Transport Systems in Animals: Circulatory Systems

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Transport Systems in Animals Circulatory Systems
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What is the role of the circulatory system?

• maintain internal homeostasis
• deliver oxygen, food and other nutrients
  throughout the body
• remove CO2 and other metabolic wastes
• maintain cells in a fluid environment that allows
  exchange of these many materials

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To do all of this, the circulatory system must
come into contact with most tissues in the human
body.
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Which of the organisms below have transport
systems? Which do not?
How can the paramecium and hydra thrive with no
circulatory system?
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Open vs. Closed Systems
Which system seems more efficient? What are your
reasons?
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There are several types of transport systems in
animals

• Animals that have true circulatory systems
  contain specialized circulatory fluid- Blood
• Open Circulatory System
• Body fluid is pumped through open ended vessels
  and bathes organs.
• Occurs in insects, crabs, and other animals that
  carry their skeleton outside of their body
• Blood is circulated by the heart

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• A closed circulatory system
• blood is confined in vessels.
• Major vessels branch into smaller vessels that
  carry blood to organs.
• Blood is pumped through the body by the heart.
• Blood flow is faster than in an open system
• Common in animals that move quickly and transport
  oxygen long distances.

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Evolution of Vertebrate Circulatory Systems

• Which type of circulatory system would be
  advantageous to life on land?
• More efficient circulatory systems- the closed
  circulatory system.

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Several types of blood vessels exist in the
circulatory systems of vertebrates.

• What are the three types of blood vessels?
• Arteries, capillaries, veins

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Blood Vessels

• Blood travels through three types of vessels
• What are some differences you notice between
  these vessels?
• 1. Arteries 2. Capillaries 3. Veins

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What is the purpose of the valves found in veins?
Keep blood flowing toward the heart.
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Why must the capillary walls be so thin?
So materials can diffuse through the wall for
exchange.
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What are some differences between the wall of the
artery and the vein?
Artery walls are thicker to withstand the
increased pressure.
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Blood Vessels - Summary

• Arteries carry blood away from the heart,
  thickest walls
• Veins carry blood toward the heart, thinner
  walls, one-way valves
• Capillaries extremely thin walls, sites of
  exchange in lungs and body cells

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How do these three different circulatory systems
compare?
What are systemic capillaries? Capillaries that
are located throughout the body
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Circulation in Fish
How many chambers does the heart have? -2
chambered heart How many loops does this
circulatory system have? 1 Blood is oxygenated in
gills and travels to the body Heart? gills?
systemic? heart
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Circulation in amphibians and reptiles
How many chambers does the reptilian heart
have? -3 chambered heart How many loops does this
circulatory system have? 2 (double loop
circulatory system) Trace the blood flow through
the body Heart? lungs? heart? systemic Where is
the inefficiency in the amphibian 3-chambered
system?
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The Heart and Blood Flow in Mammals

• How many chambers does the mammalian heart have?
• -4 chambered heart
• How many loops does this circulatory system have?
• 2 (double loop circulatory system)
• Trace the blood flow through the body
• Heart? lungs? heart? systemic circuit
• How is this heart more efficient than the
  reptilian heart?

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Heart Animation
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The Mammalian Heart
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The Cardiac Cycle

• The heart is composed of cardiac muscle and each
  beat is a muscle contraction and relaxation
• Contraction Systolic Pressure
• Relaxation Diastolic pressure
• How is blood pressure written?
• Systolic / diastolic

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Blood Pressure

• What is blood pressure?
• The force that blood exerts against vessel walls
• Is BP is greater in arteries or veins?
• In arteries
• Find your pulse- what are you feeling here?
• Pulse is measure of BP
• Which would have a higher blood pressure,
  constricted blood or dilated vessels?
• Constricted vessels
• Does the BP have an effect on veins?
• No- the pressure is lost in the capillaries
• How, then does blood move in veins?

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• What is average blood pressure?
• 120/80 (mm Hg) of pressure on artery walls.
• Which part of the heart contracts first?
• The atria contract first, followed immediately by
  the ventricles.
• Blood Pressure animation
• Cardiac Cycle Exercises

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• Cardiac Output (CO)
• Volume of blood pumped/ minute
• Stroke Volume (SV)
• Amount of blood pumped by the left ventricle each
  time it contracts (about 75 mL per beat for the
  average person)
• 75 X 70 5 250 mL/min.
• CO is affected by heart rate and SV
• Myogenic heart can regulate its own rhythm
• SA node is the pacemaker of the heart

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How does the heart beat?

• Can you control the beating of your own heart?
• No- the heart muscles contract on their own.
• The heart has a pacemaker, or SA node, that
  maintains the hearts rhythm.
• Heart beat animation

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The pacemaker sets the tempo of the heartbeat.
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What is blood composed of?

• Plasma
• makes up 55 of your total blood volume
• 90 water
• 10 dissolved fats, salts, sugars and proteins.
• Plasma carries nutrients, wastes and important
  proteins like antibodies and clotting factors.
• Erythrocytes (RBCs)
• contain hemoglobin and carry oxygen
• Leukocytes (WBCs) fight disease

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Blood Composition continued...
Diagramatic View
Real Blood Cells
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RBC formation animation
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Blood clotting animation
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Homeostasis

• What is homeostasis?
• The ability of an organism to maintain a stable
  internal environment
• How does this happen?
• the organisms internal environment responds and
  adjusts to changes in the external environment.
• The maintenance of a steady state
• What are some examples of homeostasis in our
  bodies?
• internal temperature, O2 conc., blood glucose