Pathobiology - McCance - Ch. 3
Total Body Water (TBW) - ANS 60% of the total body weight is water .
How do you express the amount of chemicals/electrolytes that are dissolved in body fluids?
- ANS mEq/L - is related to chemical activity
Where is the 2/3 of the body's water located? - ANS In the intracellular fluid (ICF)
Aquaporins - ANS water channel proteins that allow water to pass through the cell
membrane.
Excessive accumulation of fluid in the interstitial spaces. - ANS Edema
What is net filtration and what is the formula? - ANS the movement of fluid back and forth
across the capillary wall. Net hydrostatic pressure - Net oncotic pressure
What are some pathophysiological causes of edema? - ANS Loss or diminished production
of plasma albumin results in decrease in plasma oncotic pressure.
Venous obstruction can cause increase in capillary hydrostatic pressure.
Increased capillary permeability leads to loss of capillary oncotic pressure.
Lymphatic obstruction leads to decreased absorption of interstitial fluid.
What are electrolytes and some of their properties? - ANS Salts that become ionized in
solution, cannot pass through membranes, affect atom concentrations across membranes,
affect charge differences across membranes, can generate a membrane potential.
What are the 3 hormones that effect electrolyte balance? - ANS antidiuretic hormone,
aldosterone, natriuretic hormone
, What element is like a electrolyte, and why? - ANS Hydrogen. Can alter distribution of other
electrolytes. It indirectly changes the resting membrane potential.
There are 2 gradients that effect membrane potential, what are they? - ANS Ion
concentration gradient: is potential energy to transport things and depolarize cell
Charge gradient: affects the RMP
What ions are primary in the ICF? - ANS Cations: potassium (K) and magnesium (Mg)
Anions: phosphate (PO4) and proteins
What ions are primarily in the ECF? - ANS Cations: Sodium (Na)
Anions: Chloride (Cl) and Bicarbonate (HCO3)
What ion accounts for 90% of ions in the ECF - ANS Sodium
What does calcium do if allowed into the cell? - ANS Calcium binds to phosphate and
precipitates therefore MUST stay out of cytosol. In the cell it also binds to enzymes and
proteins and changes their functions.
What are the normal concentrations of K, Na, and Ca in the blood? - ANS K =3.5-4.5 mEq/L
Na = 136-144 mEq/L
Ca = 8.6-10.5mg/dl
What are hypokalemia, hyponatremia, hypocalcemia,? Some causes? - ANS Potassium
levels below 3.5mEq/L - reduced K intake, Increased entry of K in cells, ↑ excretion of K
Sodium levels below 135 mEq/L - caused by diuretics, extrarenal losses (vomiting),
inadequate intake, dilution,
Calcium levels below 8.5 mg/dl - inadequate intestinal absorption, deposition of ionized Ca
into bone, blood admin,
Most common pathophysiological effects of hypokalemia? - ANS Cardiac and
neuromuscular effects. Cardiac irritiablity, dysrhythmias, vomiting, paralytic ileum, thirst,
inablility to concentrate urine. And associated with metabolic alkalosis.
Total Body Water (TBW) - ANS 60% of the total body weight is water .
How do you express the amount of chemicals/electrolytes that are dissolved in body fluids?
- ANS mEq/L - is related to chemical activity
Where is the 2/3 of the body's water located? - ANS In the intracellular fluid (ICF)
Aquaporins - ANS water channel proteins that allow water to pass through the cell
membrane.
Excessive accumulation of fluid in the interstitial spaces. - ANS Edema
What is net filtration and what is the formula? - ANS the movement of fluid back and forth
across the capillary wall. Net hydrostatic pressure - Net oncotic pressure
What are some pathophysiological causes of edema? - ANS Loss or diminished production
of plasma albumin results in decrease in plasma oncotic pressure.
Venous obstruction can cause increase in capillary hydrostatic pressure.
Increased capillary permeability leads to loss of capillary oncotic pressure.
Lymphatic obstruction leads to decreased absorption of interstitial fluid.
What are electrolytes and some of their properties? - ANS Salts that become ionized in
solution, cannot pass through membranes, affect atom concentrations across membranes,
affect charge differences across membranes, can generate a membrane potential.
What are the 3 hormones that effect electrolyte balance? - ANS antidiuretic hormone,
aldosterone, natriuretic hormone
, What element is like a electrolyte, and why? - ANS Hydrogen. Can alter distribution of other
electrolytes. It indirectly changes the resting membrane potential.
There are 2 gradients that effect membrane potential, what are they? - ANS Ion
concentration gradient: is potential energy to transport things and depolarize cell
Charge gradient: affects the RMP
What ions are primary in the ICF? - ANS Cations: potassium (K) and magnesium (Mg)
Anions: phosphate (PO4) and proteins
What ions are primarily in the ECF? - ANS Cations: Sodium (Na)
Anions: Chloride (Cl) and Bicarbonate (HCO3)
What ion accounts for 90% of ions in the ECF - ANS Sodium
What does calcium do if allowed into the cell? - ANS Calcium binds to phosphate and
precipitates therefore MUST stay out of cytosol. In the cell it also binds to enzymes and
proteins and changes their functions.
What are the normal concentrations of K, Na, and Ca in the blood? - ANS K =3.5-4.5 mEq/L
Na = 136-144 mEq/L
Ca = 8.6-10.5mg/dl
What are hypokalemia, hyponatremia, hypocalcemia,? Some causes? - ANS Potassium
levels below 3.5mEq/L - reduced K intake, Increased entry of K in cells, ↑ excretion of K
Sodium levels below 135 mEq/L - caused by diuretics, extrarenal losses (vomiting),
inadequate intake, dilution,
Calcium levels below 8.5 mg/dl - inadequate intestinal absorption, deposition of ionized Ca
into bone, blood admin,
Most common pathophysiological effects of hypokalemia? - ANS Cardiac and
neuromuscular effects. Cardiac irritiablity, dysrhythmias, vomiting, paralytic ileum, thirst,
inablility to concentrate urine. And associated with metabolic alkalosis.
