knowt ap exam guide logo

Circulatory Systems

  • Exchange of Materials

    • Animal cells exchange material across their cell membrane

      • Fuels for energy

      • Nutrients

      • Oxygen

      • Waster

    • 1-cell organism

      • Diffusion

  • Overcoming the limits of diffusion

    • Diffusion is not adequate for moving material across more than 1-cell barrier

  • In Circulation

    • What needs to be transported

      • Nutrients and fuels

        • From digestive system

      • Respiratory gases

        • O2 and CO2 to and from gas exchange systems

          • Lungs

          • Gills

      • Intracellular waste

        • Waste products from cells

          • Water

          • Salts

          • Nitrogenous wastes

Urea

  • Protective agents

    • Immune defenses

      • White blood cells

      • Antibodies

    • Blood clotting agents

    • Regulatory molecules

      • Hormones

  • Circulatory Systems

    • All animals have:

      • Circulatory fluid

        • Blood

      • Tubes

        • Blood vessels

      • Muscular pump

        • Heart

  • Open Circulatory System

    • Taxonomy

      • Invertebrates

        • Insects

        • Arthropods

        • Mollusks

    • Structure

      • No separation between blood and interstitial fluid

        • Hemolymph

  • Closed Circulatory System

    • Taxonomy

      • Invertebrates

        • Earthworms

        • Squid

        • Octopuses

      • Vertebrates

    • Structure

      • Blood confined to vessels and separate from interstitial fluid

        • 1 or more hearts

        • Large vessels to smaller vessels

        • Material diffuses between blood vessels and interstitial fluid

  • Adaptations in a Closed System

    • Number of heart chambers differs

  • Evolution of a 4-chambered Heart

    • Selective forces

      • Increased body size

        • Protection from predation

        • Bigger body = bigger stomach for herbivores

      • Endothermy

        • Can colonize more habitats

      • Flight

        • Decrease population and increase prey capture

    • Effect of higher metabolic rate

      • Greater need for energy, fuels, oxygen, and waste removal

        • Endothermic animals need 10x more energy

        • Need to deliver 10x fuel and oxygen to cells

  • Vertebrate Cardiovascular System

    • Chambered heart

      • Atrium

        • Receive blood

      • Ventricle

        • Pump blood out

      • Blood vessels

        • Arteries

          • Carry blood away from heart

        • Veins

          • Return blood to heart

        • Cappilarries

          • Thin wall

          • Exchange/diffusion

Capillary beds = networks of capillaries

  • Arteries

    • Built for high pressure pump

    • Thicker walls

      • Provide strength for high pressure pumping of blood

    • Narrow diameter

    • Elasticity

      • Elastic recoil helps maintain blood pressure even when the heart relaxes

  • Veins

    • Built for low pressure flow

    • Thinner-walled

    • Wider diameter

      • Blood travels back to the heart at a low velocity and pressure

      • Lower pressure

        • Distant from heart

        • Blood must flow by skeletal muscle contractions when we move

          • Squeeze blood through veins

      • Valves

        • In larger veins, there are one-way valves that allow blood to flow only toward the heart

  • Capillaries

    • Built for exchange

    • Very thin walls

      • Lack 2 outer wall layers

      • Only endothelium

        • Enhances exchange across capillaries

      • Diffusion

        • Exchange between blood and cells

  • Lymphatic System

    • Parallel circulatory system

      • Transports white blood cells

        • Defending against infection

      • Collects interstitial fluid and returns blood

        • Maintains volume and protein concentration of blood

        • Drains into circulatory system near the junction of the vena cava and right atrium

  • Heart Valves

    • 4 valves in the heart

      • Flaps of connective tissue

      • Prevent backflow

    • Atrioventricular valve

      • Between atrium and ventricle

      • Keeps blood from flowing back into atria when ventricles contract

    • Semilunar valves

      • Between ventricle and arteries

      • Prevent backflow from arteries into ventricles while they are relaxing

  • Heart Sounds

    • Closing of valves

      • “Lub”

        • Recoil of blood against close atrioventricular valves

      • “Dub”

        • Recoil of blood against the semilunar valves

    • Heart murmur

      • Defect in valves cause hissing sound when a stream of blood squirts backward through the valve

  • Cardiac Cycle

    • 1 complete sequence of pumping

      • Heart contracts and pumps

      • Heart relaxes and chamber fill

      • Contraction phase

        • Systole

        • Ventricles pump blood out

      • Relaxation phase

        • Diastole

        • Atria refill with blood

Circulatory Systems

  • Exchange of Materials

    • Animal cells exchange material across their cell membrane

      • Fuels for energy

      • Nutrients

      • Oxygen

      • Waster

    • 1-cell organism

      • Diffusion

  • Overcoming the limits of diffusion

    • Diffusion is not adequate for moving material across more than 1-cell barrier

  • In Circulation

    • What needs to be transported

      • Nutrients and fuels

        • From digestive system

      • Respiratory gases

        • O2 and CO2 to and from gas exchange systems

          • Lungs

          • Gills

      • Intracellular waste

        • Waste products from cells

          • Water

          • Salts

          • Nitrogenous wastes

Urea

  • Protective agents

    • Immune defenses

      • White blood cells

      • Antibodies

    • Blood clotting agents

    • Regulatory molecules

      • Hormones

  • Circulatory Systems

    • All animals have:

      • Circulatory fluid

        • Blood

      • Tubes

        • Blood vessels

      • Muscular pump

        • Heart

  • Open Circulatory System

    • Taxonomy

      • Invertebrates

        • Insects

        • Arthropods

        • Mollusks

    • Structure

      • No separation between blood and interstitial fluid

        • Hemolymph

  • Closed Circulatory System

    • Taxonomy

      • Invertebrates

        • Earthworms

        • Squid

        • Octopuses

      • Vertebrates

    • Structure

      • Blood confined to vessels and separate from interstitial fluid

        • 1 or more hearts

        • Large vessels to smaller vessels

        • Material diffuses between blood vessels and interstitial fluid

  • Adaptations in a Closed System

    • Number of heart chambers differs

  • Evolution of a 4-chambered Heart

    • Selective forces

      • Increased body size

        • Protection from predation

        • Bigger body = bigger stomach for herbivores

      • Endothermy

        • Can colonize more habitats

      • Flight

        • Decrease population and increase prey capture

    • Effect of higher metabolic rate

      • Greater need for energy, fuels, oxygen, and waste removal

        • Endothermic animals need 10x more energy

        • Need to deliver 10x fuel and oxygen to cells

  • Vertebrate Cardiovascular System

    • Chambered heart

      • Atrium

        • Receive blood

      • Ventricle

        • Pump blood out

      • Blood vessels

        • Arteries

          • Carry blood away from heart

        • Veins

          • Return blood to heart

        • Cappilarries

          • Thin wall

          • Exchange/diffusion

Capillary beds = networks of capillaries

  • Arteries

    • Built for high pressure pump

    • Thicker walls

      • Provide strength for high pressure pumping of blood

    • Narrow diameter

    • Elasticity

      • Elastic recoil helps maintain blood pressure even when the heart relaxes

  • Veins

    • Built for low pressure flow

    • Thinner-walled

    • Wider diameter

      • Blood travels back to the heart at a low velocity and pressure

      • Lower pressure

        • Distant from heart

        • Blood must flow by skeletal muscle contractions when we move

          • Squeeze blood through veins

      • Valves

        • In larger veins, there are one-way valves that allow blood to flow only toward the heart

  • Capillaries

    • Built for exchange

    • Very thin walls

      • Lack 2 outer wall layers

      • Only endothelium

        • Enhances exchange across capillaries

      • Diffusion

        • Exchange between blood and cells

  • Lymphatic System

    • Parallel circulatory system

      • Transports white blood cells

        • Defending against infection

      • Collects interstitial fluid and returns blood

        • Maintains volume and protein concentration of blood

        • Drains into circulatory system near the junction of the vena cava and right atrium

  • Heart Valves

    • 4 valves in the heart

      • Flaps of connective tissue

      • Prevent backflow

    • Atrioventricular valve

      • Between atrium and ventricle

      • Keeps blood from flowing back into atria when ventricles contract

    • Semilunar valves

      • Between ventricle and arteries

      • Prevent backflow from arteries into ventricles while they are relaxing

  • Heart Sounds

    • Closing of valves

      • “Lub”

        • Recoil of blood against close atrioventricular valves

      • “Dub”

        • Recoil of blood against the semilunar valves

    • Heart murmur

      • Defect in valves cause hissing sound when a stream of blood squirts backward through the valve

  • Cardiac Cycle

    • 1 complete sequence of pumping

      • Heart contracts and pumps

      • Heart relaxes and chamber fill

      • Contraction phase

        • Systole

        • Ventricles pump blood out

      • Relaxation phase

        • Diastole

        • Atria refill with blood

robot