Physiology Part 1 Flashcards
Define homeostasis?
Maintenance of steady states within our bodies by coordinated physiological mechanisms.
What are some components of homeostasis?
Concentration of water and electrolytes within and outside the cells
Pressures and volumes
pH
Body Temperature
Concentration of nutrients e.g. glucose
Concentration of O2 and CO2
concentration of waste products e.g. urea
Where does much of the physiological control occur?
At the level of the cell membrane
What is central to the functionality of the nerve and muscle cells?
Change in membrane potential
What is important for the maintenance of homeostasis?
Physiological control systems
What must a control system be able to do?
Sense deviations
Integrate this information
Make appropriate adjustments to restore a controlled variable to its desired value
What are the two classes of physiological control systems?
Intrinsic controls
Extrinsic controls
Where are intrinsic controls located?
Inherent in an organ
Where are extrinsic controls located?
Outside an organ
By nervous and endocrine systems
What is feedforward?
Responses made in anticipation of a change
What is feedback?
Responses made after a change has been detected
What are the types of feedback systems?
Positive feedback systems
Negative feedback systems
Which feedback system occurs most often?
Negative feedback
What does positive feedback do?
Amplify an initial change
What is the primary type of homeostatic control system?
Negative feedback
