Homeostasis Flashcards
any self-regulating process by which an organism tends to maintain stability while adjusting to conditions that are best for its survival
Homeostasis
adjusting of physiological system within the body
homeostatic regulation
Three parts/ mechanisms of homeostatic regulation
- Receptor
- Control center
- Effector
receives information that something in the environment is changing
receptor
- aka integration center
- receives and processes information from the receptor
control center
responds to the commands of the control center by either opposing or enhancing the stimulus
effector
Two (2) types of feedback
- Negative feedback
- Positive feedback
- the response will reverse or cause the opposite effect of the original stimulus
- the result of a reaction is reduced to bring the system back to a stable state
negative feedback
- occurs in nature when the product of a reaction leads to an increase in that reaction
- In homeostasis, it moves a system further away from the target of equilibrium
positive feedback
example of negative feedback
regulation of the blood calcium level
example of positive feedback
- Childbirth – stretching of uterine walls cause contractions that further stretch the walls (this continues until birthing occurs)
- Lactation – the child feeding stimulates milk production which causes further feeding (continues until baby stops feeding)
organisms that keep their internal fluids isotonic to their environment, that is, they maintain an internal salinity similar to their ambient conditions
Osmoconformers
organisms that actively regulate their osmotic pressure, independent of the surrounding environment
Osmoregulators
Examples of osmoconformers
- starfish
- crabs
- jellyfish
Example of osmoregulators
freshwater fish
Other homeostatic mechanism
- Osmoregulation
- Thermoregulation
- maintenance of water balance
- organisms regulate osmotic pressure of their body to prevent body fluids from becoming too diluted or too concentrated
osmoregulation