Flashcards
C12: ACIDS AND BASES
Cards in this deck (37)
- 1why is it important for [H+] to be regulated?b/c they affect how enzymes function and that affects the cell
- 2which is more acidic, venous blood or arterial bloodvenous blood
- 3acidosisbody fluids when pH<7.4
- 4alkalosiswhen pH is above 7.4
- 5where does acid come from in the body?in the process of making ATP, CO2 is made as a byproduct and when is combined with water, carbonic anhydrase can turn it into carbonic acid (volatile) which can dissociate into bicarbonate ion and H+...
- 6explain why there is no NET inc in free H+ in the plasmabc the carbonic acid reforms into CO2 which is then removed at the lungs
- 7where does acid come from in the body? (protein way)the breakdown of proteins will produce a number of acids, including sulphuric acid, phosphoric acid, lactic acid and other organic acids
- 8what makes an acid volatileif they can be removed by the lungs -- they exist in a gaseous form
- 9the stomach is a large source of ____hydrochloric acid
- 103 ways acid is made in the body1. CO2
2. breakdown of proteins
3. STOMACH acid - 113 ways the body regulates free H+ concentrations1. buffers
2. the respiratory system
3. the kidney - 12explain how buffers regulate H+buffers in body fluids bind free H+
buffers are the body's first line of defense
buffers do not directly remove H+ from the body nor do they alter pH
they only bind up free H+, stabilizing the pH, until balance can be re restablished by the next two systems - 13respiratory systemcan regulate H+ concentration from volatile acids within seconds to minutes
recall that volatile acids include carbonic acids formed when CO2 combines w water - 14kidneysrespond slowly... over a period of hours or days... have an extremely powerful control over H+ concentrations, particularly from non volatile acids
- 15what is a bufferany molecule that can reversibly bind or release free H+
because buffers bind free H+ and therefore reduce the amt of free H+ in soln, they help stabilize the pH - 162 examples of buffersbicarbonate ions and hemoglobin
- 17the most powerful extracellular buffer isbicarbonate ion HCO3
- 18Hb is a _____ bufferintracellular
- 19Hb can bind to ____ and ____both H+ and CO2 (it only reduces the POTENTIAL acidity of CO2 b/c CO2 has to combin w H2O first to form carbonic acid)
- 20explain how the respiratory system guards against changes in H+by removing CO2
regulation of CO2 lvls in the blood (and thus pH) involves detection of the gas by the central (medulla) and peripheral (carotid sinus + aortic arch) chemoreceptors... which will detect a inc CO2 level and inc ventilation ... causes more CO2 to be removed at the lungs - 213 things kidneys do to remove nonvolatile acids1. excrete H+ that come from nonvolatile acids
2. attempt to reabsorb all the bicarbonate ions that are filtered at the glomerulus
3. create new bicarbonate ions which then get absorbed into the circulation - 2290% of bicarbonate filtered at the glomerulus is reabsorbed in the ____proximal tubule
- 23hydrogen ions are secreted in the ___ by the ____ and in the ____ and ____ by the ______hydrogen ions are secreted into the filtrate in the proximal tubule by the Na+/H+ exchanger and in the distal tubule and collecting duct by a H+ ATP pump
- 24if the amount of H+ excreted in the urine exceeds the amount of bicarbonate reabsorbed then there will be a net ____ and the pH will ____loss of acid, pH in body will inc, becoming more basic (note this an also lead to a net lose of base, and the body can become more acidic)
- 25____, which are filtrated freely at the glomerulus into the filtrate, cannot be directly reabsorbed by tubule cellsbicarbonate ions
- 26explain how tubule cells indirectly reabsorb bicarbonate ionsbicarbonate ions must first be converted to CO2 (and water), which is then reabsorbed
- 27once in the tubule cells, CO2 combines with H2O and produces bicarbonate HCO3 and H+... what happens after?the bicarbonate ions leave the tubule cells by simple diffusion and are reabsorbed back into the circulation while the remaining H+ in the cell are secreted into the lumen by the Na+/H+ exchanger
- 28for every bicarbonate ion reabsorbed, there must be....one H+ secreted into the lumen
- 29by what mechanism are hydrogen ions secreted in the late distal tubule and collecting duct?ATP powered hydrogen ion pump
- 30ATP powered hydrogen pumplocated on the luminal side of the tubule cells and secretes one H+ for every ATP molecule consumed
- 312 types of acidosis + alkalosisrespiratory and metabolic
- 32what causes respiratory acidosisdecreased ventilation and increase pCO2 --> respiratory centers in the brain stem may be damaged or there may be lung damage, resulting in a dec ability to remove CO2 from the blood
- 33respiratory acidosis will be counteracted bybuffers in the blood and by excretion of excess H+ by the kidney
- 34respiratory alkalosis is caused byincrease in ventilation and decreased and decreased PCO2
can be caused by stress or emotionally induced by hyperventilation
high altitudes can also result in a respiratory alkalosis when the low oxygen levels in the air cause low PO2 levels in the blood which simulates hyperventilation - 35how does the body deal w respiratory alkalosisexcretion of bicarbonate from the kidney
- 36metabolic acidosis can be caused by 4 things...all these result in a dec of extracellular bicarbonate ions (does not involve inc CO2 levels in the blood)
1. kidney failure --> can't excrete acids in urine, unable to reabsorb bicarbonate from filtrate
2. formation of excess metabolic acids in the body
3. ingestion of acids (aspirin, methyl alcohol)
4. loss of bicarbonate in diarrhea (most common cause of metabolic acidosis) - 372 causes of metabolic alkalosisloss of HCl from vomiting
ingestion of alkaline drugs like sodium bicarbonate for treating ulcers
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- physiology Flashcards on C12: ACIDS AND BASES, created by mary nguyen on 04/04/2015.
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