Homeostasis (Topic 5) Flashcards
What is intracellular fluid? (2)
Inside the cell (cytosol)
What is extracellular fluid? (2)
Outside of the cell (plasma and interstitial fluid)
What is the difference between plasma and interstitial fluid? (2)
- Plasma is in the blood vessels
- interstitial fluid is outside of the blood vessels
What are some common physiological barriers that must be maintained in within a range? (3)
- temperature
- blood sugar
- pH
- salinity
- blood pressure
What is dynamic constancy? (4)
Physiological variables can change dramatically over a 24-hr. period, but in average, remain stable in the long run
T/F. An organism may be homeostatic for one variable but not for another. (5)
true
T/F. An organism may be homeostatic for one variable but not for another. (5)
true
What is an example of homeostasis penalizing one variable to control another? (5)
sacrificing water balance to regulate temperature
What is heat stroke? (5)
When you run out of water to balance your temperature
What is pathophysiology? (5)
when one or more variables are not in homeostasis
How does the body respond to changes? (6)
- behavioral changes
- physiological regulation
- tolerance
What is tolerance? (6)
Tolerating a variable that is slightly out of range
What is a behavioral change? (6)
A voluntary action
ex: moving into the shade
What is a physiological regulation? (6)
an involuntary action
ex: shivering and sweating
How does shivering help? (6)
muscles contract and use energy, then creates heat
how does body balance sensory input? (7)
Body balances sensory input with functional output
What is the set point? (7)
target value for the variable (average)
What is an error signal? (7)
difference between the true value and the set point
Why is homeostasis not perfect? (7)
The body varies (oscillates) within a range of normal values around a average value.
Practice slide 8 (flow chart of homeostatic control systems)
yay slide 8
What is steady state? (9)
when a variable is not changing (staying in range) but energy is added to keep it steady
Ex: Shivering
What is equilibrium? (9)
no change, no energy required
Ex: Perfect temperature room
What are feedback systems? (10)
Processes that are influenced by the amount of product
What is negative feedback? (10)
change in a variable that results in a response in the opposite direction
ex: increase in blood sugar; response is to lower blood sugar
What is positive feedback? (11)
a change in a variable that results in a response in the same direction
Which is most common, positive or negative feedback? (11)
negative feedback