Introduction to Physiology and Homeostasis Flashcards
What are emergent properties?
Properties of a complex system that cannot be explained by a knowledge of a systems individual components (The brain).
What is the smallest unit of structure capable of carrying out life processes?
The cell.
What are tissues?
Collection of cells carrying out related functions.
What is the difference between function and mechanism approaches?
Function asks why while mechanism asks how.
What is homeostasis?
The ability to maintain a relatively stable internal environment in spite of exposure to external variability.
What is the role of the extracellular fluid and what sort of state does it maintain?
It is a buffer between cells and the external environment. Dynamic steady state (materials constantly moving back and forth).
What is the law of mass balance?
The amount of substance in the body is to remain constant, any gain must be offset by an equal loss.
What is a dynamic steady state?
A stable disequilibrium. The body compartments are not in equilibrium but they remain rather steady in their individual components/
What is reflex control?
Any long distance pathway that uses the nervous, endocrine system or both.
What are the two loops of reflex control?
- Response loop
2. Feedback loop
What does the feedback loop do?
Modulates the response loop and feeds back to ultimately influence the input.
What does it mean to say that reflex control can be antagonistic?
You can have dual control of any system (Example - Heater and air conditioner).
What are the three types of feedback loops?
- Negative feedback
- Positive feedback
- Feedforward control
What is a negative feedback loop?
A pathway in which the response opposes or removes the signal (stabilizes a system). They are homeostatic.
What are positive feedback loops?
They reinforce a stimulus to drive the system away from a normal value. They are not homeostatic.
