HES 319 Lecture Notes - Adipose Tissue, Sarcopenia, Endoplasmic Reticulum
Document Summary
Decreased maximal contraction velocity (decreased speed of movement) The ability to produce relatively high muscle force over a period of time (muscle power) also declines with age. This has a negative impact on functional activities. It is relatively well-maintained at first, followed by a steeper decline. Changes with physical activity level vs. intrinsic changes with aging. Aging reduces the number of neurons in the soleus motor nerve of the rat. Aging reduces the number of motor neurons in the ventral horn of the human spinal cord. Aging reduces the number of neurons in the human ventral root. Only partial innervation from adjacent surviving motor neurons occurs. Results: fewer, larger motor units in elderly adults. Number of muscle fibers drops sharply starting in sixth decade of life. Muscle size is reduced substantially with advancing age. Proportion of the number of type 1 and 2 fibers doesn"t change significantly.
