What are the appropriate levels of "survival needs"?
-Nutrients
-Oxygen
-Water
-Body temperature
-Atmospheric pressure
Homeostasis
-Body's ability to maint. a relatively stable environment.
-Dynamic state of equilibrium-Internal conditions vary, but only within limits.
-Internal cond. are constantly disrupted by internal and external stimuli. So control requires cont. monitoring and regulation of many factors(variable)
Variable
Condition or event that is being monitored.
Receptor
Monitors the variable.
Control center
Analyzes input from receptors and determines appropriate response input and output.
Effector
Responds to output from control center.
Negative Feedback Mechanism
Reverse the change in the variable.
This is the most common.
Positive Feedback Mechanism
Enhance or strengthen the change in the variable.
What two organ sys. are the most imp. in control of homeostasis.
Nervous and Endocrine.
Matter
Anything that has mass or space.
What are the three states of matter?
-Solid
-Gas
-Liquid
What 4 elements form 96% of body mass?
-Carbon
-Oxygen
-Nitrogen
-Hydrogen
What 9 elements form 3.9% of body mass and their symbols?
-Calcium Ca
-
Phosphorus P-Potassium K
-
Sulfur S
-
Sodium N
-
Chlorine Cl
-
Magnesium Mg
-
Iodine I
-
Iron Fe
What are the building blocks of elements?
Atoms. This gives elements their physical and chemical properties.