CVP final Flashcards
1
Q
What sets the basic drive of ventilation, activates the muscles of respiration, and has descending neural traffic to the spinal cord?
A
respiratory neurons in the brain stem
2
Q
Pulmonary physiology includes the ventilation of alveoli coupled with perfusion of pulmonary capillaries and the exchange of _ and _ _?
A
oxygen, carbon dioxide
3
Q
Which heart chamber has 100% of its’ output to the lungs via the pulmonary vessels?
A
right ventricle
4
Q
Name the 3 centers for breathing in the respiratory control system.
A
- cerebral cortex & higher centers (like limbic system)
- mechanoreceptors
- chemoreceptors- monitor blood for mainly CO2 levels
5
Q
Name 2 respiratory centers located in the medulla oblongata. Name 2 in the pons. Which of the 4 sets the drive of the ventilation at about 12-14 breaths/minute? Respiratory centers affect the _ & _ of ventilation?
A
medulla oblongata: dorsal & ventral medullary group
pons: pneumotaxic & apneustic centers
- dorsal medullary group sets the drive of the ventilation
- rate & depth of ventilation
6
Q
The inspiratory muscles have what effect on the thoracic cage volume upon contraction? what about pressure? name some inspiratory muscles.
A
increase thoracic cage volume, decrease pressure;
inspiration: diaphragm, external intercostals, SCM, scaleni, levator costarum, ant & post superior serratus
7
Q
Expiratory muscles have what effect on the thoracic cage volume upon contraction? pressure? Name some expiratory muscles. Are expiratory muscles normally active or passive?
A
decrease thoracic cage volume, increase pressure;
expiration: abdominals, internal intercostals, transversus thoracis, pyramidalis, post inferior serratus
- expiratory muscles are typically passive because the lungs have a natural recoil tendency
8
Q
On inspiration, how much of the total body energy is used? Comment on how the diaphragm works upon inspiration.
A
3% used; the volume increases in the thoracic cage by dropping the floor out of the diaphragm
9
Q
Which expiratory muscle is a stabilizer of the lumbar spine, and when weak, can result in low back pain?
A
transversus abdominis
10
Q
What is it that keeps the lung inflated against the chest wall? What values does it vary between?
A
the pleural pressure-negative pressure between parietal & visceral pleura that keeps the lung inflated against the chest wall; varies between -5 and -7.5 cm H2O (inspiration to expiration)
11
Q
In alveolar pressure, it is _ during inspiration and _ during expiration? When they’re equal, the flow is 0. This happens 2x per cycle, which is at the beginning and end of normal expiration.
A
subatmospheric during inspiration, supra-atmospheric during expiration
12
Q
This pressure is a measure of the recoil tendency of the lung. It is the difference between alveolar pressure and pleural pressure. When does it peak?
A
transpulmonary pressure; peaks @ end of inspiration
13
Q
Name the phenomenon being described. At the onset of inspiration, the pleural pressure changes at a faster rate than lung volume does.
A
hysteresis “slinky dog”
14
Q
Is it easier to inflate an air-filled lung or a saline filled lung and why?
A
easier to inflate a saline filled lung because surface tension forces have been eliminated in the saline filled lung
15
Q
As pleural pressure becomes more negative, what happens to transpulmonary pressure?
A
it increases (since transpulmonary pressure is difference between alveolar pressure & pleural pressure)
16
Q
The compliance of a lung is its’ ability to expand and is figured by the change in lung volume divided by the change in _?
A
pleural pressure
17
Q
What effect does the thoracic cage have on the lung?
A
It reduces compliance by about 1/2 around functional residual capacity (at the end of a normal expiration). Compliance is greatly reduced at either high or low lung volumes
18
Q
In the work of breathing, what accounts for most of the work normally (roughly more than 90% of the work)?
A
compliance work (elastic work)
19
Q
Besides the compliance (elastic) work of breathing, what are some other forms of work involved?
A
tissue resistance work (viscosity of chest wall & lung); airway resistance work; energy required for ventilation is about 3-5% of total body energy
20
Q
During inspiration, comment on lung volume, size of airway caliber, and the amount of airway resistance.
A
increased LV, increased airway caliber, decreased airway resistance
21
Q
During expiration, comment on lung volume, size of airway caliber, and the amount of airway resistance.
A
decreased LV, decreased airway chamber, increased airway resistance
22
Q
This term for normal breathing is about 12-17 breaths/min, 500-600 ml/breath.
A
eupnea
23
Q
This term is an increase in pulmonary ventilation matching increased metabolic demand (same CO2 levels), such as during exercise.
A
hyperpnea
24
Q
This term is when an increased pulmonary ventilation exceeds metabolic demand (a decrease in CO2).
A
hyperventilation
25
This term is when a decreased pulmonary ventilation is less than metabolic demand (an increase in CO2).
hypoventilation (common during druggies taking depressants)
26
This term means an increased frequency of respiratory rate.
tachypnea
27
This term means an absence of breathing. Give an example.
apnea (sleep apnea)
28
This term means difficult or labored breathing.
dyspnea
29
This term is dyspnea when recumbent, and is relieved when one stands upright. aka "positional dyspnea". Which diseases exhibit it?
orthopnea; CHF, asthma, lung failure
30
Lungs have a natural tendency to _ as the surface tension forces are 2/3 and the elastic fibers are 1/3. However, the lungs are kept against the chest wall by negative pleural pressure "suction".
collapse
31
If the pleural space communicates w/the atmosphere (pleural pressure =atmospheric pressure), the lung will collapse. What are some causes of collapsed lungs?
puncture of the parietal pleura (sucking chest wound), erosion of visceral pleura (allows air in pleural cavity), and also if a major airway is blocked the air trapped distal to the block will be absorbed by the blood & that segment of the lung will collapse
32
This is a thin layer of mucoid fluid that provides lubrication, is a transudate (ISF + protein), and the total amount is only a few mL's. Excess is removed by _ from which areas?
pleural fluid; excess is removed by lymphatics from mediastinum, superior diaphragm surface, lateral surfaces of the parietal pleura, al helping to create negative pleural pressure "suction"
33
T/F: lymphatic drainage will decrease with increased venous pressure?
TRUE
34
What is a collection of large amounts of free fluid in the pleural space? aka edema of pleural cavity. What are some possible causes?
pleural effusion; causes-blockage of lymphatic drainage, cardiac failure (resulting in increased capillary filtration pressure), reduced plasma colloid osmotic pressure (starving people), and infection/inflammation of the pleural surfaces which break down capillary membranes
35
T/F: surfactant = pleural fluid?
False. surfactant is a detergent, not equivalent to pleural fluid.
36
This substance reduces tension forces by forming a monomolecular layer between aqueous fluid lining alveoli & air, preventing a water-air interface.
surfactant
37
Surfactant is produced by what cells? it is a complex mix composed of which substances?
produced by type II alveolar epithelial cells; complex mix of phospholipids, proteins, & ions
38
Briefly describe the role of surfactant using the Law of Laplace.
Without surfactant, smaller alveoli have increased collapse pressure & would tend to empty into larger alveoli, making the big bigger and the small smaller. Surfactant automatically offsets this physical tendency: as the alveolar size decreases, surfactant is concentrated, which decreases surface tension forces, offsetting the decreased radius size.
39
In the stabilization of alveolar size, the size of one alveoli is determined in part by surrounding alveoli. what is this term?
interdependence
40
This static lung volume is the amount of air moved in or out each breath (from peak-trough).
tidal volume (TV)-roughly 500 mL
41
This static lung volume is the maximum volume one can inspire above normal inspiration.
inspiratory reserve volume (IRV)- roughly 3,000 mL
42
This static lung volume is the maximum volume one can expire below normal expiration.
expiratory reserve volume (ERV)-roughly 1,100 mL
43
This static lung volume is the volume of air left in the lungs after maximum expiratory effort, and is the hardest to measure.
residual volume (RV)- roughly 1,200 mL
44
This static lung capacity is the volume of air left in the lungs after a normal expiration; the balance point of lung recoil & chest wall forces. a combination of ERV & RV.
functional residual capacity (FRC)- combo of ERV & RV.
| -FRC is typically about 93% in the alveoli
45
This static lung capacity is the maximum volume one can inspire during an inspiratory effort.
inspiratory capacity (IR)- combo of TV + IRV
46
This static lung capacity is the maximum volume one can exchange in a respiratory cycle.
vital capacity (VC)- a combo of IRV + TV + ERV (maximum to minimum)
47
This static lung capacity is the air in the lungs at full inflation?
total lung capacity (TLC)- a combo of IRV, TV, ERV, RV
48
Of the static lung volumes & capacities, which 3 cannot be determined by basic spirometry. What then are they determined by?
RV, FRC, TLC; determined by helium delution method
49
What is the helium delution method solving for? What is the formula used?
solving for FRC;
| FRC= (helium initial/helium final)-1, then multiplied by the initial volume in the jar
50
Restrictive lung conditons will reduce which lung volumes/capacities? What happens w/a restrictive lung condition? how does one happen?
VC, IRV, IC; an inability to expand the chest wall to get breath in; can happen w/subluxated ribs, black lung, or too tight of a corset
51
What is a determination of how fast you can get rid of the vital capacity from your lungs and is compromised w/obstructive conditions resulting in decreased air flow?
pulmonary flow rates
52
Name 4 pulmonary flow rates.
1. minute respiratory volume (RR * TV)
2. forced expiratory volumes (FEV's)- timed; FEV/VC
3. peak expiratory flow
4. maximum ventilatory volume
53
How many generations of branching are there considered in the lung? Name the chain from the trachea down to the 300 million alveoli.
20 generations of branching; trachea (2cm squared)--bronchi (first 11 generations of branching)-bronchioles, which lack cartilage (next 5 generations of branching)-respiratory bronchioles, where some gas exchange can take place (last 4 generations of braching)-alveolar ducts give rise to alveolar sacs which give rise to 300 million alveoli (SA 50-100 meters squared)
54
What is the area where gas exchange cannot occur, which includes most of the larger airways?
dead space
55
what is the anatomical dead space, and how much?
the airways; 150 mL (75 mL per lung)
56
What is the physiological dead space?
anatomical dead space & non-functional alveoli
57
At the end of a normal expiration most of the FRC is at the level of the _? What is the typical turnover of alveolar air?
alveoli; 6-7 breaths typical turnover of alveolar air
58
What is the typical rate of alveolar ventilation (air flowing to alveoli)? What is the typical pulmonary blood flow (cardiac output)? What is the ventilation/perfusion ratio typically?
4L/min; 5L/min; 4/5 = .8 ventilation/perfusion ratio
59
In terms of the autonomic efferent control of the airways, the SNS has beta receptors that cause dilatation. Does the direct/indirect effect predominate?
the direct effect is WEAK due to sparse innervation; the indirect effect predominates via circulating norepinephrine
60
What effect does parasympathetic muscarinic effects cause?
constriction
61
What are NANC nerves? Inhibitory ones release what, resulting in which effects? stimulatory NANC nerves cause what?
non-adrenergic, non-cholinergic nerves; inhibitory NANC nerves-release VIP & NO, causing bronchodilitation; stimulatory-bronchoconstriction, mucous secretion, vascular hyperpermeability, cough, vasodilation "neurogenic inflammation"
62
In terms of the autonomic Afferent nerves, what are the slow-adapting receptors associated with? Which receptors are senstive to mechanical stimulation, protons, low chloride solutions, histamine, cigarette smoke, ozone, serotonin, and PGF?
slow-adapting receptors: associated w/smooth muscle of proximal airways & stretch receptors (involved in reflex control of breathing & cough reflex); rapidly adapting receptors
63
In the autonomic control of the airways, these contain neuropeptides (like substance P, neurokinin A, calcitonin gene-related peptide), is selectively stimulated by capsaicin (red pepper), and is also activated by bradykinin, protons, hyperosmole solutions & cigarette smoke.
C-fibers (high density)
64
Locally, histamine binds preferentially to which receptors and facilitates constriction? Which prostaglandin series is for constriction?
H1 receptors; Prostaglandin F series
65
Environmental pollution, like smoke, dust, sulfur dioxide, and some acidic elements in smog will elicit what effect on the airways? What is this mediated by?
constriction; mediated by parasympathetic reflex & local constrictor responses
66
What is the normal level of bicarbonate (HCO3-)? Metabolic acidosis will stimulate what? What regulates bicarbonate?
24 mEq/L; metabolic acidosis (HCO3- < 24) stimulates ventilation; kidney regulates bicarbonate
67
What is the normal level of CO2? Respiratory acidosis will have what effect on ventilation? What regulates CO2?
40 mmHg; respiratory acidosis(CO2 > 40) will stimulate ventilation; Lung regulates Co2
68
An accumulation of CO2 leads to _ (a _ pH)?
acidosis; decreased pH
69
Compared to the aorta, how thick is the pulmonary artery? What about the RV compared to the LV? Which has a larger lumen; systemic or pulmonary arteries? why?
pulmonary artery wall 1/3 as thick as aorta; RV 1/3 as thick as LV; all pulmonary arteries have larger lumens, making them more compliant, operable under a lower presure, and can accomodate 2/3 of the stroke volume from the right ventricle
70
How do pulmonary veins compare to systemic veins?
pulmonary veins are shorter, but have a similar compliance compared to systemic veins
71
How much blood volume is found in the pulmonic system? _ stenosis can increase the pulmonary volume 100%? Shifts in blood volume have the greatest effect on which circulation system?
450 ml (9% of total blood volume); Mitral stenosis (going into LV) can increase the pulmonary volume 100%; shifts have a greater effect on pulmonary circulation by virtue of size
72
Where does venous drainage typically go to? What causes the LV output to be slightly higher (1%) than RV output?
Venous drainage is into azygous (1/2 the time) or pulmonary veins (1/2 the time); Drainage into pulmonary veins causes LV output to be slightly higher (1%) than RV output & also dumps some deoxygenated blood into oxygenated pulmonary venous blood
73
Which venous drainage system is known as the "short circuit" and why?
Drainage into the pulmonary veins is the short circuit; when this occurs, the blood doesn't pass through the pulmonary capillaries and never goes to the Right side of the heart
LA-(thru mitral valve) LV- Aorta- Bronchial arteries - lung - pulmonary veins- back to LA
74
What is very extensive, extending from all the supportive tissue of the lungs and courses to the hilum & mainly into the R lymphatic duct? It removes plasma filtrate, particulate matter absorbed from the alveoli, and escaped protein from the vascular system.
The pulmonary lymphatics
75
What helps to maintain negative interstitial pressure which pulls alveolar epithelium against the capillary endothelium, creating a "respiratory membrane"?
pulmonary lymphatics
76
What has higher pressure: systemic arteries or pulmonary arteries? What is the mean pulmonary arterial pressure? mean pulmonary capillary presure? mean pressure of major pulmonary veins & LA?
systemic arteries (120/80) have higher pressure than pulmonary arteries (25/8); mean pulmonary arterial pressure = 15 mmHg; mean pulmonary capillary pressure = 7 mmHg; major pulmonary veins & LA pressure = 2 mmHg
77
Pulmonary blood flow = _ _? What branch of the ANS typically increases blood flow throughout the body?
cardiac output; sympathetics typically increase blood flow
78
Within the lung, blood flow is distributed to _-ventilated areas?
well; low alveolar O2 causes release of a local vasoconstrictor which automatically redistributes blood to better ventilated areas
79
On pulmonary vascular smooth muscle, what effect will sympathetic stimulation have? What about parasympathetics? What is the major constrictor effect on pulmonary vascular smooth muscle?
symp: MILD vasoconstriction
parasymp: MILD vasodilation
* major constrictor effect on pulmonary vascular smooth muscle is low alveolar O2
80
Alpha receptors mediate vasoconstriction/vasodilation? What about beta receptors?
alpha-vasoconstriction
| beta-vasodilation
81
Under resting conditions blood is fully oxygenated by the time it has passed the _ of the pulmonary capillary?
first 1/3
82
T/F: If the velocity of blood is increased 3x, it will not have time to fully reoxygenate?
False. Even if velocity increases 3x, full oxygenation occurs
83
What is the normal transit time of blood through a pulmonary capillary? What about under high cardiac output?
.8 secs; about .3 secs under high cardiac output
84
In exercise, what is the limiting factor, that improves w/CHRONIC exercise?
stroke volume
85
Concerning hydrostatic pressure on regional pulmonary blood flow, what happens to the pressure as it goes from the apex to the base? Which zone is where there's no flow, but normally does not exist? Which zone is the continuous flow towards the base? Which zone is known as intermittent flow, typically found closer to the apex?
pressure is increased as gravity pulls it down (fluid being pulled to the bottom of the sponge); Zone 1=no flow; Zone 3=continuous; Zone 2=intermittent
86
Which zone in pulmonary blood flow has greater alveolar (air) pressure than capillary (fluid) pressure? Which zone is the entire lung in during intense exercise? In zone 2 during systole, comment on the pressure gradient.
zone 1; zone 3 (capillary P > alveolar P); during systole of zone 2, capillary P > alveolar P
87
Of the 4 Starling forces, which one is the only one that is increased in the pulmonary circulation compared to systemic? Which one is the same in both scenarios? How is excess fluid removed, and if it isn't, what happens?
interstitial colloid osmotic pressure is only one increased in pulmonary flow; plasma colloid osmotic pressure is the same; excess fluid is removed by lymphatics. If not, there is pulmonary edema, which will prevent gas exchange
88
T/F: As filtration forces rise, typically lymphatic drainage also rises?
TRUE
89
Whose basic gas law says that a bigger volume = less pressure at a constant temp? Who said the volume of a gas at the same temp & pressure will contain the same # of molecules? Who said as you heat a gas, either the volume or the pressure has to increase? What is the sum of the above gas laws?
Boyle's law; Avogadro's Law; Charles' Law; PV=nRT
90
PV = nRT. What does each symbol stand for?
```
PV=nRT
P=gas pressure
V=volume a gas occupies
n=# of moles of a gas
R=the gas constant
T=absolute temp in Kelvin (-273 degrees Celsius)
```
91
Who said that the bigger a gas, the less readily it can diffuse (rate of diffusion of a gas is inversely proportional to the square root of its molecular weight)? Explain Dalton's Law of partial pressures.
Graham's Law; Dalton's Law of Partial Pressures says that the pressure exerted by a mixture of gases is equal to the sum of each of the individual pressures exerted by each gas
92
What are the 3 most abundant elements of air?
Nitrogen: about 80%
oxygen: about 20%
argon: less than 1%
93
What is the pressure that is exerted by the water molecules to escape from the liquid to the air called? What is it due to? proportional to? At body temp, what is the vapor pressure of water?
vapor pressure of water; due to molecular motion; proportional to temp; at body temp (37 degrees C) the vapor P of H2O is 47 mmHg
94
Which air is much more humid: atmospheric air or alveolar air? Which one has more oxygen? nitrogen? CO2?
alveolar is more humid (more H2O vapor) & has more CO2; atmospheric air has more O2 & N2
95
Name the 6 determinants of diffusion across the respiratory membrane. Which ones are properties of the gas itself? Which one is the main determinant of diffusion?
1. temperature 2. solubility 3. cross-sectional area 4. square root of molecular weight (inversely proportional) 5. concentration gradient 6. distance (inversely proportional)
- solubility and square root of the molecular weight are the 2 gas properties
- *Solubility is the main determinant of diffusion
96
Which gas will readily diffuse across the respiratory membrane 20x more frequently than oxygen? why?
CO2 is 20x more diffusible than O2 because it's way more soluble than O2
97
What does O2 concentration in the alveoli average? What about CO2 concentration average in the alveoli?
O2- 104 mmHg
| CO2- 40 mmHg
98
The respiratory unit consists of about how many alveoli?How many layers thick is the respiratory membrane? How thick is the respiratory membrane in microns?
300 million alveoli; respiratory membrane consists of 2 layers (alveolar epithelium, capillary endothelium); it is .5-.6 microns thick
99
T/F: Under resting conditions, oxygen diffuses roughly 1/4 L/min.
True (21*11=230 ml, almost 250 ml which would be 1/4 L)
100
Comment on the concentrations of oxygen and CO2 as one expires air.
O2 falls from about 159 to 104 mmHg while CO2 rises from 0 to 40 mmHg
101
The first 100 ml of expired air is from where? The middle 150 ml of expired air is a mix of what? The last 250 ml of expired air is what type of air?
first 100 ml: dead space
middle 150 ml: mix of dead space & alveolar air
last 250 ml: alveolar air
102
Each normal breath turns over about how many milliliters of the total alveolar air volume? How many breaths does it take for the complete turnover of alveolar air? The slow turnover prevents what?
each normal breath (tidal volume) turns over 350/2150 ml's of the total alveolar air volume; approx. 6-7 breaths for complete alveolar air turnover; slow turnover prevents large changes in gas concentration in alveoli from breath-breath
103
What is the normal alveolar ventilation to pulmonary capillary perfusion ratio (V/P)? If the ratio decreases, it is usually due to a problem w/__ __? If the ratio increases, it is usually due to a problem w/__ __ of __?
4L/5L=.8; if ratio decreases, it's usually due to a problem w/decreased ventilation; if ratio increases, it is usually due to a problem w/decreased perfusion of lungs
104
What results in an increase in "physiologic shunt blood"-blood that is not oxygenated as it passes the lung?
a decreased V/P ratio as ventilation goes to 0
105
What results in an increase in the physiologic dead space-the area in the lungs where oxygenation is not taking place, including non-functioning alveoli?
an increased V/P ratio due to a decreased perfusion of the lungs from the RV
106
What is the maximum oxygen that can be absorbed from the lung & delivered to the tissue/minute? What is it limited by?
the VO2 max; it is limited by cardiac output, NOT pulmonary ventilation
107
What is the best measure of cardiovascular fitness?
VO2 max
108
During exercise training, VO2 max improves as _ increases while _ stays constant?
Stroke volume increases while heart rate stays constant
109
What is the VO2 max of a cardiac patient? a sedentary individual? An endurance athlete? What is the amount of O2 taken up on average @ rest?
1.5 L/min; 3.0 L/min; 6.0 L/min; .25L/min
110
In the transport of oxygen, the majority (97%) is found how? What about the other 3%? how many ml/dl of oxygen is carried from the lungs-tissues?
97% found bound to hemoglobin (increases carrying capacity greatly); 3% found dissolved; 5 ml/dl are carried from lungs-tissues
111
In the transport of CO2, the majority (70%) is found how? How much is dissolved? How much is bound to hemoglobin & other proteins? how many ml/dl of CO2 is carried from the tissues to the lungs?
70% found as bicarbonate ion HCO3-, a buffer for pH; 7% is dissolved; 23% is found bound to hemoglobin/other proteins; 4 ml/dl from tissues-lungs
112
Overall, blood is slightly _? What is the average pH of arterial blood (oxygenated)? What is the average pH of venous blood (deoxygenated)? In exercise, what can the venous blood pH drop to?
basic; 7.41 pH arterial blood; 7.37 pH venous blood; during exercise, venous blood can drop to 6.9
113
What is the ratio of CO2 output to O2 uptake?
4/5=.8 (the normal V/P ratio also)
114
What happens to oxygen out in the cells? If fats are mostly being metabolized for exercise, what is the maximum percentage of metabolic water generated from O2? If only carbs are used for energy, how much metabolic water is converted from O2?
80% is converted to CO2; 20% is converted to H2O; fats- 30% maximum for metabolic water converted from O2; carbs-possible to have no metabolic water generated from O2 as all O2 is converted to CO2
115
As the partial pressure of oxygen decreases, hemoglobin _ more oxygen? What is the saturation percentage of arterial (oxygenated) blood, and what is its' typical pressure? What about venous (deoxygenated) blood?
releases; arterial-97% saturation, 95 mmHg pressure; venous blood-70% saturation, 40 mmHg pressure
116
In the oxyen-hemoglobin complex, what would a saturation of 0% mean? What about a saturation of 100%? If the pressure drops below 40mmHg on the graph, a slight change in pressure of O2 would have a _ release of O2 from hemoglobin?
0%-all hemoglobin-binding sites are available; 100%-all binding sites on hemoglobin are taken; LARGE release of O2 from hemoglobin w/a slight change in pressure if the pressure drops below 40mmHg
117
In the oxygen-hemoglobin complex, a shift to the right would promote what? Where would a shift to the right be found: active tissues or lungs? what other effects happen with a shift to the right?
promote dissociation (facilitates unloading of O2 from hemoglobin); is found in active tissues; results in increase temperature, increase CO2 (& decreased pH), & increase in 2,3 diphosphoglycerate
118
Which enzyme in RBC catalyzes the reaction of H2O & CO2? what does carbonic acid dissociate into? As HCO3- leaves RBC, it is replaced by _, called a _ shift?
carbonic anhydrase; dissociates into H+ & HCO3-; replaced by chlorine (abundant in ECF), called a chloride shift
119
What competes w/oxygen for binding sites on hemoglobin?
carbon monoxide
120
The affinity of carbon monoxide for hemoglobin is _x higher than that of O2? Small partial pressures will saturate 97% of the hemoglobin & can decrease oxygen carrying capacity of hemoglobin by _%? .1% of CO can be _? What is CO poisoning rapidly treated with?
25x higher; 50%; lethal; CO poisoning rapidly treated w/95% O2 & 5% CO2
121
What are some physiologic roles of CO in the body?
signaling molecule in nervous system, a vasodilator, and has an important role in immune, respiratory, GI, kidney, & liver systems
122
The goal of ventilation is to keep arterial levels of _ & _ constant, a steady V/P ratio of .8. The nervous system adjusts the level of ventilation (RR & TV) to match _ of the lungs? By matching ventilation w/pulmonary blood flow (&therefore cardiac output), we also match ventilation w/overall _ _?
O2 & CO2; perfusion; metabolic demand
123
What sets the basic drive of ventilation? It is located where? The termination of which CN's? It is rhythmically self-excitatory, and the ramp signal excites muscles of _? What is a typical total cycle time of inspiration & passive expiration? this results in an average of how many breaths/min?
dorsal respiratory group (DRG); located primarily in the nucleus tractus solitarius in medulla; termination of glossopharyngeal & vagus nerves; muscles of inspiration; 5 secs for cycle time, resulting in 12 breaths/min
124
This area of the upper pons inhibits the duration of inspiration by turning off the DRG ramp signal after the start of inspiration for slower, deeper breaths.
pneumotaxic center
125
This structure located bilaterally in the ventral aspect of the medulla can stimulate both inspiratory & expiratory respiratory muscles during increased ventilatory drive.
ventral respiratory group of neurons
126
This structure, located in the lower pons, functions to prevent inhibition of DRG under some circumstances.
apneustic center
127
This person had an affair w/Freud's wife.
Breuer
128
This phenomenon is stimulated when stretch receptors (located in the airway walls) are at tidal volumes > 1500 ml (average TV is 500 ml) and inhibits the Dorsal Respiratory Group.
Herring-Breuer Inflation Reflex
129
These receptors located among the airway epithelium are stimulated w/sneezing, coughing, & possibly airway constriction.
irritant receptors
130
These receptors are located in the alveoli next to the pulmonary capillaries, and are stimulated when pulmonary capillaries are engorged or w/pulmonary edema, creating a feeling of dyspnea.
J receptors
131
The rise of CO2 is called?
hypercapnia
132
These are the primary stimuli for the chemical control of ventilation, but they are unable to cross the BBB, or other membranes in general.
hydrogen ions
133
Rises of CO2 in the CSF have an effect on stimulating ventilation (faster/slower) due to the lack of buffers in the CSF compared to the plasma?
faster
134
These receptors are responsible for 70-80% of the CO2 induced increase in ventilation.
central chemoreceptors (chemosensitive area of the respiratory center)
135
Central chemoreceptors (chemosensitive area of the respiratory center) only respond to _?
hypercapnia (increased CO2 levels)
136
These chemoreceptors respond both to hypoxia (low O2) and hypercapnia (increased CO2).
peripheral chemoreceptors
137
What are examples of peripheral chemoreceptors? What percent of CO2-induced increase in ventilation do they account for? What can they respond do?
aortic & carotid bodies; 20-30%; responsive to both hypoxia (SNS decreasing flow increases the sensitivity to hypoxia) and hypercapnia (2-3 mmHg rise in CO2)
138
T/F: CO2 cannot cross the BBB.
False. CO2 can cross the BBB, hydrogen ions cannot.
139
Hyperventilation has what effect on SV & CO? 2. coronary blood flow? 3. repolarization of heart? 4. oxyhemoglobin affinity? 5. cerebral blood flow? 6. skeletal muscle effect?
7. serum potassium?
1. decreased SV & CO 2. decreased coronary blood flow 3. impaired repol of heart 4. oxyhemoglobin affinity increased 5. decreased cerebral blood flow 6. skeletal muscle spasm & tetany 7. serum potassium decreased
140
What is the most prevalent cause of respiratory depression? Examples include morphine & sodium pentobarbital.
effect of anesthesia/narcotics
141
During exercise, what happens to the amount of corticospinal traffic?
increased corticospinal traffic which collaterally stimulates respiratory centers in the brainstem; also, fluctuations in O2 & CO2 levels in active muscle stimulate local chemoreceptors
142
Name 2 events that can stimulate rapid inspiration.
1. ice dumped over an unsuspecting person
| 2. blow in a baby's face
143
This is the extra O2 that is consumed post-exercise to replenish O2 stores & remove lactic acid? The body contains about how many liters of stored O2 that can be used for aerobic metabolism? In heavy exercise, stored O2 is gone how quickly? How high can O2 debt reach?
O2 debt; 2L of stored O2; gone in 2 mins; O2 debt can reach 11.5L
144
Which type of oxygen debt is responsible for 8L and is felt most prominently 40+ minutes post-exercise? A buildup of this causes extreme _?
lactic acid oxygen debt; extreme fatigue
145
When a baby is born, what is the most important adjustment (besides a Chiro adjustment of course!) they make? How much more difficult is it for babies to breathe that first breath than it is for us?
The first breath (often said to be the hardest breath we'll ever take); 20-40x harder for them
146
Name 3 structures that close after birth. What else disconnects? What happens to TPR? What happens to pulmonic resistance?
closure of foramen ovale (btwn. atria), closure of ductus arteriosis (at the great vessels), closure of ductus venosus (to bypass the liver); placenta disconnects; TPR increases; pulmonic resistance decreases (elimination of hypoxia)
147
As one ascends to a higher altitude, what happens to the barometric pressure? At 63,000 feet, the barometric pressure is 47 mmHg and the blood _?
barometric pressure decreases; blood boils
148
T/F: The fractional concentration of O2 in the air changes in proportion to the change in altitude.
False. the fractional concentration of O2 in air does NOT change w/altitude.
149
When ascending to great heights, an unacclimatized person suffers deterioration of nervous system function primarily due to _? Name some examples of effects this causes.
hypoxia; sleepiness, false sense of well being, impaired judgment, clumsiness, blunted pain perception, decreased visual acuity, tremors, twitching, seizures
150
In regards to acute mountain sickness, cerebral edema results from hypoxia & local _? pulmonary edema results from hypoxia and local _?
cerebral edema=hypoxia & local vasodilatation
| pulmonary edema=hypoxia & local vasoconstriction
151
Systemic tissues do what under hypoxia? What about the lungs?
systemic tissues-dilate under hypoxia
| lungs-constrict under hypoxia
152
After several days of acclimating to high altitudes, what is the result on ventilation?
ventilation can increase up to 5x as inhibition fades (low O2=ventilating at a greater rate)
153
Best acclimatized people are inhabitants of _ altitudes.
high
154
In regards to chronic mountain sickness, what are the effects on: 1. hermatocrit 2. pulmonary arterial BP 3. Right ventrice 4. TPR 5. ultimate results?
1. red cell mass (hermatocrit) increases
2. increased pulmonary arterial BP
3. enlarged RV
4. decreased TPR
5. congestive heart failure & death if person is not removed to lower altitude
155
In individuals who are becoming acclimated to higher altitudes, there is a great increase in pulmonary ventilation, along w/increases in RBC, lung diffusing capacity, tissue vascularity, capillary density, ability of tissues to use O2, and an increased synthesis of this which shifts the oxy-hemoglobin curve to the right. What does this give an advantage to?
2,3-DPG; advantage to tissues, disadvantage to lungs
156
As people descend beneath the sea, the pressure _ tremendously which can have a profound impact on the respiratory system. To keep the lungs from collapsing air must be supplied at high pressures which exposes pulmonary capillary blood to extremely high alveolar gas pressures, which is known as _? These high pressures can be _?
increases; hyperbarism; lethal
157
If at sea level, the atmospheric pressure is 1 torr and there is 1 liter of gas, how far down will the pressure double? When will it quadruple?
doubles at 33 feet, quadruples at 100 feet
158
The high partial pressure of nitrogen causes _ _ in about an hour of being submerged. What is this comparable to?
nitrogen narcosis; comparable to alcohol intoxication
159
Oxygen toxicity is preventable if one never exceeds the established maximum depth of a given breathing gas. For deep dives, generally past _ feet, divers use hypoxic blends containing a lower % of _ than atmospheric air.
180 feet; O2
160
Name the partial pressure that is usually not a problem as depth doesn't increase its alveolar partial pressure. If, however, the alveolar partial pressure of CO2
CO2; > 80 mm Hg, depression of respiratory centers, respiratory acidosis, lethargy, narcosis, anesthesia
161
When a person breaths air under high pressure for an extended period of time the amount of N2 in the body fluids increases at higher N2 levels equilibrates w/levels in the tissues. What is this known as?
decompression
162
T/F: N2 is NOT metabolized in the body.
True; it remains dissolved in the tissues until N2 pressure in the lungs decreases as the person ascends back to sea level
163
N2 dissolved in H2O equilibrates after how long? What about N2 dissolved in fat?
1 hour; several hours
164
Name the condition where the signs/symptoms include pain in the joints & muscles of the arms & legs 85-90% of the time, 5-10% of the time results in nervous system symptoms like dizziness, paralysis, & unconsciousness, and if pulmonary capillaries are blocked it's called "the chokes".
decompression sickness "Bends"
165
In decompression sickness, aka "Bends", nitrogen bubbles out of fluids after sudden decompression. The bubbles block many blood vessels; first the smaller blood vessels, then as bubbles coalesce _ vessels are blocked.
larger
166
A diver who has been breathing air and has been on the sea bottom at a depth of 190 feet for 60 minutes will take how long to decompress to prevent "Bends"?
3 hours
167
As an organ of metabolism, the _ ranks 2nd behind the liver?
lung
168
What is one advantage the lung has over the liver in terms of metabolism?
all blood passes through the lungs w/every complete cycle
ex: angiotensin I being converted to angiotensin II in the lung, and prostaglandins being inactivated in one pass through pulmonary circulation
169
The average adult inhales about _L air/day, including inert dust, particulate matter from plants & animals, gases from fossil fuel combustion, and infections agents like viruses & bacteria.
10,000 L air/day
170
What is associated w/an increased incidence of bacterial infections? What is associated w/an increase incidence of chronic bronchitis & emphysema? What is associated w/an increased incidence of hyperactive airways or interstitial pulmonary fluids?
chronic alcohol; cigarette smoke & air pollutants; occupational irritants like paint, solvents, & construction inhalation
171
_ _ protect airways & alveolar structures from inhaled foreign materials. These long hairs in the nose filter out larger particles? What is highly vascularized and acts as radiators to warm air & create air flow patterns in the nose?
Nasal passages; vibrissae; nasal turbinates
172
This mechanism is useful at clearing larger airways utilizing primarily the vagus nerve, but ineffective at clearing smaller airways due to the large total cross-sectional area of them which doesn't allow sufficient velocity to be created.
cough
173
This mechanism is associated w/the nasal passages, the irritation is sent over the trigeminal nerve to the medulla, and the uvula is depressed so large amounts of air pass rapidly through the nose to clear nasal passages.
sneeze
174
With sneeze & cough, the velocity of air escaping from the mouth & nose has been clocked at what speeds?
75-100 mph
175
Which mechanism clears the smaller airways by utilizing ciliated epithelium in the respiratory tract all the way down to the terminal bronchioles?
mucociliary elevator
176
In the lung, these are capable of phagocytising intraluminal particles. aka dust cells.
alveolar macrophages
177
This extra system for immune reaction in the lung has small proteins found in the blood that are synthesized in the liver to complement the ability of antibodies & phagocytic cells to clear pathogens from an organism? It is considered part of the immune system w/macrophages.
complement system
178
In terms of the immune reaction in the lung, name where these mucosal-associated antibodies are found: IgG, IgA, IgE.
IgG-lower respiratory tract
IgA-upper respiratory tract
IgE-predominantly a mucosal antibody
179
This portion of the immune system uses antibodies and accessory processes, such as Th2 activation, cytokine production, germinal center formation, isotype switching, affinity maturation, and memory cell generation to assist in immunity.
humoral immune system
