INTRO + BODY FLUIDS Flashcards
What is physiology defined as
the study of the normal, functional activities in the healthy, living organism
What are the basic cell functions
obtaining nutrients + oxygen from the environment, performing various rxns to produce energy which is used for other activities, and then releasing CO2 and wastes into the environment
What is the Milieu Interieur and who discovered it
internal environment surrounding individual cells, Claude Bernard
Name the 2 major conclusions Claude Bernard came to about the Milieu Interieur
- the environment surrounding individual cells is very different from the external environment
- the internal environment remains relatively constant when the organism is healthy
What is the consequence of a change in the internal environment of an organism (disruption of homeostasis)
disease
Define homeostasis and who discovered it
a state of dynamic consistency, Walter Cannon
What is the fundamental principle
at all levels of organization, functional activities are directed at maintaining optimal and relatively constant internal conditions
What are the 7 factors that must be homeostatically controlled
- conc. of nutrient molecules
- conc. of O2 and CO2
- conc. of waste
- conc. of electrolytes
- pH
- temperature
- volume and pressure
What are the 4 aspects of body fluids
- volume
- distribution
- characteristics
- functions
What is the most abundant single constituent in the body
water
Body water acts as a medium in which:
solvents are dissolved, metabolic rxns take place
What are the 8 main functions of water
- protection
- moistens tissues
- flushes wastes (lessens burden on kidneys)
- prevents constipation
- regulates body temp
- carries nutrients and O2 to cells
- dissolves solvents
- lubricates joints
What is the main factor that contributes to the amount of body water an individual has
amount of fat (adipose tissue)
Why does water content decrease with age
tissues become drier, muscle is lost and replaced by drier connective tissue, changes in bone density and increase in deposition of fat
When administering medication, when is body water content important?
administering H20 soluble medication
Name the 2 ways that body water remains in a constant steady state
- taken in and exchanged with environment
2. exchanged internally between different compartments
Define obligatory losses
losses that we will always lose no matter how much fluid we take in:
- insensible losses from lungs and skin
- urine and stool
total: about 1.5 L
Define insensible losses
losses that we are not aware of (lungs and skin)
Define facultative losses
losses that vary with intake
-urine
What is lean body mass
body mass minus fat; makes differences in individual’s body water content insignificant
Differences between insensible perspiration and sweating
pure H2O vs electrolyte solution
passive evaporation vs. active secretion
entire skin surface vs. sweat glands
continuous vs activated by heavy weight or temp
Can an individual who lacks sweat glands still have insensible perspiration
yes because it doesn’t occur in the sweat glands
What does passive evaporation depend on
air temp and humidity
What does active secretion depend on
energy
