open areas called sinuses
    • arthropods and most molluscs
  7. describe close circulatory systems. what are some organisms with open circulatory systems.
    • blood confined to vessels
    • annelids, cephalopods, vertebrates
  8. what are the 2 chambers in the heart called and what are their functions?
    • 1,2 atria (receive blood)
    • 1,2 ventricles (pumps the blood to lungs and rest of body)
  9. where does blood go after entering the atria?
    --> ventricles --> arteries--> arterioles-->capillaries-->venules--> veins--> atria
  10. describe the circulatory system of fish. (2)
    • single circulation
    • heart has 1 atrium, 1 ventricle
  11. describe the circulatory system of amphibians. (3)
    • double circulation
    • 2 atria, 1 ventricle
    • oxygenated and deoxygenated blood mix in ventricle
  12. describe the circulatory system of reptiles.
    3 chambers but have partial septum (less mixing of oxygenated and deoxygenated blood)
  13. describe the circulatory system of mammals or birds. (2)
    • 2 atria; 2 ventricles
    • separate pulmonary and systemic circulations
  14. what are the walls of the heart made of and how are the cells connected?
    • walls mostly of cardiac muscle
    • cells connected by gap junctions into 2 networks; atrial and ventricular
  15. how do the heart chambers in the heart contract?
    both atria contract at once, then both ventricles
  16. what are the 2 types of valves in the heart and what are their functions?
    • 2 atrioventricular valves prevent backflow into atria
    • 2 semilunar valves prevent backflow into ventricles
  17. define the cardiac cycle.
    sequence of events around one heart beat
  18. in humans, what is the average beats/min at rest?
  19. in smaller animals, the heart rate is ______.
  20. compare systole and diastole.
    • systole: ventricular contraction
    • diastole: ventricular relaxation
  21. what is the pacemaker of the heart and where is it located?
    • sinoatrial (SA) node
    • in wall of right atrium
  22. describe the routes of the electrical signals of the heart and how the heart contracts.
    • contraction begins at SA node
    • wave of contraction spreads through atria
    • blood pumped to ventricles
    • excitation reaches atrioventricular (AV node)
    • travels to heart apex along branch bundles
    • spreads upwards through the ventricles along purkinje fibers
    • ventricular contraction pushes blood up towards lungs and aorta
  23. heart rate and stroke volume regulated by what 2 systems?
    nervous system and endocrine system
  24. what are the 3 layers in artery and vein walls?
    • endothelium
    • smooth muscle
    • connective tissue
  25. between artery and vein, which is thicker and why?
    artery walls thicker due to more smooth muscle
  26. what layers do capillaries have and why?
    capillaries have only endothelium because minimizes diffusion distance
  27. blood moves mostly due to what?
    pressure created by heart
  28. pressure decreases to ______ in veins.
  29. what are 2 ways that blood pressure is adjusted?
    changing vessels diameters and blood volumes
  30. why does blood pressure decrease farther from the heart?
    blood pressure slows down because total diameter of all the vessels increases
  31. If venous pressure is zero, why does the blood return to the heart? (3)
    • valves ensure one way flow
    • veins squeezed by skeletal muscles
    • pressure changes in the thorax during breathing
  32. what is the function of the capillaries?
    exchange of fluids, gases, nutrients and wastes between blood and interstitial fluid (and then body cells)
  33. local control of blood flow to capillaries is via __________________.
    sphincters around arterioles
  34. exchange at capillaries is due to what 3 things?
    • diffusion
    • active transport
    • bulk flow
  35. define bulk flow.
    • at upstream end, fluid pushed out of capillaries by blood pressure (big solutes stay in vessels)
    • at downstream end, most fluid returns due to osmotic pressure
  36. what is the function of lymphatic system, where is lymph returned?
    • lymphatic system collects "leftover" interstitial fluid
    • lymph returned to venous blood flow near collar bones
  37. what is leftover interstitial fluid called?
  38. where do viruses and bacteria attack?
    lymph nodes
  39. what is the pH of blood?
  40. describe the components of blood.
    • made of connective tissue
    • cells (dead and living) =formed elements, in a liquid matrix= plasma
  41. what is plasma mostly made of and what are its components?
    • 90% water + electrolytes=dissolved inorganic ions
    • +plasma proteins= buffers, clotting factors, lipid-transporters
    • +gases, nutrients, wastes, hormones
  42. what are electrolytes?
    dissolved inorganic ions
  43. what are plasma proteins?
    buffers, clotting factors, lipid-transporters
  44. what do electrolytes, plasma proteins, gases, nutrients, wastes, hormones help with?
    help maintain osmotic balance with interstitial fluid
  45. what are the 2 components of formed elements in blood?
    • erythrocytes: red blood cells
    • leukocytes: white blood cells
  46. what is the function of erythrocytes and how is this process done?
    • transport some oxygen and some carbon dioxide
    • oxygen binds to hemoglobin
  47. where are erythrocytes produced and what makes them "dead" cells?
    • produced in red bone marrow
    • lose nucleus and last only 3-4 months
  48. what is a characteristic about leukocyte and where is it produced?
    • when functional, their true living cells
    • produced in bone marrow 
  49. what is the function of leukocytes?
    immune and defensive functions 
  50. what happens to leukocytes during infections?
    leukocytes number increases 
  51. what are the 4 specific types of functions for leukocytes?
    antibodies, histamine, phagocytosis, cell killers 
  52. what are platelets and what are its functions?
    • cell "pieces" (not alive)
    • involved in clotting
    • forms a mesh that traps formed elements 
  53. What are the 3 steps in clotting?
    • cascade of reactions
    • fibrinogen (water soluble)
    • fibrin (insoluble)
  54. what are some characteristics for a great respiratory surface for gas exchange? (4)
    • moist
    • thin
    • large surface area
    • rich blood supply 
  55. what are the 3 structure for gas exchange?
    • gills
    • trachea
    • lungs
  56. define gills. (2) which way does they blood flow in gills?
    • gills= outward extensions of body surface for gas exchange 
    • often sheltered,may be ventilated (for water to pass though)
    • blood flows counter-current to the water
  57. what is a trachea? (2) which organisms use this for gas exchange?
    • air tubes leading inwards from surface holes (spiracles)
    • tubes come into contact with almost all cells
    • insects
  58. what is a lung and what is its function?
    • vascularized invaginations of body surfaces 
    • circulatory system transports gases between the lungs and the body's cells 
  59. In the mammalian respiratory system, how is are freshened and how is it controlled?
    • air freshened by ventilation
    • controlled by nervous system by monitoring pH 
  60. Describe the respiratory system of a bird. where does gas exchange take place?
    • one way air flow through lungs; via bellow-like air sacs
    • gas exchange at parabronchi (not alveoli)
  61. where is oxygen found in the blood?
    99% attached to heme of hemoglobin, 1% dissolved in plasma
  62. what are 2 characteristics of oxygen in blood?
    • not very soluble in water 
    • most bound to respiratory pigments 
  63. what are 3 characteristics about carbon dioxide?
    • 7% dissolved directly in plasma 
    • 23% bound to globin of hemoglobin
    • 70% in the form of dissolved bicarbonate ions (HCO3)
  64. arthropods and molluscs use _____________ to transport gases in blood.
    hemocyanin (dissolved in the plasma)
  65. Vertebrates use _______________ to transport gases in blood.
  66. what are the 4 adaptations diving mammals have for gas exchange?
    • greater blood volume (more hemoglobin)
    • large spleen (stores erythrocytes)
    • high myoglobin levels
    • diving reflex: shunts blood to vital organs 
  67. ___________ stores oxygen in muscle cells.
Card Set
Bio 1215- Chapter 14
circulation and gas exchange
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