Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Pulmonology > Respiratory Physiology Part 3 > Flashcards

Respiratory Physiology Part 3 Flashcards

1
Q

What is the difference between external and internal respiration ?

A 
External respiration (lungs)
Internal respiration (body tissues)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Basic Properties of Gases: What is Dalton’s Law of Partial Pressures?
2

Equation?

A

Total pressure exerted by a mixture of gases is the sum of the pressures exerted by each gas

The partial pressure of each gas is directly proportional to its percentage in the mixture

Total Pressure = P1 + P2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What happens to gravity when you increase the altitude?

For example at 10,000ft the atmospheric pressure wound not be 760mmHg let’s suppose it is 523mmHg. If we change that here then how does that change affect the partial pressure of oxygen? Work out the math:

A

It decreases.

0.209 x 523 = 109 mmHg at sea level.

Ex: (0.786 x 760 = 597)
Ex: (0.209 x 760 = 159)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is Henry’s law?

The amount of gas that will dissolve in a liquid also depends on what? 2

A

Gas will dissolve in a liquid in proportion to its partial pressure

it’s solubility and temp of the liquid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

The direction and the movement of a gas are determined by it’s?

What happens when the partial pressure of CO2 is higher in the pulmonary capillaries than in the lungs?

Clinical application example?

A

partial pressure

will move into the lungs

Hyperbaric chamber- increase environmental pressure graident of oxygen so oxygen will be driven into the tissues and help facilitate wound healing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Alveoli contain more CO2 and water vapor than atmospheric air.
This is due to?
3

A
  1. Gas exchange in the lungs
  2. Humidification of air
  3. Mixing of alveolar gas that occurs with each breath
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Partial pressure gradient for O2 in the lungs is described as?

Venous blood Po2 = ___ mm Hg
Alveolar Po2 = ____ mm Hg

O2 partial pressures reach equilibrium of ___ mm Hg in ~___ seconds, about ___ the time a red blood cell is in a pulmonary capillary

A

steep

40
104

104
0.25
1/3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the CO2 partial pressure gradient in the lungs compared to that of O2?

Venous blood Pco2 = __ mm Hg
Alveolar Pco2 = __ mm Hg

CO2 is __ times more soluble in plasma than oxygen
CO2 diffuses in _____ amounts with oxygen

A

less steep

45
40

20
equal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is ventilation?
What is perfusion?

How must they relate for efficeint gas exchage?

A

Ventilation: amount of gas reaching the alveoli
Perfusion: blood flow reaching the alveoli

Ventilation and perfusion must be matched (coupled, i.e. working together) for efficient gas exchange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Influence of local PO2 on perfusion:
1. Changes in PO2 in the alveoli cause changes in what?

  1. Where alveolar O2 is low, arterioles what? In an attempt to what?
  2. Where alveolar O2 is high, arterioles what? In an attempt to what?
  3. What is another name for this phenomenon?
A
  1. the diameters of the arterioles
  2. Where alveolar O2 is low, arterioles constrict
    In an attempt to redirect blood to areas where PO2 is higher
  3. Where alveolar O2 is high, arterioles dilate
    Increase blood flow into the area to pick up the O2
  4. shunting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Influence of local PCO2 on ventilation:
1. Changes in Pco2 in the alveoli cause changes in what?

  1. Where alveolar CO2 is high, bronchioles what? Allowing what?
  2. Where alveolar CO2 is low, bronchioles what?
A
  1. the diameters of the bronchioles
  2. Where alveolar CO2 is high, bronchioles dilate
  3. Allowing CO2 to be eliminated
    Where alveolar CO2 is low, bronchioles constrict
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the thickness and area of the respiratory membrane?

A

0.5 to 1 μm thick

Large total surface area (40 times that of one’s skin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What would make the respiratory membrane thicker?

What would reduce the surface area and whats happening during this time?

A

Thickens if lungs become

  1. waterlogged and
  2. edematous, and
  3. gas exchange becomes inadequate

Reduction in surface area with emphysema, when walls of adjacent alveoli break down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

INTERNAL RESPIRATION
Partial pressures and diffusion gradients are _____ compared to external respiration

Po2 in tissue is always _____ than in systemic arterial blood

Po2 of venous blood is ___ mm Hg and Pco2 is __ mm Hg

A

reversed

lower

40
45

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

O2 is transported 2 ways in the blood. What are they?

also in what percentage is it found in each

A

1.5% dissolved in plasma

98.5% loosely bound to each Fe of hemoglobin (Hb) in RBCs
4 O2 per Hb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Hemoglobin-O2 combination
is what?

Hemoglobin that has released O2 is called what?

Describe the chemical reaction these two structures participate in?

A

Oxyhemoglobin (HbO2)

Reduced hemoglobin (HHb)

HHb + O2 {Lungs and Tiisues} HbO2 + H+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

As O2 binds, Hb affinity for O2____?

As O2 is released, Hb affinity for O2 ___?

Hemoglobin is Fully (100%) saturated if what?

Hemoglobin is partially saturated if what?

A

increases

decreases

Fully (100%) saturated if all four heme groups carry O2

Partially saturated when one to three hemes carry O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Loading and unloading of O2 is facilitated by what?

A

change in shape of Hb

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Rate of loading and unloading of O2 is regulated by

5

A
  1. (partial pressure of O2) Po2
  2. Temperature
  3. Blood pH
  4. PCO2
  5. Concentration of BPG
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Concentration of BPG rises when what happens?

A

O2 uptake in the lungs is compromised (altitude and obstructive lung disease)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The binding and release of O2 is influenced by it’s what?

Describe the Oxygen-hemoglobin dissociation curve?

A

partial pressure

Hemoglobin saturation plotted against Po2 is not linear
S-shaped curve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What kind of blood has the highest rate of saturated hemoglobin?

Whats the PO2?
Hb is how saturdated?

A

arterial blood

Po2 = 100 mm Hg
Hb is 98% saturated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Hb saturation is lower in the venous blood due to what?

In venous blood
Po2 is?
Hb is?

A

oxygen uptake by the tissues.

In venous blood
Po2 = 40 mm Hg
Hb is 75% saturated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Hemoglobin is almost completely saturated at a Po2 of ___?

Further increases in Po2 produce ______ in O2 binding?

O2 loading and delivery to tissues is adequate when PO2 levels are what?

A

70 mmHg

Only small increases

below normal levels (get in and out of the taxi even faster)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Only ____% of bound O2 is unloaded during one systemic circulation

If O2 levels in tissues drop what will happen? 2

A

20–25

  1. More oxygen dissociates from hemoglobin and is used by cells
  2. Respiratory rate or cardiac output need not increase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Other Factors Influencing Hemoglobin Saturation? 4

Decreases in these factors shift the curve to the what?

A

Increases in

  1. temperature,
  2. H+(decreased pH),
  3. Pco2, and
  4. BPG

left

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What will Increases in temperature, H+(decreased pH), Pco2, and BPG do? 3

Where will this occur?

A
  1. Modify the structure of hemoglobin and decrease its affinity for O2
  2. . Enhance O2 unloading
  3. Shift the O2-hemoglobin dissociation curve to the right

Occur in systemic capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What are BPG levels produced by?

How does it bind to Hb?

When does BPG increase?

A

red blood cells as they break down glucose through glycolysis

reversibly

When oxygen levels are chronically low

29
Q

How does BPG affect the affinity of O2 for Hb?

What does this allow?

A

Decreases affinity of O2 for Hb allowing the O2 to be released (unbound)

so that it can go to tissues where needed

30
Q

As cells metabolize glucose the affinity for oxygen to hemoglobin changes.

Cellular respiration: cells metabolize glucose, use __ and release ___?

Therefore the ___ and ___ increase in concentration in capillary blood = ____?

Declining pH ______ the hemoglobin-O2 bond (Bohr effect) so that O2 is _______here (in the tissues where it is most needed)

A

O2 and release CO2

PCO2 and H+
↓pH

weakens
unloaded

31
Q

Heat production _______ (by product of metabolism)

Increasing temperature directly and indirectly ______ Hb affinity for O2

A

increases

decreases

32
Q

What is Inadequate O2 delivery to tissues?

What could this be due to?
6

A

hypoxia

  1. Too few RBCs (anemia)
  2. Abnormal or not enough Hb
  3. Blocked circulation (pump failure or emboli)
  4. Metabolic poisons (cyanide)
  5. Pulmonary disease (abnormal ventilation)
  6. Carbon monoxide (takes up the O2 binding sites on Hb)
33
Q

CO2 is transported in the blood 3 ways.

What is the majority transported as?????????

A
  1. Dissolved in plasma (7-10%)
  2. Bound to hemoglobin (carbaminohemoglobin) (20%)
    - –Binds on a different site compared to O2
  3. Transported as bicarbonate ions (HCO3–) in plasma (70%)**
34
Q

CO2 combines with water to form what?

Describe its dissociation

Where does this mostly occur and what works to do this?

A

carbonic acid

 CO2 Carbon
dioxide
\+
H2O Water
↔
H2CO3  Carbonic Acid
↔
H+ Hydrogen ion
\+
HCO3–  Bicarbonate ion

RBC,
carbonic anhydrase reversibly and rapidly catalyzes the reaction

35
Q

In systemic capillaries
HCO3– quickly diffuses from where to where?

Describe the chloride shift?
2

A

RBCs into the plasma

The chloride shift occurs:

  1. outrush of HCO3– from the RBCs is balanced
  2. as Cl– moves in from the plasma
36
Q

Describe transport and exchange of CO2 in the pulmonary capillaries (the level of the lungs)
3 steps

A

In pulmonary capillaries
1. HCO3– moves into the RBCs and binds with H+ to form
H2CO3 (carbonic acid)
2. H2CO3 is split by carbonic anhydrase into CO2 and water
3. CO2 diffuses into the alveoli

37
Q

Three ways CO2 is transported into the lungs and also into the tissue?

A
  1. Dissolved in plasma
  2. Transported bound with hemoglobin
  3. Transported as HCO3
38
Q

What is the Haldane effect?

A

The amount of CO2 transported is affected by the PO2

The lower the PO2 and hemoglobin saturation with O2, the more CO2 can be carried in the blood

39
Q

At the tissues, as more carbon dioxide enters the blood, oxygen reacts how?

As HbO2 releases O2, it more readily does what?

A

More oxygen dissociates from hemoglobin (Bohr effect)

forms bonds with CO2 to form carbaminohemoglobin

40
Q
  1. What is the alkaline reserve of the carbonic acid–bicarbonate buffer system?
  2. If H+ concentration in blood rises what happens?
  3. If H+ concentration begins to drop what happens?
  4. What is the equation for this phenomanon?
A
  1. HCO3– in plasma
  2. excess H+ is removed by combining with HCO3–
  3. H2CO3 dissociates, releasing H+
  4. CO2 + H2O -> H2CO3 -> HCO3- + H+

(first arrow is carbonic anhyrdrase- catalyst)

41
Q

Influence of CO2 on Blood pH

Changes in respiratory rate can also alter blood pH
For example, slow shallow breathing allows ____to accumulate in the blood, causing pH to ____?

Changes in _______ can be used to adjust pH when it is disturbed by metabolic factors

A

CO2
drop

ventilation

42
Q
  1. _________ ____ and _________ work to regulate blood pH.
  2. If H+ concentration in the blood rises, excess ____ is removed by combining with ______ to form ______ ___ and blood pH _____.
  3. If H+ concentration in the blood goes too low then_______ ____ dissociates and becomes _____and the pH ________.
A
  1. Hydrogen ions
    bicarbonate
2. 
H+
HCO3-
carbonic acid
lowers (more acidic)
  1. carbonic acid
    HCO3-
    increases (more alkalotic).
43
Q

What neurons control respiration?

A 
neurons in the reticular formation of the medulla and pons
Medulla
-Ventral respiratory group (VRG)
-Dorsal respiratory group (DRG)
Pons
-Pontine respiratory group
44
Q

What chemical factors influence neuron control of respiration? 3

What two other things affect neuron control of respiration?

A

Arterial pH, PO2 and PCO2

Lung reflexes
Emotions (anxiety and pain)

45
Q

What does the Dorsal respiratory group (DRG) do?

A

Integrates input from peripheral stretch and chemoreceptors

46
Q

What does the Ventral respiratory group (VRG) do?

4

A
  1. Rhythm-generating and integrative center
  2. Sets eupnea (12–15 breaths/minute)
  3. Inspiratory neurons excite the inspiratory muscles via the phrenic and intercostal nerves
  4. Expiratory neurons inhibit the inspiratory neurons
47
Q

Pontine respiratory centers do what?

2

A
  1. Influence and modify activity of the VRG

2. Smooth out transition between inspiration and expiration and vice versa

48
Q
  1. HOw is depth of breathing determined?
  2. How is rate determined?
  3. Both are modified in response to what?
A
  1. Depth is determined by how actively the respiratory center stimulates the respiratory muscles
  2. Rate is determined by how long the inspiratory center is active
  3. Both are modified in response to changing body demands
49
Q

Chemical factors that PCO2 influences and thus breathing:

  1. If PCO2 levels rise (hypercapnia)?
  2. CO2 is hydrated?
  3. H+ stimulates the central chemoreceptors of the what?
  4. H+ stimulates the peripheral chemoreceptors and result in _____ the depth and rate of breathing
A
  1. CO2 accumulates in the brain
  2. resulting carbonic acid dissociates, releasing H+
  3. brain stem
  4. increasing
50
Q
  1. What is hyperventilation?
  2. How will CO2 levels react?
  3. –what may this cause? 2
A
  1. increased depth and rate of breathing that exceeds the body’s need to remove CO2
  2. Causes CO2 levels to decline (hypocapnia)
  3. May cause cerebral vasoconstriction and cerebral ischemia
51
Q

What is apnea?

A

period of breathing cessation that occurs when PCO2 is abnormally low

(this will reset the hyperventilation- stop breathing will let CO2 build up)

52
Q

Where are our O2 sensors at that regulate PO2? 2

When excited what do these respiratory centers do?

A

Peripheral chemoreceptors in the aortic and carotid bodies

increase ventilation

53
Q

What must occur in order to stimulate increased ventilation?

A

Substantial drops in arterial PO2 (to 60 mm Hg)

54
Q

Can pH modify respiratory rate and rhythm even if CO2 and O2 levels are normal?

A

yes

55
Q

Decreased pH may reflect
what?
3

A
  1. CO2 retention
  2. Accumulation of lactic acid
  3. Excess ketone bodies in patients with diabetes mellitus
56
Q

Respiratory system controls will attempt to raise the pH by increasing what? 2

A

respiratory rate and depth

57
Q

When arterial Po2 falls below __ mm Hg, it becomes the major stimulus for ______ (via the _______ chemoreceptors)

Changes in arterial pH resulting from __ _______ or metabolic factors act indirectly through the _______chemoreceptors

A

60
respiration
peripheral

CO2 retention
peripheral

58
Q

What is the most powerful respiratory stimulant?

Normally blood PO2 affects breathing only ______ by influencing peripheral chemoreceptor sensitivity to changes in ____.

A

Rising CO2 levels

indirectly
PCO2

59
Q

Hypothalamic controls act through the _________ to modify rate and depth of respiration.

Whats an example?

A

limbic system

breath holding that occurs in anger or gasping with pain (emotional response)

60
Q

A rise in body temp does what to respiratory rate?

A

increases it

61
Q

What are cortical controls?

example?

A

direct signals from the cerebral motor cortex that bypass medullary controls

Example: voluntary breath holding

62
Q

Pulmonary Irritant Reflexes
are located where?

What do they promote?

Receptors in the larger airways mediate what?

A

Receptors in the bronchioles respond to irritants

Promote reflexive constriction of air passages

Receptors in the larger airways mediate the cough and sneeze reflexes

63
Q

What is the Hering-Breuer Reflex?

A

Stretch receptors in the pleurae and airways are stimulated by lung inflation

64
Q

With the Hering-Breuer Reflex what kind of signals are sent to the medullary respiratory centers and what does this accomplish?

What kind of response is this?

A

Inhibitory signals to the medullary respiratory centers end inhalation and allow expiration to occur

Acts more as a protective response than a normal regulatory mechanism

65
Q

Exercise respiratory adjustments are geared to what? 2

What is hyperpnea?

_____, _____, and ____ remain surprisingly constant during exercise

A

the intensity and duration of exercise

Increase in ventilation (10 to 20 fold) in response to metabolic needs

Pco2, Po2, and pH

66
Q

Three neural factors cause increase in ventilation as exercise begins. What are they?

A
  1. Psychological stimuli
  2. Cortical motor activation
  3. Exictatory impulses
  4. Psychological stimuli—anticipation of exercise
  5. Simultaneous cortical motor activation of skeletal muscles and respiratory centers
  6. Exictatory impulses reaching respiratory centers from proprioceptors in moving muscles, tendons and joints
67
Q

Respiratory Adjustments: High Altitude

Quick travel to altitudes above 8000 feet may produce symptoms of acute mountain sickness (AMS). What are the symtpoms? 4

In severe cases? 2

A
  1. Headaches,
  2. shortness of breath,
  3. nausea, and
  4. dizziness

In severe cases, lethal cerebral and pulmonary edema

68
Q

Acclimatization: respiratory adjustments to altitude. What do these two adjustments result in?

A
  1. Chemoreceptors become more responsive to PCO2 when PO2 declines
  2. Substantial decline in PO2 directly stimulates peripheral chemoreceptors

Result: minute ventilation increases and stabilizes in a few days to 2–3 L/min higher than at sea level

69
Q

Acclimatization: hematopoietic adjustments to altitude. 3

A
  1. Decline in blood O2 stimulates the kidneys to accelerate production of EPO
  2. RBC numbers increase slowly to provide long-term compensation
  3. Increased BPG

Pulmonology (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions