Circulatory

    Cards (219)

    • What essential substances do animals require to survive?
      Oxygen and carbon dioxide
    • How do small organisms meet their transport needs?
      Through diffusion due to their large surface area to volume ratio
    • What happens to the surface area to volume ratio as the size of an organism increases?

      It decreases
    • Why does diffusion become insufficient in larger organisms?

      Because diffusion distance increases and metabolic rate increases
    • What are the features of a mass transport system?

      1. A network to move through (e.g., vessels)
      2. A medium for movement (e.g., blood)
      3. Controlled direction (e.g., pressure gradient created by the heart)
      4. Maintenance of speed (e.g., contraction of the heart and elastic recoil of arteries)
    • What type of molecule is water?

      A polar molecule
    • Why is water considered a polar solvent?

      Because it can dissolve many biological molecules
    • What role does hydrogen bonding play in water transport through xylem vessels?

      It creates cohesion and adhesion
    • What is the significance of water's high heat specific capacity?

      It minimizes temperature fluctuations in living organisms
    • What are the main types of blood vessels?
      • Arteries
      • Veins
      • Capillaries
    • What is the primary function of arteries?

      To carry oxygenated blood to the body tissues
    • Why do arteries have a small lumen?

      To maintain high blood pressure
    • What is the function of smooth muscle in arteries?

      To control the diameter of blood vessels
    • What do veins carry?

      Deoxygenated blood to the lungs
    • Why do veins have a large lumen?

      To minimize resistance to flow
    • What is the purpose of valves in veins?

      To prevent backflow of blood
    • What is the structure of capillaries?

      Very small with a narrow lumen
    • Why is the endothelium of capillaries one cell thick?

      To maintain a short diffusion distance
    • What are the main components of the heart and cardiac cycle?
      1. Four chambers: right and left atria, right and left ventricles
      2. Four main blood vessels: pulmonary vein, aorta, vena cava, pulmonary artery
      3. Atrioventricular valves: mitral and tricuspid/bicuspid
      4. Semilunar valves: pulmonary and aortic
      5. Tendinous chords: prevent atrioventricular valves from turning inside out
      6. Septum: prevents mixing of oxygenated and deoxygenated blood
      7. Coronary arteries: supply blood to cardiac muscle
      8. Cardiac muscle: thicker on the left side
    • What are the stages of the cardiac cycle?
      1. Atrial systole: atria contract, forcing blood into ventricles
      2. Ventricular systole: ventricles contract, blood leaves through aorta and pulmonary artery
      3. Cardiac diastole: heart relaxes, pressure decreases, semilunar valves close
    • What is atherosclerosis?

      The hardening of arteries due to plaque build-up
    • What causes atheroma formation?

      Damage to the endothelium and subsequent build-up of substances
    • What is the role of white blood cells in atherosclerosis?

      They move into the artery in response to inflammation
    • How does plaque formation affect blood flow?

      It narrows the artery and restricts blood flow
    • What are the risk factors for atherosclerosis?

      • Genetics
      • Age
      • Diet
      • Gender
      • High blood pressure
      • High cholesterol levels
      • Smoking
      • Physical inactivity
      • Obesity
    • How can the risk of cardiovascular disease (CVD) be reduced?

      By stopping smoking, exercising regularly, and maintaining a healthy diet
    • What are some cardiovascular diseases caused by atherosclerosis?

      Angina, stroke, myocardial infarction, and aneurysms
    • What is thrombosis?

      Blood clotting that prevents blood loss and entry of microorganisms
    • What are the steps in the blood clotting process?
      1. Platelets attach to exposed collagen fibers
      2. Thromboplastin is released, converting prothrombin to thrombin
      3. Thrombin converts fibrinogen to fibrin
      4. Fibrin forms a network trapping platelets and red blood cells
    • What is energy balance?

      The balance of calories consumed versus calories burned
    • What happens if more calories are burned than consumed?

      It leads to weight loss
    • How is BMI calculated?

      By dividing body mass in kilograms by height in meters squared
    • What does a BMI value below 18 indicate?

      That the individual is underweight
    • What does a BMI value above 30 indicate?

      That the individual is obese
    • What essential substances do animals require to survive?
      Oxygen and carbon dioxide
    • How do small organisms meet their transport needs?
      Through diffusion due to large surface area
    • What happens to the surface area to volume ratio as organism size increases?
      It decreases
    • Why does diffusion become insufficient in larger organisms?
      Because diffusion distance increases and metabolic rate rises
    • What is a mass transport system in larger organisms composed of?
      Heart and circulation
    • What are the features of a mass transport system?
      1. A network to move through (e.g., vessels)
      2. A medium for movement (e.g., blood)
      3. Controlled direction for substance movement
      4. Maintenance of speed through heart contraction
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