BASIC MEDICAL SCIENCE: a somewhat random assortment

 

CURRENT CONTENTS:
Autophagia
Ejection Fraction (left ventricular)

Gamma Rays

Haversian canals
Homeostasis

Horseshoe kidney (congenital malformation)

Authors' Note:  In disease states, including those producing congestive heart failure, the ejection fraction of the left ventricle, a measure indicating the strength of contraction, provides important information concerning prognosis (potential outcome) and the need for treatment. 

   The ejection fraction can be measured by echocardiography, magnetic resonance imaging, or several different nuclear (radio-isotope) techniques. These techniques measure the volume of the ventricle at the end of diastolic (relaxation) and systolic (contraction) phases of the cardiac cycle. Despite the name, the change during systole is generally given in medical jargon as the percent relative change, rather than as a true fraction; e.g. 60% is good, 30% is bad.

Authors' Note: 

Authors' Note: For physiologists and physicians, the understanding of homeostatic mechanisms such as feedback loops, and how they get overwhelmed in disease, is critical. An example discussed here previously is regulation of thyroid hormone levels. Knowledge in this area has also expanded into the field of IT.

Authors' Note: Horseshoe kidney is a relatively common congenital malformation, occurring in 1/500 individuals. Also known as renal fusion, it results from the merging of two fetal kidneys in the pelvis during the stage of embryonic organ development and consequently failing to undertake their normal upward migration. Fortunately, health consequences are usually mild, if any; occasionally, one of the ureters becomes obstructed. The abnormal structure is often discovered incidentally during procedures, e.g. CT scanning or ultrasound, targeted at pelvic discomfort or unrelated symptoms (and of course, no normal kidneys are seen in their usual position).