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Central nervous system fatigue, or central fatigue, is a form of fatigue that is associated with changes in the synaptic concentration of neurotransmitters within the central nervous system (CNS; including the brain and spinal cord) which affects exercise performance and muscle function and cannot be explained by peripheral factors that affect muscle function.
Various cell types play a role in HR, including astrocytes, smooth muscle cells, endothelial cells of blood vessels, and pericytes. These cells control whether the vessels are constricted or dilated, which dictates the amount of oxygen and glucose that is able to reach the neuronal tissue. Brain blood vasculature as a function of blood flow.
Neuroplasticity is the process by which neurons adapt to a disturbance over time, and most often occurs in response to repeated exposure to stimuli. [27] Aerobic exercise increases the production of neurotrophic factors [note 1] (e.g., BDNF, IGF-1, VEGF) which mediate improvements in cognitive functions and various forms of memory by promoting blood vessel formation in the brain, adult ...
Muscle fatigue may be due to precise molecular changes that occur in vivo with sustained exercise. It has been found that the ryanodine receptor present in skeletal muscle undergoes a conformational change during exercise, resulting in "leaky" channels that are deficient in calcium release. These "leaky" channels may be a contributor to muscle ...
Homeostatic capacity refers to the capability of systems to self-stabilize in response to external forces or stressors, or more simply the capability of systems to maintain homeostasis. [1] [2] For living organisms, it is life's foundational trait, consisting of a hierarchy and network of traits endowed by nature and shaped by natural selection.
Short-term synaptic depression can affect many synapses of many different types of neurons. [5] The existence and observations of synaptic fatigue are accepted universally, although the exact mechanisms underlying the phenomenon are not completely understood. It is generally seen in mature cells at high frequencies of stimuli (>1 Hz).
During diving, the hematocrit and hemoglobin are temporarily increased by reflex splenic contraction, which discharges a large additional amount of red blood cells. The brain tissue of diving mammals also contains higher levels of neuroglobin and cytoglobin than terrestrial animals.
Fused tetanus is when there is no relaxation of the muscle fibers between stimuli and it occurs during a high rate of stimulation. [5] A fused tetanic contraction is the strongest single-unit twitch in contraction. [6] When tetanized, the contracting tension in the muscle remains constant in a steady state. This is the maximal possible ...