Card Set Information

2010-10-07 23:30:37
renal cardiovascular pulmonary

Kidneys, heart, & lungs
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  1. major functions of the kidney
    regulation of water & electrolyte balance; regulation of arterial blood pressure; maintenance of acid/base balance & excretion of metabolic waste; excretion of foreign substances; regulation of red blood cell production; regulation of the active form of vitamin D
  2. major structures of the kidney
    cortex; medulla; minor calyx; major calyx; renal pelvis
  3. major function of the glomerulus
    filtration - barrier between inside and outside world; allows small molecules & water through to filtrate while preventing exit of red blood cells & proteins from the blood
  4. major function of the proximal tubule
    reabsorption; most water and salt absorption takes place here
  5. major function of the loop of Henle
    creation of concentration gradient in kidney medulla
  6. major function of the collecting duct
    fine-tuning of absorption/secretion
  7. anatomy of the nephron
    glomerulus (cortex) -> proximal convoluted tubule (cortex) -> proximal straight tubule (outer medulla) -> thin descending loop of Henle (outer medulla) -> thin ascending LOH (inner medulla) -> thick ascending LOH (outer medulla) -> juxtoglomerular apparatus (cortex) -> distal convoluted tubule (cortex/outer medulla) -> connecting segment (cortex) -> cortical collecting duct -> medullary connecting duct
  8. blood supply of nephron
    peritubular capillaries (proximal tubule); vasa recta (lie parallel to loop of Henle)
  9. main cell types of the glomerulus
    endothelial; mesangial; podocyte
  10. endothelial cells of the glomerulus
    fenestrated; line the capillaries of the glomerulus; comprise first layer of filtration (very broad; allows entry of many substances)
  11. mesangial cells
    found in the central part of the glomerulus between capilary loops; produce negatively charged basement membrane (2nd layer of filtration -> charge filtration)
  12. podocyte cells
    "comprise 3rd and most selective layer of filtration; have processes (""fingers"") that extend into basement membrane; thin processes called slit diaphrams bridge gaps between ""fingers"""
  13. factors affecting ultrafiltration
    hydrostatic & plasma oncotic & capsular hydrostatic pressure and resistance (flow = pressure difference/resistance); afferent arteriole slightly larger than efferent arteriole -> increased pressure
  14. glomerular filtration rate
    the amount of blood filtered from the capillary into the glomerular capsule; is directly proportional to net filtration pressure (GFR = Kf * NFP)
  15. regulation of GFR
    by 3 mechanisms: autoregulation (mediated by vascular smooth muscle tone of arterioles) & autonomic regulation from the CNS -> regulation of blood flow & tubuloglomerular feedback -> regulation of blood flow or mesangial cell size
  16. ADH
    antidiuretic hormone (vasopressin); released by the pituitary gland; overall - concentrates urine; increases water permeability of cells in the collecting duct; enhances urea transport to the interstitium; increases sodium uptake in the thick ascending loop of Henle
  17. aldosterone
    mineral corticoid; responsible for salt and water reabsorption; secreted by the adrenal glands; decreases plasma sodium and increases plasma potassium/ACTH/angiotensin II; when bound to receptor -> translocation to nucleus of collecting duct cell -> action as a transcription factor
  18. aquaporin-2
    receptor found in cells of the collecting duct; ADH binding activates a cascade that causes translocation to the membrane; permeable to water
  19. aldosterone receptor
    can interact with other steroid hormones; enzyme 11-beta-HSD decreases affinity of other steroids to the receptor
  20. natriuresis
    the process of sodium excretion; leads to increased water excretion; regulates blood pressure and volume
  21. diuresis
    the process of water excretion; regulates blood pressure and volume
  22. granular cells
    smooth muscle cells found in the afferent arterioles of the glomerulus; act as baroreceptors; synthesize and secrete renin
  23. macula densa
    portion of the thick ascending limb in close contact with the glomerulus; acts as a sodium sensor; influences renin production to regulate blood pressure
  24. CNS regulation of blood pressure
    baroreceptors in the CNS assess blood pressure and act via the renal sympathetic nerve to affect renin production
  25. renin
    enzyme produced by granular cells in response to low blood pressure; act on angiotensinogen to convert angiotensin I to angiotensin II
  26. angiotensin II
    increases blood volume by acting directly on arteriolar/vascular smooth muscles to increase cardiac output & increasing sympathetic CNS activity & stimulating the pituitary to release ADH & stimulating the release of aldosterone
  27. hypoosmotic
    contains less solute than surrounding fluid (less osmotic pressure)
  28. hyperosmotic
    contains more solute than surrounding fluid (more osmotic pressure)
  29. conducting zone of the lung
    includes trachea & bronchi & bronchioles; involved in warming & humidifying air; protects airway through actions of cilia and mucous; no respiratory exchange takes place
  30. respiratory zone of the lung
    includes respiratory bronchioles & alveoli; involved in gas exchange
  31. determination of physiological dead space
    dead space = volume of air that does not contribute CO2 to expired air; can calculate using Bohr equation (knowing volume of exhaled air and partial pressure of CO2 in alveoli)
  32. determination of TLC
    total lung capacity; can be determined using helium dilution of exhaled air
  33. determination of TV
    tidal volume (amount inhaled/exhaled in a normal breath); use spirometer
  34. determination of VC
    vital capacity (amount of air one is able to expel in a full forceful breath); use spirometer
  35. determination of FRC
    functional residual capacity (volume left in the lungs after a normal breath); can be determined using helium dilution of exhaled air
  36. determination of RV
    residual volume (volume left in the lungs after a forceful exhalation); can be determined using helium dilution of exhaled air
  37. effect of alveolar ventilation on alveolar O2
    increased alveolar ventilation -> increased O2; decreased V -> decreased O2
  38. effect of alveolar ventilation on alveolar CO2
    increased alveolar ventilation -> decreased CO2; decreased AV -> increased CO2
  39. muscle actions during inspiration and expiration
    quiet breathing: inspiration - external intercostals contract & raise ribs; diaphragm contracts and lowers. Forceful breathing: inspiration - sternocloidomastoids as well; expiration - internal intercostals & abdominal muscles
  40. function of negative interpleural pressure
    keeps alveoli from collapsing
  41. Laplace's Law
    pressure = (2*surface area)/r
  42. influence of surfactant on lung compliance
    increases lung compliance by decreasing surface tension of fluid
  43. functions of pulmonary surfactant
    decreases the surface tension of fluid in order to decrease pressure on the alveoli/decrease resistance
  44. elastic components associated with the work of breathing
    compliance work against elastic tissues & surface tension of the lung
  45. frictional components associated with the work of breathing
    tissue-against-tissue sliding; air through airways
  46. partial pressure of gas within a liquid
    the partial pressure of a hypothetical gas phase with which the liquid would be in an equilibrium state
  47. conditions that change hemoglobin affinity for oxygen
    affinity drops under increased temperature & increased acidity & increased partial pressure of CO2 & increased levels of 2 3 diphosphoglycerate (increases during anaerobic glycolysis) - anything requiring release of O2 from hemoglobin
  48. chemical forms of O2 and approximate percentages in blood
    combined with hemoglobin & dissolved
  49. chemical forms of CO2 and approximate percentages in blood
    dissolved in blood; combined with protein as carbamino compounds; combined with water to form bicarbonate ions (90%)
  50. respiratory exchange ratio
    average output of CO2 divided by the average intake of O2; under normal conditions is about 80%
  51. Henderson-Hasselbalch equation for CO2 & bicarbonate
    pH = 6.1 +(log[HCO3])/(0.03 x pCO2)
  52. metabolic acidosis/alkalosis
    metabolic acidosis = HCO3- levels are too low; alkalosis = HCO3- levels are too high
  53. respiratory acidosis/alkalosis
    respiratory acidosis = CO2 levles are too high; alkalosis = CO2 levels are too low
  54. renal handling of bicarbonate
    most bicarbonate is reabsorbed in the proximal tubule; bicarbonate can be regenerated in the Type A intercalated cells of the collecting duct
  55. renal response to acid load
    Type A intercalated cells of the proximal tubule involved in secretion of hydrogen ions (bicarbonate reabsorbed -> interstitium and H+ -> lumen); bicarbonate regenerated using phosphate or ammonia as proton acceptors
  56. renal response to alkali load
    Type B intercalated cells of the proximal tubule involved in secretion of base (release bicarbonate -> lumen and H+ -> interstitium via H+/K+ pump)
  57. importance of urea recycling
    contributes about 50% of interstitial osmolarity at tip
  58. mechanisms of creation of a hyperosmotic medullary interstitium
  59. right-to-left pulmonary shunt
    in healthy people - shunts 1-2% blood from the right to the left ventricle without making contact with alveolar air; teratology of Fallot is an inappropriate R-to-L shunt (results in right-left septal defect & right ventricle -> aorta defect & stenosis of pulmonary artery & hypertrophied right ventricle)
  60. maximum & minimum & mean pulmonary artery pressure
    max=25; min=8; average = 15
  61. maximum & minimum & mean aortic pressure
    max=120; min=75
  62. resistance to flow in pulmonary vs. systemic blood vessels
    much lower resistance to blood flow in pulmonary vs. systemic blood vessels
  63. causes and consequences of pulmonary capillary vessel recruitment and retention
    mechanism to reduce resistance in the pulmonary capillaries in order to deal with increases in cardiac output; recruitment = allowing blood to flow through more (normally bypassed) capillaries; distension = increasing radius of capillaries
  64. zones of blood flow
    zone I = alveolar pressure greater than arterial and venous (pathological); zone II = alveolar pressure is less than arterial but greater than venous (blood flows in pulses) - top of heart; zone III = alveolar pressure lower than arterial and venous (blood flow continuous) - most of heart
  65. perfusion and ventilation in lung regions
    perfusion & ventilation = greater @ bottom of lung due to gravity; pressure = higher; alveoli = smaller
  66. location of chemoreceptors
    central chemoreceptors = in brainstem; peripheral chemoreceptors = in aortic arch and @ bifurcation of carotid artery
  67. function of chemoreceptors
    central - detect CO2 via pH changes in CSF; peripheral - detect O2 & CO2 & pH (carotid receptors only)
  68. central controller location
    pons/medulla = vasomotor region
  69. parameter dominating control of ventilation under normal conditions
  70. lung mechanoreceptors
    slowly adapting stretch receptors in large & small airways (respond to lung inflation -> prevention of overinflation); rapidly adapting receptors in airways (respond to mechanical/chemical irritation ->cough/bronchoconstriction); J-receptors in alveolar walls (respond to pulmonary embolism/vascular congestion -> tachypnea & dyspnea)
  71. hysteresis
    the difference between the transpulmonary pressure vs. volume curve for inhalation and exhalation (volume is less for a given pressure durng inhalation vs. exhalation)
  72. tachypnia
    rapid shallow breathing
  73. dyspnea
    sensation of shortness of breath