Fluid and electrolyte balance Exam Test Questions And Answers Verified 100% Correct

Fluid and electrolyte balance Exam Test Questions And Answers Verified 100% Correct Na+ reabsorption from the PCT into the cell occurs via ______________ - ANSWER - Secondary active transport/cotransport Na+ reabsorption from the cell into the ISF occurs via _________________ - ANSWER - Active transport Na+/K+ pump What ion is coupled with Na+ reabsorption? - ANSWER - Cl- Na+ reabsorption is coupled with ______________ secretion - ANSWER - K+ secretion to prevent changes in electrical potential What hormone influences K+ secretion - ANSWER - Aldosterone What stimulates the release of aldosterone? - ANSWER - Hyperkalemia (Increased K+ lvls in blood) or Angiotensin II What does aldosterone cause? - ANSWER - Causes principle cells to insert more Na+/K+ pumps on the basal membrane & more ion channels on the apical surface. Increases Na+ & K+ gradient Increases reabsorption of Na+ & secretion of K+ Increased Na+ reabsorption causes more water to be reabsorbed increasing blood volume which increases BP What type of hormone is aldosterone? - ANSWER - Steroid hormone released by adrenal cortex What are Macula Densa cells function? - ANSWER - They are specialized chemoreceptors sensitive to Na+ in the DCT and send paracrine signals to granular cells stimulating them to secrete Renin into the bloodstream What are granular cells? - ANSWER - Juxtaglomerular cells that are specialized smooth muscle cells that secrete Renin into the bloodstream What stimulates Macula Densa cells to release their paracrine? - ANSWER - Low BP/Na+ in the DCT (Main Stimulus) Can the sympathetic NS cause the granular cells to release Renin? - ANSWER - Yes Explain the renin-angiotensin-aldosterone system - ANSWER - Liver releases Angiotensinogen (Inactive) Juxtaglomerular cells release Renin Renin activates Angiotensinogen -- Angiotensin I Endothelial cells in pulmonary capillaries detect and release ACE (Angiotensin Converting Enzyme) ACE converts Angiotensin I -- Angiotensin II Angiotensin II is a strong vasoconstrictor of arterioles which increases BP causing adrenal cortex to release aldosterone What are ACE inhibitors used to treat? - ANSWER - hypertension What are the 4 mechanisms that increase MAP in response to Anigotensin II? - ANSWER - Vasoconstriction Aldosterone secretion ADH secretion Thirst Stimulation What is ANP released in response to? - ANSWER - Increased plasma volume How does ANP affect GFR? - ANSWER - Increases GFR by constricting the efferent arterioles & dilating the afferent arterioles. What does ANP cause - ANSWER - Increased GFR Decrease of Renin release Decreased Aldosterone release Goal is to lower BP Where does K+ secretion take place? - ANSWER - In the principle cells of the late distal tubule and collecting duct What causes the release of Calcitonin? - ANSWER - Hypercalcemia What does Calcitonin cause? - ANSWER - Inhibition of Ca2+ reabsorption, stimulates osteoblastic activity What hormone is released in response to hypocalcemia? - ANSWER - PTH What does PTH do? - ANSWER - Increases Ca2+ reabsorption, stimulates osteoclastic activity, increased Ca2+ absorption at the GI tract. Why is it important to decrease phosphate reabsorption when Ca2+ lvls are low? - ANSWER - Because phosphates can bind to Ca2+ decreasing the lvls of free Ca2+ in the body which could stimulate bone breakdown What starts the conversion of VD3 to its active form? - ANSWER - Liver converts to 25- OH D3 Kidney converts to calcitriol (active form) What does VD3 stimulate? - ANSWER - The reabsorption of Ca2+ in the kidneys and GI tract What pH is considered Acidemia? - ANSWER - 7.35 What pH is considered alkalemia? - ANSWER - 7.45 What causes Acidosis and Alkalosis? - ANSWER - Acid build up or bicarbonate loss, high protein/fat diet Acid loss or bicarbonate build up, vomiting What Organs are the primary regulators of Acid-Base balance? - ANSWER - Kidney and Lungs What is the normal blood pH range? - ANSWER - 7.35-7.45 What metabolic changes can cause acidosis? - ANSWER - high protein/fat diet Heavy exercise Severe diarrhea What metabolic changes can cause alkalosis? - ANSWER - Excessive vomiting Kidney Failure What are the 3 defense mechanisms to protect against Acid/Base changes? - ANSWER - Buffers Respiratory compensation Renal compensation