Chapter 1 Flashcards
What is the total amount of fluid or water called?
Total Body Water
What percentage accounts for 50%-70% of body weight
Total Body Water
Total Body water is a higher percentage of body weight when body fat is low and a lower percentage when body fat is high. T/F
True
What are the two major body fluid compartments?
ICF (Intracellular fluid) and ECF (extracellular fluid)
What is contained within the cell and is two-thirds of total body water?
ICF
What is outside of the cell and is one-third of total body water?
ECF
What two compartments is ECF further divided into?
Plasma and Interstitial fluid
What is plasma?
The fluid circulating in the blood vessels and is smaller of the two ECF sub-compartments.
What is interstitial fluid?
The fluid that actually bathes the cells and is the larger of the two sub-compartments.
What fluids are separated by the capillary wall?
Plasma and interstitial fluid.
What is an ultra filtrate of plasma, which is formed by filtration processes across the capillary wall?
Interstitial fluid
T/F The capillary wall is virtually impermeable to large molecules such as plasma proteins, interstitial fluid contains little, if any, protein.
True
T/F The composition of the body fluids is not uniform.
True
Amounts of solute are expressed in?
Moles, equivalents, or osmoles.
Concentrations of solutes are expressed in?
Moles per liter.
An equivalent is used to describe?
The amount of charged (ionized) solute is the number of moles of the solute multiplies by its valence.
One osmole is?
the number of particles into which a solute dissociates in solution.
Osmolarity is?
the concentration of particles in solution expressed as osmoles per liter.
T/F If a solute does not dissociate in solution, then its osmolarity is equal to its molarity.
True
T/F If a solute dissociates into more than one particle in solution then its osmolarity equals the molarity multiplied by the number of particles in solution.
True
pH is?
A logarithmic term that is used to express hydrogen (H+) concentration.
The major cation in_____ is sodium (Na+), and the balancing anions are chloride (Cl-) and bicarbonate (HCO3-)
ECF
The major cations in_____is Potassium (K+) and magnesium (Mg2+) and the balancing anions are proteins and organic phosphates.
ICF
T/F ICF is more acidic (has a lower pH) than ECF.
True
T/F Substances found in high concentration in ECF are found in low concentration in ICF, and vice versa.
True
T/F The total solute concentration (osmolarity) is the same in ICF and ECF.
True; this equality is achieved because water flows freely across cell membranes. Any transient differences in osmolarity that occur between ICF and ECG are quickly dissipated by water movement into or out of cells to reestablish the equality.
T/F The differences in solute concentration across cell membranes are created and maintained by energy consuming transport mechanisms in the cell membranes/
True
T/F Is is critically important that cell membranes are NOT freely permeable to all substances but, rather, have selective permeabilities that maintain the concentration gradients established by energy- consuming transport processes.
True
What is the most significant difference in composition between interstitial fluid and plasma?
Presence of proteins.
T/F Plasma proteins do not readily cross capillary walls because of their large molecular size and therefore are excluded from interstitial fluid.
True
What is Gibbs-Donnan equilibrium?
The plasma proteins are negatively charged, and this negative charge causes a redistribution of small, permeant cations and anions across the capillary wall.
The Gibbs- Donnan Equilibrium can be explained as?
The plasma compartment contains the impermeant, negatively charged proteins. Because of the requirement for electronegativity, the plasma compartment must have a slightly lower concentration of small anions (e.g. Cl-) and a slightly higher concentration of small cations (e.g. Na+, K+) than that of interstitial fluid.
The small concentration difference for permeant ions is expressed in what ratio?
The Gibbs- Donnan ratio which gives the plasma concentration relative to the interstitial fluid concentration for anions and interstitial fluid relative to plasma for cations.
What are cell membranes primarily composed of?
Lipids and proteins
What does the lipid component (in cell membranes) consist of?
Phospholipids, cholesterol, and glycolipids
What is the lipid component (in cell membranes) responsible for?
Responsible for the high permeability of cell membranes to lipid-soluble substances such as carbon dioxide, oxygen, fatty acids, and steroid hormones. It is also responsible for the low permeability of cell membranes to water- soluble substances such as ions, glucose, and amino acids.
What does the protein component of the cell membrane consist of?
Transporters, enzymes, hormone receptors, cell-surface antigens, and ion and water channels.
What do Phospholipids consist of?
Phosphorylated glycerol backbone (“head”) and two fatty acid (“tails”).
The glycerol backbone of the phospholipid is_______.
Hydrophilic (water soluble)
The fatty acid tails of the phospholipid is______.
Hydrophobic (water insoluble)
The phospholipid molecules have both hydrophilic and hydrophobic properties so they are called?
Amphipathic
In cell membranes, phospholipids orient so that the lipid soluble fatty acid tails face each other and the water- soluble glycerol heads point away from each other, dissolving in the aqueous solutions fo the ICF or ECF…which creates a______.
Lipid Bilayer.