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Definition
| An alternate theory explaining fatigue that proposes that processes occur in the brain that regulate power output by the muscles to maintain homeostasis and prevent unsafe levels of exertion that could lead to tissue damage or cause catastrophic events. By decreasing the recruitment of muscle fibers, the central governor thus limits exercise. |
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Term
| EAMCs (Exercise-associated muscle cramps) |
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Definition
| Defined as painful, spasmodic, involuntary contractions of skeletal muscles that occur during or right after exercise. Two theories for why these cramps occur are that either neuromuscular control becomes altered, causing the muscle spindle to be excited while the Golgi tendon is inhibited, creating abnormal a-motor neuron activity and reduced inhibitory feedback localized in the overworked muscle, and heat cramps, which involves electrolyte deficits in athletes who have been sweating excessively when large muscle groups "lock up". |
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Term
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Definition
| Hormones that have chemical structures similar to cholesterol since most are derived from it. They are soluble in lipids so they easily diffuse through cell membranes. They include testosterone, estrogen, progesterone, cortisol and aldosterone. |
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Term
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Definition
| Hormones that are not lipid soluble, so they can't easily cross cell membranes. They're divided into two groups, protein (peptide) hormones and amino acid-derived hormones. Amino acid-derived hormones are the two hormones developed by the thyroid gland and the adrenal medulla gland, whereas all other non-steroid hormones are protein or peptide hormones. |
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Term
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Definition
| The process of a steroid hormone binding to its specific receptor, at which point the hormone-receptor complex enters the nucleus, binds to part of the cell's DNA, and activates certain genes. This leads to the mRNA synthesizing with the nucleus and entering the cytoplasm, promoting protein synthesis. |
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Term
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Definition
| Catecholamines are the collective name of the epinephrine and norepinephrine hormones released by the adrenal medulla. They function as neurotransmitters in the sympathetic nervous system, however, their effects last longer since they're removed from the blood slowly. Their effects include increased heart rate and force of contraction, increased metabolic rate, increased glycogenolysis in the liver and muscle, (breakdown of glycogen to glucose), increased release of glucose and FFA's into the blood, redistribution of blood to the skeletal muscles, increased blood pressure and increased respiration. |
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Term
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Definition
| Also known as hydrocortisone. It is the major corticosteroid, and is responsible for about 95% of all glucocorticoid activity in the body, including stimulating gluconeogenesis to ensure an adequate fuel supply, increasing mobilization of FFAs, making them more available as an energy source, decreasing glucose utilization, sparing it for the brain, stimulates protein catabolism to release amino acids for use in repair, enzyme synthesis and energy production, acts as an anti-inflammatory agent, depresses immune reactions and increases the vasoconstriction caused by epinephrine. |
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Term
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Definition
| A major hormone released by the pancreas that aids in controlling the plasma glucose concentration of the body. After a meal, when blood glucose is elevated, insulin is released, which then facilitates glucose transport into the cells, especially muscles fibers, promotes glycogenesis and inhibits gluconeogenesis. Its main function is to reduce the amount of glucose circulating in the blood. |
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Term
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Definition
| Secreted by the pancreas when plasma glucose concentration falls below normal levels. Opposing insulin, glucagon promotes increased breakdown of liver glycogen to glucose (glycogenolysis) and increased gluconeogenesis, increasing the plasma glucose levels. |
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