Homeostasis Flashcards
Explain why it is necessary to control the internal conditions in our body.
Controlling internal conditions is necessary to maintain stable conditions for cellular function and overall health, despite changes in the external environment.
Describe the relationship between the internal environment and the extracellular fluid compartments:
The internal environment includes all the fluids, ions, and nutrients within the body, while the extracellular fluid compartments, such as blood plasma and interstitial fluid, help maintain the internal environment by exchanging materials with cells.
Explain the importance of controlling body temperature in terms of the chemical activity in the body:
Controlling body temperature is crucial because most biochemical reactions are temperature-dependent. Temperature regulation ensures optimal enzyme activity and metabolic function.
Define homeostasis:
Homeostasis is the maintenance of stable internal conditions within an organism despite external changes, achieved through regulatory mechanisms.
Explain the key components of a homeostatic mechanism (control system) and describe the interrelationship of the components:
Controlled variable: The parameter being regulated.
Set point: The desired value or range for the controlled variable.
Sensors (receptors): Detect changes in the controlled variable and send signals to the integrating center.
Afferent pathway: Carries sensory information from the sensors to the integrating center.
Controller (integrating center): Processes sensory information and initiates a response if needed.
Efferent pathway: Carries signals from the integrating center to the effectors.
Effectors: Carry out the response to restore the controlled variable to its set point.
Define the term feedback. Differentiate between positive and negative feedback:
Feedback is the information loop that regulates a physiological process. Negative feedback reduces deviations from the set point, while positive feedback amplifies deviations.
Explain how feedback information is used in homeostatic systems, giving physiological examples of the operation of each type of system:
Negative feedback maintains homeostasis by counteracting changes in the controlled variable. Example: Thermoregulation.
Positive feedback amplifies deviations from the set point, often to bring about a specific physiological event. Example: Childbirth.
What is the primary purpose of homeostasis in living organisms?
The primary purpose of homeostasis is to maintain stable internal conditions, such as temperature, pH, and nutrient levels, despite changes in the external environment.
Explain how negative feedback maintains homeostasis in body temperature regulation:
Negative feedback in body temperature regulation involves sensors detecting deviations from the set point, such as increased temperature. The hypothalamus then triggers responses to counteract the deviation, such as sweating and vasodilation, to lower body temperature back to the set point.
Describe the role of the hypothalamus in homeostatic regulation:
The hypothalamus serves as the control center for homeostatic regulation in the body. It receives input from sensors throughout the body, processes this information, and initiates appropriate responses to maintain internal stability.
How does the body regulate blood glucose levels to maintain homeostasis?
The body regulates blood glucose levels through hormonal mechanisms involving insulin and glucagon. When blood glucose levels are high, insulin is released, promoting glucose uptake by cells and storage. Conversely, when blood glucose levels are low, glucagon is released, stimulating the release of glucose from storage sites to raise blood glucose levels.
Define osmoregulation and provide an example of its importance in maintaining homeostasis:
Osmoregulation is the regulation of water and solute concentrations to maintain internal balance. An example is the kidneys regulating water reabsorption to prevent dehydration or overhydration, ensuring proper cellular function and overall health.
True or False: Homeostasis involves maintaining internal stability despite external changes.
True
True or False: Positive feedback mechanisms are more common in homeostatic regulation than negative feedback mechanisms.
False. (Negative feedback mechanisms are more common.)
True or False: Hormonal regulation plays a significant role in homeostasis.
True
