Ch 4 Test Yourself Flashcards
List three fluid compartments in the body
Intracellular, interstitial, intravascular
What is an electrolyte?
A charged particle (an anion or a cation) capable of conducting an electric current in solution
Give specific examples of both cation and anions
Cations:
* Potassium (K+)
* Magnesium (Mg2+)
* Calcium (Ca2+)
* Sodium (Na+)
Anions:
* Sulfate (SO42−)
* Hydrogen phosphate (HPO4 2−)
* Chloride (Cl−)
* Bicarbonate (HCO3−)
Which electrolytes are normally more concentrated outside the cell and which ones are more concentrated inside the cell?
Potassium is more concentrated inside the cell, sodium is more concentrated outside the cell
What is the relationship between solutes and osmolality?
Osmolality is a measurement of the concentration of solute in fluid; as the concentration of solute increases, osmolality also increases
Give specific examples of solutes in the body
Soluble proteins, phospholipids, cholesterol, triglycerides, sulfate, hydrogen phosphate, chloride, bicarbonate, magnesium, calcium, potassium, sodium
Why do changes in osmolality cause fluid to move from one compartment to another?
Water moves freely between fluid compartments based on changes in osmolality; fluid moves toward the compartment with the highest concentration of solutes
Give two examples of conditions that result from fluid shifts
Pulmonary edema, cutaneous edema
How do changes in the osmolality of body fluids affect an animal’s desire to drink?
An increase in osmolality stimulates the desire to drink and the release of antidiuretic hormone (ADH)
What is diffusion? Is it an active or a passive membrane process?
Diffusion is the passive movement of solute down a concentration gradient
What molecules are more likely to diffuse into a cell? What three principles are involved?
Molecules: Very small molecules (e.g., water), lipid-soluble molecules (e.g., alcohol, steroids), dissolved gases (e.g., O2, CO2)
Principles:
* Molecular size
* Lipid solubility
* Molecular charge
How is facilitated diffusion different from simple diffusion?
Facilitated diffusion requires the assistance of an integral protein or carrier protein; the number of available carrier proteins limits the rate of facilitated diffusion
What effect does a hypotonic solution have on a cell?
Water flows into the cell causing it to swell and possibly burst
What is the relationship between hydrostatic pressure and filtration?
Filtration is based on a pressure gradient; liquids are pushed through a membrane if the pressure on one side is greater than the other
What is another name for hydrostatic pressure in the body?
Blood pressure
What defines a passive membrane process?
A passive membrane process is one that does not require energy (ATP)
When is a membrane process considered active?
When the process requires energy
How do electrolytes enter the cell?
Via active transport
What is the difference between a symport and an antiport system?
Symport moves substances in the same direction; antiport moves substances in opposite directions
Describe how sodium and potassium enter and exit the cell
Potassium tends to diffuse out, sodium diffuses in; the cell must actively pump potassium in and sodium out
Describe the three types of endocytosis
Phagocytosis (solid material engulfing), pinocytosis (liquid engulfing), receptor-mediated endocytosis (specific ligands engulfing)
What is the difference between excretion and secretion?
Excretion is waste removal; secretion is movement of manufactured molecules; both are examples of exocytosis
What are the principal ions involved in maintaining a cell’s resting membrane potential?
Sodium and potassium
Is there normally a higher concentration of sodium inside or outside the cell?
Outside the cell
