Exam 3

  1. What is the difference between internal and external respiration
    • Internal: Metabolic process occurring in the mitochondria
    • External: Exchange of O2 and CO2 between the external environment and cells
  2. What are the 3 types of cells in alveoli and what is each of their primary functions
    • Type 1: Rapid gas exchange
    • Type 2: Secretes surfactant
    • Alveolar macrophage: aids in removal of any foreign substance
  3. What causes air to enter and leave the lungs
    • Enters: Intra alveolar pressure lower than the atmospheric pressure
    • Exits: Intra-alveolar pressure is greater than the atmospheric pressure
  4. Describe Boyle's Law
    The pressure of gas is inversely related to its volume
  5. Describe 3 important pressure gradients necessary for respiration to take place
    • Atmospheric pressure: 760 mmHG
    • Intra-Alveolar pressure: Rapidly equilibrates with atmospheric pressure
    • Intrapleural pressure: Averages 4 mmHG less than atmospheric pressure
  6. List and describe the 6 respiratory muscles
    • Inspiration: Diaphragm, external intercostals, sternocladomastoid, and scalenous
    • Expiration: Abdominal and internal intercostals
  7. What variables control air flow in and out of the lungs/. What controls these variables?
    • Change in pressure gradients and resistance
    • Controlled by the autonomic nervous system
  8. What is the tidal volume
    Amount of air entering of leaving the lungs during each breath
  9. What 3 forces prevents alveoli from collapsing
    • Transmural pressure gradient
    • Pulmonary surfactant
    • Alveolar interdependance
  10. What is the different between pulmonary and alveolar ventilation
    • Pulmonary ventilation: Not all air inspired reaches the alveoli 
    • Alveolar ventilation: All of the air that reaches the alveoli
  11. List 2 reasons why PO2 in the alveolar air is different from atmospheric air
    • Saturation with water
    • Mixing with dead space that remains after expiration
  12. Explain why oxygen diffuses from the alveoli into the pulmonary capillaries and why carbon dioxide does the opposite
    PO2 is greater in alveoli than capillaries so the pressure gradient makes it diffuse from alveoli to capillary and does the opposite for CO2
  13. What 2 ways is oxygen transported in the blood
    • Dissolved
    • Chemically bound to hemoglobin
  14. What effect does carbon monoxide have on Hb?
    • Competes with O2 for binding site
    • O2 has greater affinity so it takes up all Hb molecule bonds
  15. List 3 ways CO2 is carried in bloodstream
    • Dissolved in plasma (10%)
    • Bound to Hb (30%)
    • Transported as bicarbonate (60%)
  16. Describe what the dorsal respiratory group (DRG) and VRG do to regulate respiration
    • DRG: Controls normal breathing
    • VRG: Enhances respiration in time of need, forced breathing
  17. What is the function of the pre-Botzinger region of the medulla
    Controls pacemaker activity
  18. What role do the pneumotaxic and apneustic centers of the pons have in regulating respiration
    • Pneumotaxic: Slows down DRG and causes less respiration
    • Apneustic: Increases ventilation
  19. What is the primary chemical factor that regulates the medullary respiratory center
  20. List the 3 steps to urine formation
    • Glomerular filtration
    • Tubular absorption
    • Tubular secretion
  21. List the tubular components to the nephron
    • Bowman's capsule
    • Proximal tubule
    • Distal tubule
    • Loop of henle
    • Collecting duct
  22. List the vascular components of the nephron
    • Afferent arteriole
    • Efferent arteriole
    • Glomerulus
    • Peritubular capillaries
  23. What 3 barriers are there to glomerular filtration
    • Endothelium of glomerular capillaries
    • Basement membrane
    • Inner layer of bowman's capsule
  24. GFR is a product of what 2 factors
    • Filtration pressure
    • Filtration coefficient
  25. What forces regulate glomerular filtration rate and which one is more easily manipulated when the kidney is attempting to regulate the GFR
    • Hydrostatic and Oncotic
    • Hydrostatic is easily manipulated
  26. Describe the JGA
    • Tubuloglomerular feedback mechanism in intrinsic auto regulation 
    • Senses change in flow
  27. List 5 barriers to transcellular transporting during tubular reabsorption and secretion
    • Luminal cell membrane
    • Cytosol
    • Basolateral cell membrane
    • Interstitial fluid
    • Capillary wall
  28. Describe constant versus variable sodium reabsorption
    • Constant: Amount of Na+ reabsorbed never changes
    • Variable: Amount of Na+ being reabsorbed is subject to hormonal control
  29. Describe the process of active sodium reabsorption
    • Begins at proximal tubule: 67% Na+ absorbed. Constant
    • Ascending limb: 25% Na+ reabsorbed. Constant
    • Distal tubule and collecting duct: 0-8% Na+ reabsorbed. Variable
    • Na+/K+ ATPase pump: Keeps sodium concentration low in tubular cells
    • H2O: follows reabsorbed sodium by osmosis
  30. Where is renin released from?
    Granular cells
  31. Describe RAAS
    • Granular cells secrete renin to increase sodium reabsorption  indirectly
    • Renin+Angiotensinogen (iver) -> Angiotensin I+ACE (lungs) -> Angiotensin II
    • Increase in blood pressure when it becomes too low
  32. List the 4 functions of angiotensin
    • Systemic vasoconstriction
    • Stimulates Thirst
    • Stimulates ADH from P.P
    • Stimulates aldosterone from adrenal cortex
  33. What does atrial natriuretic peptide (ANP) do?
    • Prevents retention of Na+
    • Produced by heart when stretched
    • Inhibits Na+ reabsorption and promotes diuresis
    • Decreases blood pressure when becomes elevated
  34. What does ADH do
    • Increases water reabsorption 
    • Causes less urination
  35. How does aldosterone work
    Increases sodium reabsorption by Na+ channels and Na+/K+ pump
Card Set
Exam 3