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 of the Circulatory System

• 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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The 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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Components of Blood
Plasma the liquid part of the blood. Blood
plasma is a pale yellow liquid and contains
dissolved food and other dissolved
substances Red Blood cells contain hemoglobin,
no nucleus, produced in bone marrow White Blood
Cells fight disease Platelets helps clot
blood Hemoglobin found in red blood cells,
protein with iron that binds to oxygen
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Three kinds of Blood Vessels
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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, where exchange
  of substances between the blood and body cells