1. Intro to body function Flashcards
How do animals interact w the environment? (DAE)
- Detect and respond to environmental change
- Absorb nutrients and oxygen from the environment
- Excrete carbon dioxide and other wastes into the environment
How do animals regulate internal processes? (DM)
- Distribution of nutrients and oxygen to cells
- Monitoring and regulation of internal fluids.
All processes are governed by _______and ________laws
chemical; physical
What are three human specializations in body function?
thermoregulation, endothermy, homeostasis
Maintenance of the temperature, volume, and composition of body fluids
homeostasis
All internal body fluid. What percentage of the body weight does this make up? Abbreviation?
Total body H2O; 60%; TBW
fluid inside the cells. What part of the TBW does this make up? Abbreviation?
intracellular fluid; 2/3 of TBW; ICF
All fluid outside the cells; plasma + ISF; What part of the TBW does this make up? Abbreviation?
Extracellular fluid; 1/3 of TBW; ECF
ECF within the cardiovascular system; fluid portion of blood
plasma
what is plasma made up of?
mostly H2O (93%) + plasma proteins (7%)
what is blood made up of?
plasma (55% of blood vol) + blood cells (45% hematocrit)
the percentage by volume of red cells in your blood
hematocrit
ECF outside the cardiovascular system
Interstitial fluid ISF
What percentages of body weight are the following: TBW, ICF, and ECF?
60-40-20
What percentages of ECF are plasma and ISF?
33%
What percentages of blood are plasma and blood cells?
plasma= 55% blood cells= 45%
What percentages of plasma volume are plasma proteins and plasma water?
plasma proteins = 7% H2O = 93%
A measure of total solute concentration
osmolarity/ osmotic concentration
What units is osmolarity measured in?
osmoles per liter (Osm/L)
one osmole is equal to ___ _______ of solute particles
1 mole
All body fluids have an osmolarity of (include units)
290 mOsm/L
2 solutions w same osmolarity
isosmotic
solutions w higher osmolarity
hyperosmotic
solution w lower osmolarity
hyposmotic
Solutions with the _______ osmolarity can have ________compositions.
same; different
How does the composition of plasma and ISF differ, and why do they differ?
- similar composition, but plasma has plasma proteins and ISF does not.
- Different because capillary wall acts as a barrier to keep plasma proteins from moving to ISF
The composition of ECF and ICF are very different. What produces this difference?
Because of plasma membrane properties, such as
a semipermeable membrane (proteins regulate movement)
regulate H2O movement across membranes; determine a solution’s osmotic pressure
osmotically active solute
The __________of osmotically active solutes can vary.
permeability
drives water movement between two compartments separated by a water-permeable membrane
osmotic pressure
If two solutions have the same osmotic pressure,
there is no osmosis
What happens when two solutions have different osmotic pressures? Why?
water moves into the solution w higher osmotic pressure; solution w higher pressure “pulls” water into it
Osmotic pressure depends on the __________of a solution and on the _________ _________of its osmotically active solutes
osmolarity; relative permeabilities
Two solutions with the same osmolarity do not necessarily have the same ________ __________
osmotic pressure
the ability of a solution to change cell volume. This ability is related to the solution’s osmotic pressure.
tonicity
What happens to cell volume when placed in an isotonic solution?
no change
What happens to cell volume when placed in a hypertonic solution?
cell vol decreases; cell loses water to solution
What happens to cell volume when placed in a hypotonic solution?
cell volume increases; gains water from solution
What happens in ECF and ICF volumes and osmolarities in response to water deprivation or to high sodium chloride intake?
volume decreases, osmolarity increases.
draws water from ICF to ECF until pressure of both compartments is the same.
