Homeostasis Flashcards
is the process by which living organisms maintain a stable internal environment despite external changes. It involves the regulation of various physiological parameters to keep them within a narrow range conducive to life.
Homeostasis
Most organisms maintain a core body temperature (e.g., humans ~37°C) through what?
Thermoregulation
What are the mechanisms of thermoregulation
Mechanisms include sweating, shivering, and altering blood flow.
The regulation of water and solute concentrations. Kidneys play a crucial role in maintaining water balance and electrolyte concentrations.
Osmoregulation
refers to the physiological processes that maintain a fixed concentration of cell membrane-impermeable molecules and ions in the fluid that surrounds cells.
Osmoregulation
Regulated by insulin and glucagon. After a meal, insulin is released to lower blood sugar, while glucagon raises it during fasting.
Blood Glucose Levels
A change in a physiological variable triggers a response that counteracts the initial change. For example, if body temperature rises, mechanisms to cool the body are activated (sweating, vasodilation).
Negative Feedback
Most homeostatic processes are regulated by feedback systems, primarily negative feedback.
Feedback systems
Less common; enhances a change in a variable (e.g., during childbirth, the release of oxytocin increases contractions until delivery).
Positive feedbacks
Detect changes in the internal environment (e.g., thermoreceptors for temperature).
Sensors
generally a region of the brain called the hypothalamus, signals an effector (e.g. muscles or an organ ) to respond to the stimuli. Positive feedback enhances or accelerates output created by an activated stimulus.
Integrating Center
Organs or cells that enact the response to restore balance (e.g., sweat glands, muscles).
Effectors
Essential for the survival of organisms; failure to maintain homeostasis can lead to diseases or death.
Importance of Homeostasis
