Cardiopulmonary III Flashcards
(110 cards)
1
Q
What is the natural state of the lungs?
A
Compressed
2
Q
What connects the Lungs to the Thoracic cavity?
A
Adhesive nature of the fluid between the Visceral and Parietal pleura
3
Q
What formula describes pressure changes in the lungs?
A
P1V1 = P2V2
4
Q
If Intra-alveolar volume increases, pressure…
A
Decreases
5
Q
If Intra-alveolar volume decreases, pressure…
A
Increases
6
Q
Normal breathing is…
Ventilator breathing is…
A
Negative pressure breathing
Positive pressure breathing
7
Q
At the point between exhale and inhale, the intrapleural pressure is…
A
Negative
*pulling back at compressed lungs
8
Q
When does intrapleural pressure become positive?
A
Force expiration
9
Q
What are the 3 factors that hinder air passage in breathing?
A
Airway resistance
Alveolar surface tension
Lung compliance
10
Q
What are the 2 receptors that affect bronchial radius?
A
Muscarinic (parasympathetic)
Beta-2 (sympathetic)
11
Q
What does alveolar tension counteract?
A
Collapsing Pressure
12
Q
Collapsing pressure is inversely proportional to…
Aka…
A
Alveolar Radius
Laplace’s Law
13
Q
What cells make surfactant in the lungs?
A
Type 2 Alveolar
14
Q
What is the major component of surfactant?
A
Dipalmitoylphosphatidylcholine (DPPC)
*62%, and other amphipathic phospholipids
15
Q
What is the primary function of surfactant?
A
Decrease surface tension
16
Q
Higher humidity climates require more or less surfactant?
A
More
17
Q
Large alveoli have _____ collapsing pressures while small alveoli have _____ collapsing pressures.
A
Low
High
18
Q
What is the collapse of alveoli called?
A
Atelectasis
19
Q
The opposite of stiffness is…
A
Compliance
20
Q
Compliance =
A
Volume/Pressure
21
Q
What antibody does allergen bind in the lung?
What does binding induce?
A
IgE
Mast cells release Histamine and Leukotrienes
22
Q
What do Histamine and Leukotrienes cause?
What timeframe?
A
Contraction smooth muscles in bronchi
Occurs within 1 hour allergen exposure (early phase)
23
Q
What type of inflammatory cells are preferentially drawn into the lungs in response to an allergic reaction?
What timeframe?
A
Eosinophils
4-5 hrs Late phase
24
Q
T/F
There is no genetic component to making IgE antibody associated with asthma.
A
False
probably genetic
*can be allergic or non-specific like cold or exercise
25
The 4 physiological/pathological characteristics of asthma?
Increased responsiveness of trachea/bronchi
Bronchoconstriction
Inflammation
Thick mucus
26
What are the 2 most common obstructive lung diseases?
COPD (chronic obstructive pulmonary disease)
| Asthma
27
What are 2 types of COPD?
Emphysema
| Chronic bronchitis
28
What defines an obstructive lung disease?
Difficulty fully exhaling
| air lingers in lungs after full expiration
29
What defines a restrictive lung disease?
Cannot fill lungs
*often because of stiffness
30
What are some conditions causing restrictive lung disease?
Obesity
ALS
Muscular dystrophy
31
What is another way of assessing pulmonary function besides measuring respiratory volumes and capacities using spirometry?
FEV
| Forced Expiratory Volume
32
What is the normal FEV (1.0)?
75-85% vital capacity exhaled in 1.0 seconds
33
FEV (1.0) below 75% suggests?
| above 85% suggests?
Obstructive (difficulty exhaling)
Restrictive (no air left because difficulty filling lungs)
34
100% FEV =
FVC - forced vital capacity
35
By how much does Hemoglobin increase carrying capacity of blood?
70x
36
How much Oxygen is dissolved in plasma?
| How much bound to Hb?
1. 5%
| 98. 5%
37
Structure of Hemoglobin.
2 Alpha
2 Beta
4 Heme subunits
38
What is the saturation of Arterial blood?
| What is the saturation of Venous blood?
98-100%
| 75%
39
What accounts for the sigmoid shape of the Oxygen-Hemoglobin binding curve?
How does this manifest physiologically?
Positive cooperativity
Easier to pick up Oxygen at lungs and drop off at tissues
40
Name 5 blood factors that influence Hemoglobin saturation.
```
Temperature
pH
2,3 BPG
2,3 DPG
CO2
```
41
What RBC binding factor affecting Hemoglobin saturation with Oxygen is made by RBC's as the break down glucose?
2,3 BPG
| also 2,3 DPG
42
What are the 3 most important factor that influence Hemoglobin saturation?
pH
Temperature
CO2
43
What shifts the Hemoglobin binding curve to the RIGHT?
(decreases affinity for Oxygen)
What is this known as?
Increase in CO2
decrease in pH (more acidic)
Bohr Effect
(shifts to the right increase unloading Oxygen in tissues)
44
How does exercise create the Bohr Effect?
tissues produce more CO2
decreases pH
Unloads Oxygen at tissues
45
What does an increase of temperature do to the Hemoglobin binding curve?
Shifts to the right
| gives up Oxygen more easily
46
What binds to the Beta chains of deoxyhemoglobin and decreases the affinity of hemoglobin for Oxygen?
2,3 DPG
47
What blood factor is increased in those that live at high altitude?
2,3 DPG
*facilitates Oxygen unloading at the tissues
48
Shifts to the right ____ affinity of hemoglobin for Oxygen.
| Shifts to the left _____ affinity of hemoglobin for Oxygen.
Decrease
| Increase
49
What is the affinity Hemoglobin has for Carbon Monoxide compared to Oxygen?
200x
50
Carbon monoxide binding shifts the curve to the _____, then _____.
Left (increases affinity for remainder oxygen)
| flatlines
51
A decrease in arterial oxygen is...
| A decrease in oxygen delivery to tissues is...
Hypoxemia
| Hypoxia
52
Three things that cause hypoxia:
Decrease Cardiac Output
Decreased Oxygen binding capacity Hb
Decreased arterial Oxygen
53
What is lack of Hemoglobin (due to RBC or Hb deficiency) called?
Anemic hypoxia
54
What is blockage of blood flow leading to bad delivery of oxygen called?
Ischemic (or stagnant) hypoxia
55
Lack of Oxygen because cell can't use:
Histotoxic hypoxia
| poisons
56
Lack of Oxygen due to... lack of oxygen (pulmonary disease, altitude, etc).
Hypoxemic hypoxia
57
What are the 3 ways Carbon Dioxide is carried in the blood?
Dissolved (small amount)
Carbaninohemoglobin (also small amount)
HCO3- (major form)
58
How is CO2, in the form of HCO3-, carried through the blood?
| Where does rxn take place?
in RBC's
RBC's
59
What enzyme converts CO2 + H2O > H2CO3?
| bicarbonate
Carbonic Anhydrase
| in erythrocyte
60
H2CO3 > H+ + HCO3-
| What prevents this from lowering blood pH?
H+ is bound to hemoglobin
61
What does the Chloride shift do at the tissues?
Binds RBC and kicks HCO3- into plasma
| this maintains osmotic equilibrium
62
What does the Chloride shift do at the lung?
Chloride leaves RBC for HCO3- and is converted back to CO2.
63
What matches to achieve the ideal exchange of Oxygen and Carbon dioxide?
Ventilation - Perfusion Ratio
| V/Q
64
What is the V/Q ratio if the frequency, tidal volume, and cardiac output are normal?
0. 8
| 4. 2 L/min ventilation / 5.5 L/min blood flow
65
What could drive the V/Q ratio to zero?
Shunt
| blockage of airflow in lungs
66
What are the normal pressures of Oxygen and Carbon Dioxide in the blood?
100 mm Hg Oxygen
| 40 mm Hg Carbon dioxide
67
What could drive the V/Q ratio to infinity?
Dead Space
*no circulatory perfusion by blockage
68
What are the 3 groups of neurons in the brainstem that control breathing?
Where are they in brainstem?
Medullary respiratory center
Apneustic center
Pneumotaxic center
1st in Medulla, latter 2 in Pons
69
What group of nerves is responsible for spontaneous breathing and is perhaps the most important set of nerves we have?
Where is it?
DRG - Dorsal Respiratory Group
Medulla
70
What does the DRG (Dorsal Respiratory Group) innervate?
| What does the VRG (Ventral Respiratory Group) innervate?
Inspiratory muscles
Expiratory muscles
*make up Medullary Respiratory Center
71
What 2 cranial nerves are the DRG inputs?
What info do they input?
X Vagus - peripheral chemoreceptors and mechanoreceptors
IX Glossopharyngeal - peripheral chemoreceptors
72
What makes is the output of the DRG?
| What does it innervate?
Phrenic nerve
Diaphragm
External Intercostals
73
When is the VRG active?
Exercise
*when passive expiration isn't enough
74
How much time does the DRG spend in the Active and Inactive states in normal breathing?
2 seconds active (inspiration)
| 3 seconds inactive (expiration)
75
What type of inspiration does the Apneustic Center stimulate?
Ispiratory gasps (apneusis)
brief exhalations
76
How does the Apneustic Center affect the Medulla?
Prolongs action potential in Phrenic nerve and contraction of diaphragm
77
What neuronal center limits the size of the Tidal Volume?
| Where is it located?
Pneumotaxic Center
| Upper Pons
78
What neuronal center limits action potentials of the Phrenic nerve?
Pneumotaxic Center
79
Hyperventilation causes blood pH to...
Increase
80
Where are the Central and Peripheral Chemoreceptors located?
Central - bilateral ventrolateral Medulla
Peripheral - aortic arch/carotid arteries
81
What stimuli increase the breathing rate?
Decrease pH
Increase CO2
*Medulla
82
A decrease in pH and/or increase in CO2 will stimulate what type of chemoreceptor?
Central or Peripheral
83
An decrease of Oxygen below 60 mm Hb will stimulate what kind of chemoreceptor?
Peripheral
84
What is the most potent and closely controlled chemical influencing respiration?
What is its normal range?
CO2
40 mm Hg
*controlled to within +/-3 mmHg
85
What is the main mechanism of control over the effects of CO2?
Central chemoreceptors
86
What is the central Chemoreceptor in the Medulla particularly sensitive to?
Why?
pH CSF
CO2 crosses BBB much easier than H+
must breath faster
*H+ acts directly on Medullary receptors
87
How does CO2 increase H+ in the CSF?
CO2 + H2O > H+ and HCO3-
*via carbonic anhydrase
88
What type of receptors are sensitive to arterial Oxygen?
Peripheral
*CO2 has much greater effects on these receptors
89
At what point does dearth of Oxygen become a major stimulus to peripheral chemoreceptors?
60 mmHg or below
90
What type of chemoreceptors are most important in regulating CO2?
Central
91
What is the term for the result chemoreceptor adaptation in which Oxygen takes over as the primary chemical regulator?
(often due to pulmonary disease)
Hypoxic Drive
92
Why is gas mixture only slightly enriched with Oxygen in people with Hypoxic Drive?
If it's too high (above 60 mmHg) will slow breathing.
93
Name 3 non-chemical receptors that also input to the brainstem and regulate breathing?
Lung stretch receptors
Irritant receptors
Joint and muscle receptors
94
What is the Herring-Breuer reflex?
Lung stretch reflex
*prevents over-expansion
95
Where are irritant receptors located?
| What nerve innervates?
Between epithelial cells lining airways
Vagus
*restricts and increases breathing rate
96
What 2 components lead to increased breathing before exercise?
Anticipation (Pavlovian)
| Stretching
97
For this class, Acids are...
| Bases are...
Proton donors
| Proton acceptors
98
Henderson Hasselbach:
pH = pKa + log [HCO3-] / [CO2]
*at 20:1 pH = 7.4
99
What is the normal range of pH in ECF?
7.35-7.45
100
What are the 3 lines of defense against increase in H+?
Buffers
Lungs
Kidneys
101
What are the 3 major buffers in the body?
Bicarbonate (and protonated carbonic acid)
Phosphate
Protein
102
What parts of a protein respond to Acidosis?
| Alkalosis?
acidosis: Amine accepts proton
alkalosis: carboxyl releases proton
103
What effect does hypoventilation have on pH?
decreases pH
104
What effect does Hyperventilation have on pH?
increase pH
105
What are the 3 ways kidneys regulate pH and where does this regulation occur?
Secretes H+ (distal convoluted tubule)
Reabsorbs HCO3- (prox. convoluted tubule)
Synthesizes HCO3- (prox. convoluted tubule)
106
What is Respiratory Acidosis caused by?
| What are its effects in the kidney?
Emphysema (anything can't breath)
Increases secretion of H+
107
What causes Respiratory Alkalosis?
| Effects in kidney?
Altitude, anxiety
Decrease secretion H+
108
What causes Metabolic Acidosis?
| Effect on HCO3-?
Production of H+ (ketoacidosis, etc)
Decreases HCO3-
*Kidneys secrete H+
109
What causes Metabolic Alkalosis?
| Effect on HCO3-?
Severe emesis
| Increase HCO3-
110
What are 2 strategies of dilating airways for asthma?
Beta-2 agonists (mimic norepinepherine)
| Muscarinic blocks
