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Flashcards do conjunto (46)
- 1What is meant by pH being a reciprocal scale?If the pH goes up, the H+ concentration goes down
- 2Where in the body is the pH the lowest?Gastric secretions
- 3What systems are involved in regulating pH?- Blood and tissue buffers
- Respiration
- Renal - long term compenation - 4What's special about the renal buffer system?It can directly excrete H+ ions from the body
- 5What are 4 examples of buffers?1. Haemoglobin
2. HCO3-
3. Inorganic phosphate
4. Weak acids/ bases on proteins - 6What type of condition: low pH and high HCO3-respiratory acidosis
When CO2 increases, shift position to the right - 7What type of condition: High pH, high HCO3-Metabolic alkylosis
Add HCO3- - 8What type of condition: Low pH, low HCO3-Metabolic acidosis, when add H+
- 9What type of condition: High pH low HCO3-When CO2 decreases
Compensate by shifting position of equilibrium to the left - 10What is rate and depth of breathing based on the partial pressures of?PO2
PCO2 and pH - 11What are the chemoreceptors stimulated by?The presence of; Hypertoxia
Hypercapnia
Acidosis - 12Where are peripheral chemoreceptors found?in carotid and aortic bodies
- 13What nerves innervate peripheral chemoreceptors?Vagus, glossopharyngeal, and sinus nerves going to the medulla and respiratory centre to increase the rate of ventilation
- 14What's the main stimulus in peropheral chemoreceptors?hypoxia
- 15What's the role of glomus cellsElectrically excitable, fire AP's when low O2
- 16What's the difference between carotid and aortic bodies?Carotid large
high flow, high metabolic rate
Aortic small, can't isolate - 17What's the mechanism in glomous cells?Inhibit K+ channels
Depolarises membrane potentials
Close channels, reach threshold, fire AP's
Open Ca2+ voltage-gated channels
increase in intracellular calcium, sitmulates fusion of vesicles containing nurotrnsmitter,
Fire AP's to medualla
Afferent nerve stimulation - 18What are the different nerurotransmitters in the glomus cells?- acetylcholine
- dopamine
- noradrenaline
- serotonin
- Subatance P
- AV peptide - 19Where are central chemoreceptors found?within the parenchyma in the brain
- 20What's the main activator in the central chemoreceptors?Increase in CO2
Hypercapnia - 21What are the central chemoreceptors bathed in and how are they separated from the arterial blood?Bathed in brain extracellular fluid
Separated by the brain, blood barrier - 22How is stimulation created from the central chemoreceptors?Increase in arteriole CO2
pH decreases
Stimulation - 23What's the bigger stimulus in the central chemoreceptors; respiratory or metabolic?Respiratory, CO2 able to cross the brain-blood barrier
Changes to the concentration of CO2 is a big stimulus - 24Where are centralchemoreceptors found?vasolateral medulla and other and other brainstem nuclei
- 25If the O2 going into the blood stream is higher, what does this mean for its response to CO2?Reduced response to CO2
- 26If there's a respiratory acidosis, CO2 change but the O2 levels are normal, which receptors are more important?Central receptors more important, but peripheral respond quicker, die off as central take over
- 27What does metabolic acidosis stimulate?Kussmaul breathing - hyperventilation
Large increase in ventilation, decrease in CO2 = increase in pH - 28What is short term acute respiratory alkalosis?If you breathe faster, CO2 levels decrease, the equation shifts to the left to compensate the lost CO2
- 29What are the 3 renal mechanisms for when there's a change in acid/alkali1. HCO3- handling
2. Urine acidification
3. Ammonia synthesis - 30Where does reabsorption of HCO3- take place?90% in the proximal tubule
10% in the distal tubule - 31Where does new bicarbonate come from?Made by the cells consequence of metabolism
- 32What two things does urine acidification allow?Maintain 25mM of HCO3-
Us to excrete H+ in urine so that is doesnt build up in plasma and lead to acidosis - 33How is NH3 made in the nephron?break down of glutamine into alpha keto-glutarate
- 34What is meant by diffusion-trapping?Separate constituents diffuses across membrane, when they combine, make NH4+, which is trapped
- 35What are the primary disorders of acid/base balance?Respiratory - lungs not able to excrete any CO2 or excrete too much
Metabolic - non-respiratory origin; kidney or other places - changes in levels of acid/base - 36What can cause a metabolic acidosis and a metabolic alkalosis?Alkalosis -decrease in acid or increase in base
acidosis - increase in acid or decrease in base - 37What is the renal composition for a respiratory acidosis?Resp system can't help as it is the cause of the problem
Renal system increases secretion of H+
Increase reabsorption of HCO3-
Lots of extra bicarbonate
Increases the pH - 38When do we get resp alkalosis?When hyperventilate - blow off too much CO2
pH increases, CO2 decreases, HCO3- decreases to compensate for decrease in CO2 - 39What's the renal compensation for resp alkalosis?Decrease H+ secretion, increase reabsorption
Decrease reabsorption of HCO3- (as it is basic)
Increases the pH - 40What conditions can cause metabolic acidosis?Diarrhea - lose alkali from the body
Diabetic ketoacidosis - excess acid in the body
CO2 normal pH decreases, HCO3- low - 41compensation for metabolic acidosisRespiratory compensation
increase the resp rate
decrease arteriole CO2
increase pH
If sustained; increase secretion of H+, increase reabsorption of HCO3- - 42Metabolic alkalosis;CO2 normal
Ingestion of alkaline or loss of acid
Vomiting - 43Compensation for metabolic alkalosisRespiratory compensation
Decrease in respiratory rate
increases in arteriole CO2
Brings pH back down towards normal - 44Asthma and acid/base regulationAsthma attack - respiratory acidosis, can't remove CO2 from the body
If cant get CO2 out cant get O2 in, anaerobic respiration, metabolic acidosis - heart stops working - 45Alcoholics and acid/base regulationMetabolic acidosis - from the breakdown of alcohol
Metabolic alkalosis - from vomiting - 46—
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- Den 103 FlashCards sobre Sem título, criado por Clelia Serra em 26-12-2016.
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