08 JUL 2016 by ideonexus
Age-Related Decline in Strength as Decline Neurons
“What we have here is (a) failure to communicate,” said the Captain in the 1967 film Cool Hand Luke. This line rings true today as it relates to the failure of physiologists to communicate the mechanisms of muscle strength to the geriatrics community, where the lack of muscle strength observed in older adults holds high clinical significance. Similarly, there is a relative under recognition in the scientific community for the potential role of the brain’s failure to communicate with ske...As the neurons controlling muscle fibers die off, those muscles grow weaker. Possibly exercising muscles might keep signals going to those neurons and keep them alive, staving off age-related cognitive decline.
20 JUN 2013 by ideonexus
Relative Sizes of Structures in the Brain
Linear measure- ments and dimensions generally are given in microns or micrometers (µm) (1 µm equals one- millionth of a meter) or nanometers (nm) (1 nm or millimicron equals one-billionth of a meter). About 240,000 µm equal one inch. As a reference, the following are the dimen- sions of some non-neural structures: human ovum, 100 µm; cross-section of a skeletal muscle fiber, 10-100 µm; erythrocytes, 8–10 µm; bacteria, 0.1–8 µm; and viruses, 0.15–0.5 µm. Cell bodies of neurons...Interesting to see how they compare to the sizes of other small objects.