Getting to the Heart of the Matter

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Getting to the Heart of the Matter

• The Circulatory System

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The Circulatory System

• Components
• Heart cardiac muscle, involuntary
• blood vessels lined w/smooth muscles
• Blood is a tissue
• AKA (also known as) - Cardiovascular System
• Cardio means heart
• Vascular means blood vessels

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• The blood vessels of the circulatory system reach
  throughout the entire body
• Blood flows through these vessels to every organ
  in the body
• Capillaries reach every cell of the body

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Functions

• Carries needed materials to the cells
• Oxygen from the lungs
• Glucose for energy
• Carries waste products away from the cells
• Carbon dioxide (CO2)
• Other wastes
• Carries cells that fight disease throughout the
  body (white blood cells)

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The Heart

• The heart is made up of four chambers (sections)
• Split into left and right side by a muscular wall
  (septum)
• The heart works with the lungs to provide oxygen
  to the body

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Parts of the Heart

• Atrium the two upper chambers of the heart
• Receive blood coming into the heart
• Ventricles the two lower chambers of the heart
• Pump blood out of the heart
• Valve a flap of tissue that prevents blood from
  flowing backward
• Located between each chamber and in the veins

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Label the heart on your notes
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How the Heart Works

• The heart muscle relaxes and the atrium fill with
  blood
• The atrium contract, pushing blood into the
  ventricles
• The ventricles contract to pump the blood out of
  the heart and into the arteries

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The Heart Beat

• The sound that your heart makes is the valves
  between the chambers opening and closing
• lub-dub, lub-dub

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Your heart does not work alone

• Your brain tracks the conditions around
  youclimate, stress, and your level of physical
  activityand adjusts your cardiovascular system
  to meet those needs

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Regulation of Heartbeat

• The pacemaker regulates the heart beat.
• A group of cells located in the right atrium
• Sends signals that make the heart contract
• Constantly receives internal stimuli about the
  bodys oxygen needs

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Two Loops

• In one loop
• blood travels from the heart to the lungs and
  back to the heart.
• In the second loop
• blood travels from the heart to the body and
  back to the heart.

http//www.mikecurtis.org.uk/heart.htm
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First Loop to the lungs and back

• Blood from the body enters the right atrium
• Through a valve to the right ventricle
• Out of the right ventricle into the pulmonary
  artery ? to the lungs where the blood releases
  waste gases and picks up oxygen
• L R atria pump together

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Do right and left seem backward?

• That's because you're looking at an illustration
  of somebody else's heart
• To think about how your own heart works, imagine
  wearing the picture on your chest

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Second Loop-to the body and back

• The newly oxygen-rich blood (shown in red)
  returns to the heart and enters the left atrium
• Through a valve into the left ventricle
• The left ventricle contracts, pushing the blood
  into the aorta ? eventually to all parts of the
  body
• L R ventricles pump together

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http//www.pbs.org/wgbh/nova/heart/heartmap.html
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Three kinds of Blood Vessels

• Arteries blood vessels that carry blood away
  from the heart
• Veins blood vessels that carry blood back to
  the heart
• Capillaries tiny blood vessels capable of
  exchange substances between the blood and body
  cells

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Three kinds of Blood Vessels
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Study Your Notes!!

• You will take a quiz over these notes tomorrow