Lecture 6: Aging Flashcards
How does aging influence the heart?
Myocardial ischemia progressively occurs, resulting in reducedmyocytesand an increase in myocyte fibrosis.
Left ventricular hypertrophy (thickening) typically occurs, as does valvular degeneration.Thickening causes a decreased cardiac capacity and less ability for the heart to cope with cardiac stress (e.g. exercise).
There is also a decrease in maximal heart rate (HR).
Reduced ability to increase cardiac output in response to increased tissue demands (e.g. exercise) and an overall increased risk of heart failure.
How does aging influence blood vessels?
Decreasescompliance.The aorta and larger arteries become stiffer due to decreased elasticity.
Decreased ability for vessels to respond homeostatically to changes in blood pressure, meaningorthostatichypotension becomes more common.
Generalizedendothelial dysfunction with subsequent inflammation occurringthroughout the vasculature. Causes an Increase in atherosclerotic plaque formation.
Increase in blood pressure (systolic), though there is often a decrease in diastolic pressure.
How does age influence hematology & immunity
Hematology= the study of blood and blood disorders
Decrease in erythropoiesis and lymphoid cell production. (erythropoiesis= RBC formation). Therefore decreases cell count and hemoglobin concentration.
Decreased activity of the adaptive immune system due to decreased production of lymphocytes (B & T cells), but also due to decreased functionality of these cells, including memory cells.
There is a general increase in pro-inflammatory chemicals with anincrease in inflammatory processessuspected to contribute to the aging process of many (if not all) tissues in the body. However, there is a blunted fever response and WBC numbers do not increase as much in response to infection/trauma. Thus overall there is reduced wound healing and a decreased response to infection, and therefore increased infection susceptibility.
There is a general increase in coagulability activity, which subsequently increases the risk of abnormal blood clot formation anddeep vein thrombosis.
