Changes and suggestions for Chapter 4 Circulatory System

The following table lists changes in blue and suggestions in green. The location of  each change and suggestion is specified by page number, text column, and paragraph () in the column. The first line of text in a column begins the first paragraph in that column even if the first line begins in the middle of a sentence.

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CHAPTER 4 Circulatory System

 

 

 

 

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Myocardium   The middle layer of the heartCthe myocardiumCis a thick layer that constitutes most of the wall of the heart. The myocardium consists mostly of heart muscle (cardiac muscle), though it also contains fat tissue and collagen fibers. Contraction of the cardiac muscle provides the force that pumps the blood
 

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The reasons for these increases are the same as the reasons for those which lead to an age‑related rise in other diseases: declining resistance to adverse conditions and  slower repair; more time for the development of slowly progressing diseases; and higher chances for exposure to disease‑producing factors plus increasing occasions and durations of exposure to such factors.

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See photos of normal arteries, atherosclerosis, and heart disease at Preserved Specimen Photos under Chapter 4 Circulatory System.  See microscopic views at Microscpoe Slides .
For more Internet images of normal circulatory system structures and of diseases,
search the Images section of http://www.google.com/ for specific items. For diseases, I highly recommend searching WebPath: The Internet Pathology Laboratory , the excellent complete version of which can be purchased on a CD.
 

78 1 3 Smoking   Inhaling tobacco smoke increases blood pressure and adds substances to the blood that seem to promote the formation of plaque. The effect of smoking on arteries is greatly magnified in women who take birth control pills. The combination of smoking and taking birth control pills increases the risk of having a hear18‑fold. The solution is to not smoke.
 
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The endothelium also secretes several signaling materials including nitric oxide (*NO), prostacyclin, endothelin, and angiotensin converting enzyme (ACE). Nitric oxide and prostacyclin promote vasodilation in many arteries. Nitric oxide also limits vessel thickening by inhibiting the growth of smooth muscle, and it inhibits clot formation and plaque formation. Endothelin and ACE promote vasoconstriction. The effects of *NO usually dominate, keeping vessels adequately dilated.
 

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New information about mechanisms in development of atherosclerosis will be added here. Related information about the heart (e.g., mtDNA, changes in subendothelial and interfibrillar mitochondria, altered calcium regulation, etc.) will either be added into the section on the heart or added here with reference to the section on the heart.
 

 

 

 

 

 

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Copyright 2006 - Augustine G. DiGiovanna - All rights reserved.
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