Vertebrate Heart

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Vertebrate Heart
2013-02-20 17:54:19
BIO 220 Test Two

Circulatory System
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  1. a.      Every vertebrate heart is made of __ layers
    What are they?
    • three
    • innermost: endocardium
    • myocardium
    • outermost: epicardium
  2.  i.      Innermost: endocardium
    •                                                               i.      Innermost: endocardium
    • 1.      Continuous with the vessels that enter or leave the heart= endothelium (simple squamous)
  3. Myocardium
    • 1.      Thickest layer to the wall of the heart
    • 2.      Cardiac muscle
    • 3.      Responsible for pumping action and contraction of the chambers 
  4. Outermost: epicardium
    • 1.      Connective tissue and simple squamous
    • 2.      Part of mesothelium
    • 3.      Visceral pericardium and epicardium are synonymous terms
  5. Pericardium
    how many layers?
    •                                                               i.      Serous membrane surrounding heart
    •                                                               i.      Two layers
    • 1.      Outer parietal pericardium
    • 2.      Inner visceral pericardium (epicardium)
    • a.      Also the outer layer of the wall of the heart
  6. Function of the Pericardium Function
    •                                                               i.      Function: (like every serous membrane)
    • 1.      Protection, anchoring, reduction of friction as the organ moves in the same
  7. Chambers                                                              
    Every vertebrate heart has at least one __and one __
    • atrium
    • ventricle
  8. Explain atria.
    they receive:

    • a.      Blood enters through atria
    • b.      Veins dump blood into atria
    • c.       Myocardial in atria are much thinner than myocardia of ventricles
  9. Ventricles are __ chambers.

    • a.      Blood leaves through ventricles
    • b.      Arteries take blood away from ventricles
    • c.       Ventricles are thicker in muscle because they have to push it to the body, while the atria just take it to the ventricles
    •                                                                                                                                       i.      Left ventricular walls are thicker walled than right ventricular walls
  10. In three-chambered organisms: 
    if you look at the endothelium of htese chambers, what's wronge?
    they're not always smooth
  11. Endothelium atrial irregularities are called __.
    musculi pectinati

    •  a.      When you look at the chamber, the wall isn’t smooth
    •                                                                                                                                       i.      Looks like teeth of a comb because the arrangement of the myocardium is irregular
    • b.      Due to muscle arrangement
  12. Endothelium ventricular muscular irregularities, are called __.
    • trabeculae carneae
    • a.      Appears to have nooks and crannies
  13. Function of trabeculae carneae in three-chambered heart
    Hold the blood; play a major role in preventing mixing of blood between the two valves (of oxygenated and deoxygenated blood
  14.                                                               i.      Between every ventricle and atrium is an __ valve
  15. Atrioventricular Valve
                                                                  i.      The valve that goes between an atria and a ventricle
  16. Fucntion of AV valve
    1.      Prevents backflow back up into the atrium
  17. AV Valve structure
    •                                                               i.      Has a very elaborate structure
    • 1.      Two or more cusps (flaps)
    • a.      Angled so pointing toward ventricle
    • 2.      Underneath cusps are a series of firbrous cords, called chorda tendinae
    • 3.      Chorda tendinae insert into mounds of muscles that jut into the wall called papillary muscles
    • a.      Anchor chorda tendinae into ventricular wall
    • 4.      These chords and papillary muscles prevent everting
    • a.      Anchorage prevents flaps from turning inside out
  18. Semilunar Valve
                                                                  i.      Cusps that are in the beginning of every artery that leaves the heart
  19. Where are the semilunar valves located?
    1.      Pulmonary artery and the aorta or in terms of the two- chambered artery, the ventral aorta
  20. How many cusps of semilunar valve?
                                                                  i.      Three cusps
  21. Explain semilunar valve contraction and relaxation.
    • 1.      When ventricles contract, the cusps open up to go to the artery
    • 2.      When ventricles relax, the cusps close and you don’t get backflow
  22. True or False: 
    Semilunar valves have anchorage and cusps/

                                                                  i.      Does not have anchorage, just has cusps