exam 2 Flashcards
Boyles law
in a closed container, pressure and volume are inversely proportional
describe volume and pressure changes during inspiration and how does the pressure affect the size of the lungs
inspiration: volume in the chest increases which results in a decrease in pressure, which creates a partial vacuum, pulling air into the lungs
describe volume and pressure changes during expiration and how does the pressure affect the size of the lungs
volume in the chest decreases, which results in an increase in pressure, pushing the air out of the lungs
what kind of pressure is found in the pleural cavity
since the chest wall and lungs are moving away from each other the volume in that space increases which causes a negative pressure in that space, negative pressure (vacuum) will cause the lungs to expand
what do the muscles of normal breathing contract and relax
the respiratory muscles contract during inspiration and relax during expiration
describes the effect of the DRG on the respiratory muscles
DRG causes inspiration so it would stimulate the respiratory muscles to contract
describes the effect of the VRG on the muscles
VRG causes forced expiration so it would prevent the contraction of the respiratory muscles and stimulate contraction of expiratory muscles
describes the effect of the apneustic center on the muscles
apneustic center increases inspiration so it would stimulate the contraction of respiratory muscles for a longer time
describes the effect of the pneumotactic center on the muscles
pneumotactic center limits inspiration so it would decrease the contraction of the respiratory muscles
what is the normal V/Q ratio
the normal ratio is 1
describe how the V/Q ratio differs for shunt vs during physiological dead space
- during a shunt, the V/Q ratio decreases
- during dead space, the V/Q ratio increases
describe the effect of the sympathetic nervous system not he bronchioles
sympathetic nervous system causes dilation of the bronchioles, increase ventilation and V/Q ratio
describe the effect of the parasympathetic on the bronchioles
parasympathetic nervous system causes constriction of the bronchioles, decreases ventilation and V/Q ratio
describe the effect of the sympathetic and parasympathetic nervous system activation on the likelihood of developing a shunt or dead space
- sympathetic nervous system = dead space
- parasympathetic nervous system = shunt
since the left lung is smaller than the right lung the volume of the space surrounding the left lung is larger than the volume of space surrounding the right lung. explain the difference in the pressure in the space surrounding the left lung vs the space surrounding the right lung and which would then be easier to inflate
- left lung is greater than the space surrounding the right lung the
- pressure in the space surrounding left lung is lower than the pressure surrounding the right lung
- left is easier to inflate
define restrictive lung disorder
problems with inspiration - breathing in
define obstructive lung disorder
problems with expiration - breathing out
give a function for DRG
pacemaker cell in the medulla that activates the normal respiratory muscles, causing inspiration
give a function for apneustic center
pacemaker cell in pons increases the activity of the DRG prolonging inspiration
give a function for pneumotactic center
pacemaker cell in pons decreases activity of the DRG limiting inspiration
give a function for VRG
pacemaker cell in medulla that only become active when air must be forced out of the lungs
describe how the activity of each of these respiratory pacemakers would different for a restrictive disorder vs obstructive disorder
- restrictive disorder: need to have increased DRG activity, caused by increased activity of the apneustic center and decreased activity of pneumotactic center
- obstructive disorder: would need to have decreased DRG activity which would be caused by decreased activity of the apneustic center and increased activity of the pneumotactic center; it would also require the VRG
give the chemical equation
CO2 + H2O <–> H2CO3 <–> H + HCO3
what is the enzyme needed to drive the reaction tot he right
carbonic anhydrase is the enzyme )located in erythrocytes) to drive the reaction left
describe the effect of the direction of the reaction on blood pH
- right = blood pH decreases
- left = blood pH increases
describe the effect of breathing into a paper bag vs hyperventilation on blood pH
- paper bag = lower blood pH
- hyperventilation = raises blood pH
describe the effect of breathing into a paper bag vs hyperventilation on the activity of the enzyme from
- paper bag = raises CO2 levels and increase carbonic anhydrase activity
- hyperventilation = lowers CO2 levels and decrease carbonic anhydrase activity
compare volatile vs nonvolatile acids
convert to CO2 (Yes or no)
- nv = no
- v = yes
removal from body (kidneys or lungs)
- nv = kidneys
- v = lungs
time course for removal (hours or minutes)
- nv = hours
- v = minutes
chemoreceptor responsible for detection (central or peripheral)
- nv = peripheral
- v = central
What is the difference in the affinity for O2 of the alpha and the beta chains
Alpha chains have a higher affinity for O2 than the beta chains
What are the 2 variables that affect the ability of materials in the blood to pass through the filter during filtration at the glomerulus of the kidney
size (in an inverse relationship) and electric charge (positive charges pass more easily than negative charges
which of the following ions would be more easily filtered: H or HCO3
H is a small positive charged ion and should pass more easily through the filter than HCO3 which is larger negatively charged
What consequences would this have on blood pH
Allowing H to pass through the filter, while preventing the filtration of HCO3 will raise blood pH
Why would it be important to retain one of those ions and excrete the other
- H ions are acids, in particular volatile acids, so these need to be removed from the blood.
- HCO3 ions are important buffers in blood, so they should be retained
Prolonged vomiting can produce a drop in blood sodium (Na) levels, a condition known as hyponatremia. Na reabsorption is tied to H secretion in the DCT. How might hyponatremia affect blood pH
Hyponatremia would decrease H secretion, which would lower blood pH
What would this be an example
of: metabolic acidosis, metabolic alkalosis, respiratory acidosis or respiratory alkalosis? Describe any compensation for this condition, including the time course (minutes or hours)
Compensation for this would be to
try to increase the rate of respiration, which would take only minutes
Prolonged vomiting can produce a drop in blood sodium (Na) levels, a condition known as hyponatremia. Describe how the macula dense cells might affect the diameter of the afferent arteriole
Macula densa cells, sensing a decrease in Na+, would interpret that as a decrease in GFR. In response, they would release NO, which would cause the afferent arteriole to dilate, raising GFR.
What is the function of the hormone
aldosterone? Describe how aldosterone secretion might change in response to
hyponatremia
Aldosterone is a hormone that acts on
the DCT, increasing the reabsorption of Na, leading to an increase in blood Na levels. Aldosterone secretion should increase in response to hyponatremia.
table on changes in the activity of the enzyme in the pCT and the DCT for each of the conditions
metabolic acidosis (volatile acid
- DCT = no change
- PCT = no change
metabolic acidosis (nonvolatile acid)
- DCT = increased activity
- PCT = no change
metabolic alkalosis
- DCT = no change
- PCT = no change
respiratory acidosis
- DCT = increased activity
- PCT = no change
respiratory alkalosis
- DCT = decreased activity
- PCT = no change
Define renal clearance
The volume of blood from which a substance is removed per unit time
Describe how renal H+ clearance for each of the
following:
- metabolic alkalosis
- metabolic acidosis (volatile acidosis)
- metabolic acidosis (nonvolatile acid)
- respiratory alkalosis
- respiratory acidosis
- Metabolic alkalosis: No change in renal clearance of H+.
- Metabolic acidosis (volatile acid): No change in renal clearance of H+.
- Metabolic acidosis (nonvolatile acid): Increased renal clearance of H+.
- Respiratory alkalosis: Decreased renal clearance of H+.
- Respiratory acidosis: Increased renal clearance of H+.
Describe differences in the amount of reabsorption in the PCT versus the DCT
The amount of reabsorption is higher in the PCT compared to the DCT
Describe differences in the variability of reabsorption in the PCT versus the DCT
Conversely, the variability of reabsorption is lower in the PCT compared to the DCT
Describe the effect on blood pressure if the amount of reabsorption remained the same but the variability of absorption were switched between the PCT and the DCT
If the amount of fluids reabsorbed in PCT and DCT remained the same but the amount of variability were switched between the two, blood pressure would experience very large fluctuations.
question 1
- internal = between blood and lungs
- external = between blood and tissue
- CO2 leaves the lungs and raises pH and increases affinity for external
- CO2 enters the blood and lowers pH and lowers affinity for internal
question 2
- left = CO2 leaving blood in external respiration
- right = CO2 entering blood in internal respiration
question 3 - how does yawning affect pulmonary ventilation
- yawning = large inhale and large exhale
- increases inspiration
- when you breathe in hard you use the breathing muscles more
question 4
- pacemakers:
- VRG and DRG in medulla
- pneumotactic center and apneustic center in pons
- large ins[iration activates activity in DRG and do that by increasing apneustic center activity/decreasing pneumotactic activity
question 5
non volatile acids stimulate peripheral chemo receptors because nonvolatile acids can’t cross the blood brain barrier so they get trapped in the blood
question 6
- shunt: V/Q ratio drops because there is more blood flow than air flow (more blood flow = more CO2)
- dead space: V/Q ratio increases because there is more air flow than blood flow (more air flow = more O2)
question 7
no atmospheric pressure in space which means is easy to breathe out but hard to breathe in and that causes a restrictive lung disorder
question 8
absorbing more amino acids you that by absorbing more sodium which causes there to be less sodium left and causes the macula dense to think GFR has dropped so it releases nitrous oxide causing the afferent arteriole to dilate
question 9
- size of afferent arterioles is directly proportional to GFR
- when the afferent arterioles dilate the GFR goes up when it constricts GFR goes down
- nitric oxide is released and makes the arteriole dilate and adenosine makes it constrict
- low sodium diet makes the macula dense think GFR dropped so it would release nitric oxide and make your afferent arteriole dilate
question 10
- net filtration pressure is the total of all pressure
- determines where fluid moves (moving into or out of the blood)
- when net filtration pressure causes infiltration, which its negative you get reabsorption and glomerulus is the site of filtration and have a positive net filtration
question 11
- blood pH + log HCO3/CO2
- HCO3 = kidney
- CO2 = lungs
- normal blood pH is 7.34-7.45
- acidosis = drop in HCO3 or increase in CO2
- alkalosis = increase in HCO3 or drop in CO2
question 12
- descending limit is reabsorbed water and would make the fluids inside hypertonic
- ascending limit is reabsorbed salt and that would make the fluids hypertonic
question 13
- renal clearance = rate which or the volume of blood from which you remove stuff; ‘clear’ance = clear from body
- renal clearance for acid
- metabolic acidosis (volatile acid) = no change b/c its a volatile acid; change by breathing faster
- metabolic acidosis (with nonvolatile acid) = would make clearance go up
- metabolic alkalosis = no change
