Biomed mod.16 obj.1-6

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Biomed mod.16 obj.1-6
2013-03-11 16:34:23
Biomed mod 16 obj

Biomed mod.16 obj.1-6
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  1. The _____ is a strong, muscular _____ just a little over the size of a _____.
    heart, pump, fist
  2. True or false
    The heart pumps about 3,600 gallons of blood through the body in one day, and beats 100,000 times.
  3. What is the position of the heart?
    • The heart is close to the midline
    •   -the c enter is slightly to the left of the midline
    •   -About the same level as the nipples
    • About the size and shape of a closed fist
    • The pointed apex of the heart is inferior and rests on the diaphragm.
    • The base of he heart is superior to the apex
  4. Position of the the heart:
    The mediastinum
    • the heart lies in a cavity called the mediastinum 
    • This consists of:
    •   -The thoracic cavity minus the pleural cavity (lungs and associated structures)
    •   -esophagus
    •   -thymus
    •   -great vessels of the heart
    •   -the heart
  5. The _______ is a membrane that covers and protects the heart.

    This keeps the heart in place in the mediastinum, but gives it enough freedom to contract and beat.
  6. Transesophageal Echocardiography (TEE)
    • an ultrasound (sound wave picture) of the heart
    • shows both cardiac anatomy and function
    • By placing a transducer in the esophagus, physicians can get a picture of the heart that is unobstructed by tissues that limit conventional echocardiography
  7. What are the layers of the Heart wall?
    • Endocardium
    • Myocardium
    • Epicardium
    • Pericardium
  8. Endocardium
    • The deepest layer of the heart wall
    • consists of a thin layer of simple squamous epithelium (endothelium)over a thin layer of connective tissue
    • This provides a smooth surface for the blood as it glows through the chambers and the valves of the heart.
    • This helps prevent friction that may cause blood clots.
  9. Myocardium
    • The thick middle layer (muscular layer of the heart)
    • Makes up 95% of the heart and is responsible for the pumping action.
  10. Epicardium
    • The thin outermost layer of the heart wall
    • a delicate membrane of epithelial and connective tissue giving the heat a slippery covering
    • This is synonymous with the visceral layer of the pericardial covering
  11. The __________ can develop chronic infections with microorganisms that can lodge on the _____ _____ or the ____ of the heart. This is called endocarditis
    endocardium, heart valves, wall
  12. Risk factors for endocarditis
    • heart defects
    • degeneration of the valves
    • transplanted heart valves
    • Rheumatic fever
  13. True or false
    Dental cleaning can allow a small amount of bacteria to enter the blood stream.

    Patients at risk of endocarditis should receive antibiotics prior to dental work.
  14. Pericardium
    • surrounds and protects the heart
    • consists of the serous pericardium and the and the outer most Fibrous pericardium
    • see slide on p.757
  15. Serous pericardium
    • has two layers
    •   -visceral layer: synonymous with the epicardium
    •   -parietal layer: fused to the fibrous pericardium
    • Pericardial fluid fills the cavity between the visceral and parietal layers
  16. fibrous pericardium
    a tough dense connective tissue that precvents the heart from over expanding and anchors to the mediastinum
  17. Pericardial effusion
    • and accumulation of excess fluid in the paricardial cavity 
    • this may occur due to infection, trauma, or myocardial infraction. 
    • The fluid puts pressure on the heart that may become great enough to prevent the it from pumping.
    • This is called cardiac tamponade, and is life threatening.
  18. Histologic features of Cardiac muscle tissue
    • striated like skeletal muscle
    • Unlike skeletal muscle cardiac fibers are shorter, branch, and have on central nucleus
    • contain interculated discs for structural strength
    • Gap junctions to synchronize muscle cell contraction
    • plentiful mitochondria for energy:take up about 25%of the space in the cytosol compared to 2% in skeletal muscle.
  19. What are the four chambers of the heart?
    • Atria: superior protion of the heart, holding chambers for blood
    •   -right atrium
    •   -Left atrium
    • Ventricles: inferior portion, pumps blood to lungs and body
    •   -Right ventricle
    •   -Left ventricle
  20. Right atrium
    This receives deoxygenated blood from the body
  21. Left Atrium
    receives oxygenated blood from the lungs
  22. Right ventricle
    • receives blood from the right atrium
    • it pumps deoxygenated blood out to the lungs
  23. Left Ventricle
    • receives oxygenated blood from the left atrium 
    • it pumps oxygenated blood out to the body.
  24. What are the four valves of the heart?
    • Right atrioventricular valve (AV) tricuspid valve
    •   -right atrium --> right ventricle
    • pulmonary semilunar valve
    •   -regulates blood flow: right ventricle --> pulmonary trunk
    • Left atrioventricular valve (AV) mitral valve (bicuspid valve)
    •   -left atrium -->left ventricle
    • aortic semilunar valve
    •   -regulates blood flow: left ventricle-->aorta
  25. Atrioventricular valves (AV)
    • control the flow of blood between the atria and the ventricles.
    • these include:
    •   -Right atrioventricular or tricuspid valve
    •   -Left atrioventricular, bicuspid, or mital vlave
  26. Semilunar (outflow) valves
    • control the flow of blood leaving the heart from the ventricles.
    • these include:
    •   -Pulmonary semilunar valve
    •   -Aortic semilunar valve
  27. The valves of the heart operate _______.  When enough pressure builds up behind a _____, it forces the valve open.
    pressure, valve

    Valves prevent the backflow of blood.  The are anchored in place by chordae teninae: chordlike tendons that are anchored to papillary muscles.
  28. Functions of the Chambers:
    Ventricles are pumping chambers
    • right ventricle pumps short distance and against low pressure to the lungs
    • Left ventricle pumps long distance and against large pressure to body
    • Therefore, left ventricle muscle wall very thick compared to right.
  29. Function of Valves
    • Valves do not actively open; ratter they are pushed open by increased pressure 
    • chordae tendinae help keep valves in place
    • Valves mainly act as "backflow preventers"