Overload: maintaining homeostasis

The nervous and endocrine systems exert the ultimate control over homeostasis because they coordinate the functions of the body's systems. Regulation of body temperature, blood pressure, pH, and glucose concentration are four examples of how the body maintains homeostasis. The circulatory system is critical to the internal environment in that tissue fluid is nourished and purified by the movement of small molecules across capillary walls. The digestive system contributes nutrients to the blood, while the excretory system removes wastes. The respiratory system takes in oxygen and excretes carbon dioxide. Oxygen is used during cellular respiration and carbon dioxide is a waste product of cellular respiration. The nervous and endocrine systems exert the ultimate control over homeostasis because they coordinate the functions of the body's systems. Regulation of body temperature, blood pressure, pH, and glucose concentration are four examples of how the body maintains homeostasis. The hypothalamus is involved to a degree in each of these regulations. The hypothalamus contains a regulatory center for body temperature but is also involved in regulation of blood pressure and breathing rate through its control over the medulla oblongata. Through the production of hypothalamic-releasing factors and release-inhibiting factors, the hypothalamus directly controls the pituitary gland and indirectly controls the secretions of other glands, such as the thyroid and the adrenal cortex. The body has both short-term and long-term measures to control bodily conditions. In regard to temperature control, the short-term measures include shivering and constriction of arteries to conserve body heat, and dilation of arteries along with sweating to lose body heat. A significant long-term measure to increase body temperature is an increase in thyroxin. Thyroxin raises the metabolic rate. A rapid elevation in blood pressure occurs when the vasomotor center stimulates the constriction of abdominal blood vessels and increases the heartbeat. A longer lasting effect occurs when the kidneys secrete renin leading to a reabsorption of sodium and water. The resulting increase in blood volume increases blood pressure. The pH of the body is immediately regulated by chemical buffers, while the excretion of carbon dioxide must wait until blood moves through the lungs. The kidneys are also involved in regulating blood pH, but the effect may not noticed for up to twenty hours. The blood glucose level is usually regulated by insulin and glucagon. But other hormones can also have an effect since thyroxin and glucocorticoids promote gluconeogenesis. A feedback mechanism is often involved in maintaining homeostasis. The temperature-regulating center is activated when the body temperature rises above or falls below a certain level. Once the temperature is within a normal range, the center stops sending out stimulatory nerve impulses. The vasomotor center promotes a rise in blood pressure, but once this has been attained the center is no longer active. If the pH becomes too acidic, the chemoreceptors in the aortic and carotid arteries signal the respiratory center and the breathing rate increases. Once the pH is within a normal range, these bodies no longer signal the respiratory center and breathing rate returns to normal. When glucose concentration is high, insulin is secreted; but once the glucose level falls, insulin is not secreted. These examples make it clear that feedback is a self-regulating mechanism.

How do you maintain homeostasis?Ho

Overload: maintaining homeostasis:- Maintaining homeostasis in the face of chronic stress means increasing the synthesis of specific proteins (mitochondrial enzymes, for example) that enable the cell to respond to future demands with less disruption. The optimal training program would be one that maximally stimulated these positive adaptations while minimising the cellular and systemic stress thrown at the body in order to trigger the changes. Very hard training does damage and sometimes threatens our health by transiently lowering our resistance to infection, not to mention the fact that it can stress our time schedules and relationships.

Explain homeostasis?