Question | Answer |
What causes bloating during menstral cycle & edema during pregnancy? | Estrogen causing NaCl reabsorption |
Progesterone has __ affect & promotes __. | diuretic-like - Na+ & water loss. |
Glucocorticoids promote __. | increased glomerular rate & edema. |
K+ excess in ECF decreases membrane __. | potential - causes depolarization & reduced excitability. |
K+ lack in ECF causes __. | membrane hyperpolarization & nonresponsiveness. |
Shifts of H+ into & out of cells induce shifts of __ in the opposite direction to maintain cation balance. | K+ |
ECF potassium levels __ with acidosis. | rise |
ECF potassium levels __ with alkalosis. | fall |
K+ balance is maintained chiefly by __. | renal mechanisms |
__ is never secreted into the filtrate. | Na+ |
Na+ is never secreted into __ but K+ is. | filtrate |
As plasma Na+ levels rise, K+ levels __. | fall proportionately |
__ cells are directly sensitive to K+ content of ECF bathing them. | adrenal cortical cells |
Adrenal cortical cells release __ when K+ increases, thereby K+ controls its own concentrations in ECF by regulation of __ release. | aldosterone - aldosterone |
Lack of ECF potassium causes __. | hyperpolarization of neurons & paralysis. |
Hypocalcemia causes muscle __. | tetany |
Hypercalcemia __ muscle cells & causes __. | inhibits - cardiac arrhythmias |
Bone breaks down into Ca2+ and __. | HPO42- |
PTH enhances CA2+ absorption by __. | intestines, renal tubules |
Why are proteins influenced by H+ concentrations? | Due to their abundant hydrogen bonds |
The lower pH in venous blood is due to? | Acidic metabolites & CO2 which combines to form carbonic acid, H2CO3 |
pH above __ is alkalosis. | 7.45 |
pH below __ is acidosis/acidemia | 7.35 |
Physiological acidosis | pH between 7.35 & 7.0 |
Most H+ originates as __. | metabolic by-products or end products. |
3 major chemical buffer systems of body are? | bicarbonate, phosphate, & protein buffer systems. |
Bicarbonate buffer system | Carbonic acid (H2CO3) & its salt sodium bicarbonate (NaHCO3). |
What is the only important ECF buffer? | Bicarbonate buffer system - carbonic - sodium bicarbonate |
Alkaline reserve | available HCO3- ions |
Carbonic acid comes from? | The CO2 released during cellular respiration. |
Phosphate buffer system | NaH2PO4 => Na2HPO4 - one less hydrogen atom |
Where is phosphate buffer system most effective? | In urine & ICF where phosphate concentrations are usually higher. |
Protein buffer system | Proteins in plasma & cells - exposed organic acid groups (-COOH) release H+ when pH rises & others bind to the H+ ions. |
A single __ molecule can function as an acid or base depending on the pH of environment. | protein - amphoteric molecules |
Give an example of an amphoteric molecule | Hemoglobin - functions as intracellular buffer. Can buffer carbonic acid - amino acid - protein buffer system. |
Which fluid contains most magnesium? | Intracellular fluid (ICF). |
Which fluid contains most calcium? | Plasma & then interstitial fluid |