Circulatory System

1
Circulatory System

• By Trent Lowenstein, Justyn Jordan, Robyn
  Birchall, Jennifer Hanson, Alexa Gil

2
Functions of the Circulatory System

• The human circulatory system consists of the
  heart, a series of blood vessels, and the blood
  that flows through them.

3
The Heart

• The heart is enclosed in a protective sac of
  tissue called the pericardium.
• There are two thin layers of epithelial and
  connective tissue that form a sandwich around a
  thick layer of muscle called the myocardium.

4
Lub Dub Sound

• When the valves between the upper chambers
  (atria) and lower chambers (ventricles) close, a
  "lub" sound is heard.
• When the valves in the pulmonary and aortic
  arteries leaving the heart close, a "dub" sound
  is heard followed by a longer pauseLub-DubLub-D
  ub.

5
Structures of the Heart

• -Superior Vena Cava Large
• Vein that brings oxygen
• poor blood from the upper part
• of the body to the right atrium
• -Pulmonary Veins Brings oxygen- rich blood
• from each of the lungs to the left atrium
• -Pulmonary Valve Prevents blood from the
• flowing back into the right ventricle after it
  has
• entered the pulmonary artery.
• -Tricuspid Valve Prevents blood from flowing
• back into the right atrium after it has entered
• the right ventricle.
• -Inferior Vena Cava Vein that brings oxygen-poor
• blood from the lower part of the body to the
  right
• atrium.
• -Aorta Brings oxygen-rich blood from the left
  ventricle
• to the body
• -Pulmonary arteries Bring oxygen poor blood to
  the
• right or left lung.

6
Arteries, Veins, and Capillaries

• Arteries Large vessels that carry blood from the
  heart to the tissues of the body. Except for the
  pulmonary arteries all arteries carry oxygen rich
  blood to the heart.
• Capillaries The smallest of blood vessels that
  are very narrow that blood cells usually pass
  single file. Bringing nutrients and oxygen to the
  tissues and absorption of carbon dioxide is the
  capillaries contribution to the circulatory
  system
• Veins Bring blood, after passing through
  capillaries, back to the heart.

7
Blood Pressure

• When medical workers measure blood pressure, they
  use a device called a sphygmomanometer. As the
  pressure is released from wearing the cuff, two
  numbers show. The first number is the systolic
  pressure- the force felt in the arteries when the
  ventricles contract. The second number is the
  diastolic pressure- the force of the blood felt
  in the arteries when the ventricles relax.

8
Blood Cells

• White blood cells the army of the circulatory
  system that guard against infection, fight
  parasites, and attack bacteria.
• Blood Clotting blood clotting is made possible
  by plasma proteins and cell fragments called
  platelets.
• Examples
• -Break in capillary wall-blood vessels are
  injured
• clumping of platelets- platelets clump at the
  site and release thromboplastin which converts
  prothrombin into thrombin
• clot forms- thrombin converts fibrinogen into
  fibrin, which causes a clot that prevents further
  loss of blood.