Pulmonary system Flashcards
(133 cards)
1
Q
what regulates how fast the myosin head binds to the actin filament?
A
-different types of myosin heavy chains which relate to different muscle fiber types (MHC 1, 2a, 2x)
2
Q
more than ____ million alveoli provide the surface for gas exchange between lung tissue and blood
A
600
3
Q
there are ___ lobes in the left lung and ___ lobes in the right lung
A
2, 3
4
Q
cross sectional area ______ as we get to the respiratory zone of the lungs
A
increases
5
Q
what are the 4 characteristics of alveoli?
A
1) elastic (compliance)
2) thin walled (very important for gas exchange; disease can destroy alveolar sac (emphysema) or make membrane thicker to impede gas exchange)
3) surface for gas exchange
4) pores of Kohn (release surfactant)
6
Q
the interface between the capillaries and the alveoli are affected by exercise
true or false?
A
false
- most of the time
- if exercise is really intense, we can get edema (accumulation of ECF) - which becomes a barrier for gas exchange
7
Q
type 1 alveolar cell
A
- large surface area for gas exchange
- very thin barrier to gases
8
Q
type 2 alveolar cells
A
-secrete surfactant
(mixture of proteins, Ca++, phospholipids, which allows structures to inflate easily by reducing surface tension of water)
9
Q
when do we start producing surfactant?
A
- 7 months gestation
- premature babies can be short of surfactant and have to get it injected artificially (respiratory stress)
10
Q
the blood entering the lungs comes from which artery?
A
pulmonary artery from the heart
11
Q
as you age, elasticity and compliance ______
A
decrease
-elasticity helps move large volumes of air
12
Q
how do capillaries in the lungs respond in state of hypoxia (low O2)? (a.k.a. exercise)
A
they close
13
Q
Fick’s Law
A
the rate of transfer of a gas through a tissue is directly proportional to the partial pressure differential between the two sides, tissue surface area, a diffusion constant, and inversely proportional to the tissues thickness
14
Q
where is angiotensin converting enzyme produced?
A
in the lungs
15
Q
how much air makes up the tidal volume?
A
approx. 500 ml
- but 150 ml of this stays i the dead space, so only 250 ml of fresh air enters the lungs each breath
16
Q
why do the lungs instantly humidify the air entering with each breath?
A
to kill a lot of bacteria
17
Q
what is the partial pressure of oxygen on ambient air?
A
159 mmHg
-greater partial pressure facilitates diffusion
18
Q
the diameter of the bronchioles increases during exercise
true or false?
A
true
19
Q
inspiratory reserve volume
A
how much air we can breath in after a normal inhalation
20
Q
residual volume is about ___ L
A
1
21
Q
Forced vital capacity (FVC)
A
tells you how much air can be moved in and out of the lungs forcefully
-static lung volume
22
Q
FEV1
A
how much air can be exhaled in 1 second
-dynamic lung volume
23
Q
the ability to expel air from our lungs is mostly affected by _____ diseases, whereas the ability to fill up lungs with air is impacted by _____ diseases
A
obstructive, fibrotic
24
Q
breathing is governed by which area of the brain?
A
medulla and pons
25
the _____ part of the brain sets the pace/rhythm for breathing and the _____ commands these centres to be modified when you need to talk, cough, vomit, etc.
dorsal, pons
26
Boyle's Law
For a fixed amount of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional
-putting the same number of molecule's in a smaller container will increase pressure and vice versa
27
the diaphragm causes ____-____% of breathing at rest
75, 85
28
which are the expiratory intercostals? which are the inspiratory intercostals?
- internal (expiratory)
| - external (inspiratory)
29
the diaphragm lowers when we breath _____, which _______ the pressure inside the lungs
in, lowers
30
the diaphragm rises when we breath ____ which _____ the pressure inside the lungs
out, increases
31
dynamic ventilation depends upon which two things?
1) maximal forced vital capacity (FVC) of lungs
| 2) velocity of flow
32
velocity of flow of air out of and into the lungs is influenced by ______ and ______
resistance (airway), compliance (stiffness)
33
what does the ratio of FEV1/FVC tell us?
it indicates pulmonary airflow capacity
| -percentage of air exhaled (never equal to 1)
34
healthy people average about ___% of FVC in 1 second
85
35
______ disease result in significantly low FEV1, and ______ diseases result in normal (or above) FEV1 but the volume of air moved in lower
obstructive, restrictive
36
inspiratory capacity ______ during exercise (normally)
when would be a time where inspiratory capacity decreases with exercise?
increases
| someone with an obstructive pulmonary disease will have an inspiratory capacity that decreases with exercise
37
Maximum voluntary ventilation (MVV)
- evaluates ventilatory capacity with rapid and deep breathing for 15 seconds
- MVV = 15 sec volume x 4
- in healthy individuals is approx 25% greater than that seen during exercise (men = 140 L/min to 180 L/min; women = 80 L/min to 120 L/min
abnormal response is if you can only move 40% of normal range
38
how does respiratory muscle VO2 differ in older individuals, trained individuals, and untrained individuals?
- muscle VO2 increases with an increase in ventilation (exercise) quicker in older people (muscles have to work harder to breath, sooner)
- untrained individuals also need their respiratory muscles to work harder earlier to breath with increased ventilation
- trained individuals can do more work with less oxygen
39
a trained and an untrained person have very little difference in their FVC, FEV1, VE, and breathing rate at rest
true or false?
true
40
what are the two ways in which we can view ventilation?
1) volume of air moved into or out of total respiratory tract each minute
- minute ventilation (this ignores air that doesn't participate in gas exchange in the conducting zone)
2) air volume that ventilates only alveolar chambers each minute
- alveolar ventilation (only the air that we actually see crossing the membranes in the alveolus)
41
minute ventilation
volume of air breathed each minute (Ve)
Ve = tidal volume x breathing rate
-6 L/min
42
how much air is in the anatomical dead space?
150-200 ml
43
anatomical dead space increases as tidal volume increases
true or false?
true
44
because of the increase in anatomical dead space with an increasing tidal volume, breathing is less efficient
true or false?
false, despite the increase in the dead space, increases in TV result in more effective alveolar ventilation
45
which gives the most alveolar ventilation? shallow, normal, or deep breathing?
deep breathing gives the most, shallow breathing gives an alveolar ventilation of 0 because you're basically breathing the dead space in and out
46
what is the ventilation profusion ratio?
ratio of alveolar ventilation to pulmonary blood flow
```
V/Q = 0.8 L at rest (4.2 L air/ 5.9 L blood)
V/Q = 5 L during exercise (120 L air/ 25 L blood)
```
47
what is physiologic dead space?
- inadequate ventilation, under profusion of blood
- increases in something like emphysema, where capillaries/ alveoli are destroyed and the physiologic dead space increases
48
hyperventilation
- an increase in pulmonary ventilation that exceeds O2 needs of metabolism
- hyperventilation decreases PCO2 (decrease in H+ ions)
- leads to light headedness
- reduces the drive to breath because less protons are being made, so less carbonic acid is forming, resulting in less CO2 (which is the strongest stimulus to take a breath)
49
what is the strongest stimulus to take a breath?
CO2 (which is usually around 40 mmHg)
50
dyspnea
- subjective distress in breathing
| - during exercise, respiratory muscles may fatigue, resulting in shallow, ineffective breathing and increased dyspnea
51
how do breathing patterns differ in light, moderate, heavy, and max exercise?
- light exercise: there is an increase in the amplitude of breathing
- moderate exercise: deeper breathing, and the rate increases
- heavy exercise: increased amplitude and depth again
- max exercise (normal fit) - increased amplitude and depth of exercise approaching the limit of expiratory flow
- max exercise (fit): shifts breathing to use more inspiratory reserve volume which allows them to move more air per minute
52
partial pressure
partial pressure = % [gas] x total pressure of mixture
```
PO2 = (20.93 / 100) x (760 mmHg - 47 mmHg (effect of moisturizing air))
PO2 = 149 mmHg
```
PCO2 = 0.21 mmHg
53
is the partial pressure of oxygen greater in the trachea or in the alveoli?
greater in the trachea
54
is the partial pressure of CO2 greater in the trachea or in the alveoli?
alveoli
55
does nitrogen exert a greater partial pressure at the alveoli or the trachea?
alveoli
56
Henry's Law
at a constant temperature, the amount of a given gas dissolved in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid
-gas diffuses from high [ ] to low [ ]
57
what is the partial pressure in the alveoli?
100 mmHg
58
the diffusion rate into blood is dependant on which two things?
1) partial pressure differences
2) solubility of the gas in the fluid
- CO2 is 25x more soluble than O2
59
the partial pressure of ____ promotes diffusion into the blood stream (100 mmHg in the alveoli and 40 mmHg in the blood); whereas the partial pressure of ____ facilitates uptake back into the alveoli (40 mmHg in alveoli and 44 mmHg in the blood)
O2, CO2
60
what is oxygen's main transport method in the blood?
binding to Hb
61
which has a higher partial pressure of O2? arteriol blood or venous blood?
arteriol blood because O2 saturation is lower once the blood has gone through muscle tissue
62
why is the partial pressure of CO2 higher in venous blood than in arteriol blood?
because once blood gets to the tissue where O2 is taken in, CO2 is produced from the mitochondria through the krebs cycle
63
what are the dangers associated with partial pressures when diving deep down into the ocean?
- nitrogen does not dissolve unless under very high pressures
- pressure gets higher as we go deeper under water, nitrogen can dissolve into plasma which would impact electrical activity of the nervous system
- name of the movie was rapture of the deep
64
how does a normal individual differ from someone with an obstructive pulmonary disease in terms of O2-Hb saturation during exercise?
- during exercise, a healthy person can keep the O2 saturation close to 100% in the alveoli whereas someone with an obstructive disease can only keep it up to about 60 mmHg
- the greater partial pressure in a healthy individual promotes more O2 diffusion into blood,and thus more Hb saturation
- in other words, the response is much slower in obstructive diseases, contributing to the low FEV1/FVC ratio
65
how many methods of transport are there for O2 into the blood? CO2?
2 for O2, 3 for CO2
66
what are the two methods of transport for O2 into the blood?
1) dissolved into plasma
2) combined with Hb
most O2 binds to Hb
- only 15 mL is dissolved into the blood (this establishes the partial pressure gradient)
- this can regulate breathing in hypoxic conditions and determine loading of Hb
67
what is the key component to the functioning of Hb?
the iron group, which allows conformational changes in the shape of Hb, which lets O2 bind
68
the ____ state of Hb is when no oxygen is bound, and the _____ state is when oxygen is bound
tense, relaxed
69
as more O2 molecules bind to Hb, the binding rate _____
increases
70
how can we increase the number of Hb in our bodies?
- Hb is carried in RBCs, more RBCs = more Hb
- altitude training - less O2 in high altitudes = state of hypoxia (sensed by chemoreceptors), erythropoietin production stimulated by kidneys to produce more RBCs
- exogenous erythropoietin injection would also increase Hb [ ]
71
Hb [ ] in the blood can vary between individuals with training and genetics
true or false?
true
72
volume percent (vol%) refers to what?
the mL of oxygen extracted from a 100 mL sample of whole blood
73
what is the relationship between iron and O2 carrying capacity?
iron deficiency anemia reduces the O2 carrying capacity considerably
-iron is essential for carrying capacity of Hb
74
if there is 20 ml/dL of O2 on the arterial side of the capillaries, and 14 ml on the venous side, what is the vol%?
6 mL difference, so the vol% is 6 ml of oxygen per dL used by the tissue
75
what is the relationship between iron and heart rate? what does this mean?
after iron treatment, HR decreased, confirming that iron plays a large role in O2 offloading from Hb
76
does O2 have a stronger affinity for Mb or Hb?
much higher affinity for Mb, muscles store more oxygen
77
what does the flat portion of the O2 dissociation curve allow for?
allows for safety net in high altitude
78
what does the steep portion of the O2 dissociation curve allow for?
- rapid unloading in state of hypoxia
- exercise
- affinity for O2 to Hb is lower
79
when the partial pressure of O2 in the alveoli is at 100 mmHg, what is the Hb saturation in the blood?
- about 98%
| - supplemental oxygen intake will not have an impact
80
the partial pressure of an individual tissue is dependant on what?
the metabolism of that tissue (it's usually around 40 mmHg)
81
Is Hb affinity for O2 higher at muscle tissues or at the lungs?
higher at the lungs, it needs to be lower at muscle tissue to be able to offload oxygen
82
a decrease in pH leads to a/an _______ in O2 affinity for Hb
decrease
83
in presence of CO2, the O2 affinity for dissociation of Hb ______
decreases
84
describe the change in the OEC when pH lowers
-decreased pH makes the OEC shift to the right, decreasing affinity forO2
85
describe the change in the OEC when the pH increases
curve shifts to the left, increasing affinity fo rO2
86
there is an ______ in O2-Hb affinity with a decrease in temperature and vice versa
increase
87
increased DPG levels shifts the OEC to the ____
right
| -lowering affinity
88
high DPG levels are usually associated with what?
-increase in pH, increase in PCO2, and increase in temperature
89
there is an increase in DPG during increased rates of glycolysis
true or false?
true, RBCs can only produce energy through glycolytic means because they have no mitochondria
90
which has higher binding affinity to Hb? CO or O2?
CO has a much higher binding affinity
| -competitive inhibitor
91
polycythemia
- when there are more RBCs in blood than the normal range per 100 mL
- in high altitudes, you're always starving for O2 - kidneys recognize this and secrete erythropoietin to stimulate RBC growth
92
how do different altitudes affect the saturation of Hb in the blood?
higher altitudes have less availability of oxygen, which means there is a lower partial pressure
-if you begin with less O2, the Hb in the blood will be less saturated
93
what drives diffusion of oxygen from the atmosphere all the way down to the mitochondria?
the O2 transport cascade
| -partial pressure of O2 gets lower and lower as we shift from atmosphere to mitochondria, driving diffusion
94
what are the three mechanisms of CO2 transport in the blood?
1) in plasma
- 5% formed during metabolism transported via plasma
2) combined with proteins - including Hb
3) as plasma bicarbonate (70% of transport happens this way)
-CO2 + H2O ----- H2CO3 ----- H+ + HCO3-
in the lungs, this reaction is opposite and CO2 is released
95
when CO2 enters the RBC and combines with water, ______ is formed. When this molecule leaves the RBC, ____ comes into the cell in exchange in order to keep the negative charge
carbonic acid, Cl-
96
what are the three basic elements of respiratory control?
1) central controller - pons, medulla, and other parts
2) effectors - respiratory muscles
3) sensors - chemoreceptors, lung and other
97
what are the 6 main things that control breathing?
1) respiratory center (medulla)
2) chemical state of blood in medulla
3) core temperature
4) proprioceptors in joints and muscles
5) receptors in lung tissue
6) peripheral chemoreceptors
98
receptors in various tissies monitor ____, ____, ____ and ____ to control breathing rate
pH, PCO2, PO2, temperature
99
control of breathing - central controller - def
- ventral lateral medulla and pons
- intrinsic pacemaker neurons - controlled automatically, don't need an excitatory stimulus
- network for pattern generation
- active when we cough, vomit, yawn, etc.
100
control of breathing - efferent motor output - def
- cranial and spinal nerve innervation of upper airway (cranial nerve 9 and 12), bronchial smooth muscle and respiratory pump muscles
- SM relaxes during exercise
101
control of breathing - sensory - def
- medullary and carotid chemoreceptors - respond to partial pressure of O2 and CO2 (feedback to central controller)
- mechanoreceptors (in lungs) - monitors stretch of lungs
102
normal breathing is controlled by circuits in the ____ and _____
pons, medulla
this is called the pontomedullary circuit
103
_______ has pacemaker neurons linked to a pattern generator that controls breathing rate; ablation of this area or the rostural pons disrupts normal breathing
ventral lateral medulla
104
rhythm generation from the pontomedullary neuronal circuit is directed to the ____, _____, and _____ motor nerves
phrenic, intercostal, abdominal
105
which muscles are active during forced expiration? (exercise)
rectus and transverse abdominis, internal and external obliques, internal intercostals
106
inhalation is governed by the ______ (phrenic nerve)and ______ (intercostal nerve)
diaphragm, external intercostal
107
which additional muscles (other than diaphragm and external intercostals) control inspiration during exercise?
scalene muscles and sternocleidomastoids
108
whar do peripheral chemoreceptors detect?
-PO2, PCO2, and pH
109
what do medullary receptors detect?
- highly pH sensitive (due to changes in CO2)
| - responds to PCO2 strongly in steady state
110
mechanical sensory afferent feedback for breathing is provided by which nerve?
vagus
111
what does the vagus nerve do to control breathing?
- limits end-indpiratory lung volume
| - responds as a stimulus during lung deflation
112
respiratory muscle feedback is relayed by group ______ and grou ____ receptors
III mechanical, IV chemical
113
at the beginning of physical activity, the rate of breathing is controlled by _____ and if activity continues, breathing rate is controlled by _____
higher brain centers (and feedback from moving muscles), changes in blood chemistry (group III and IV receptors)
114
regulation of breathing during exercise - chemical control
- there is no single chemical mechanism responsible for hypernea during exercise
- partial pressures of CO2, O2, and blood chemistry is detected by peripheral chemoreceptors
115
regulation of breathing during exercise - neurological factors
- cortical influence (thalamus, limbic system ,motor cortex)
| - peripheral influence - feedback from proprioceptive inputs
116
temperature has a great influence on respiratory rate during exercise
true or false?
false, it has little influence
117
regulation of breathing during exercise - humoral factors
-chemical state of blood
118
what are the three ventilation phases during exercise and recovery?
phase 1) neurogenic stimuli from cerebral cortex and feedback from active limbs stimulate the medulla to abruptly increase ventilation
phase 2) after a brief plateau, ventilation rises exponentially to achieve a steady rate related to metabolic gas exchange demands
phase 3) fine tuning of steady rate ventilation through peripheral sensory feedback mechanism
119
hyperpnea - def.
increased depth and rate of breathing
120
after ceasing exercise, what is the abrupt decline in ventilation due to?
the removal of central command and input from receptors in active muscle
121
slower recovery phase from exercise is the result of which 2 gradual metabolic, chemical, and thermal adjustments?
1) gradual diminution of short term potentiation of respiratory center
2) reestablishment of body's normal metabolic, thermal, and chemical milieu
122
what can happen if the air that enters through the respiratory tract is not humidified/warmed?
- moisture is lost if the air is cold and dry
| - can contribute to dehydration, dry mouth, and irritation of respiratory passages
123
during what kind of exercise do we perform steady rate ventilation?
-during light to moderate exercise, ventilation increases lienarly with O2 consumption and CO2 production
124
during what kind of exercise do we perform non steady rate ventilation?
- minute ventilation sharply rises and the ventilatory equivalent rises as high as 35-40 L of air per liter of oxygen at the ventilatory threshold
- this is the same as the lactate threshold (1 mmol above normal [ ])
125
what is respiratory compensation?
another sharp increase in depth and rate of breathing that happens at the same time as the blood lactate accumulation point (4 mmol)
126
what are the 2 systems that regulate alkalosis/acidosis?
- kidneys
| - respiratory system
127
how can we use OBLA to predict performance success?
the speed at which the point of OBLA is reached is a good predictor of success
-can't exercise for much longer when we are above this threshold
128
the threshold for lactate appearance can result from which 5 things?
1) imbalance between rate of glycolysis and mitochondrial respiraiton
2) decreased redox potential (increased NADH + H+ relative to NAD)
3) lower blood oxygen content
4) lower blood flow to skeletal muscle
5) fiber type (utilize type IIx greater than type I)
129
OBLA can be used to predict performance but VO2 is a better tool, it is more consistent
true or false?
false, OBLA might be a better tool, as it is more consistent
130
what are the major variables that contribute to oxygen transport and use? (a.k.a aerobic performance)
- velocity of lactate threshold
- efficiency of movement
- cardiovascular dynamics (CO)
- amount of oxygen removed - dependant on Hb in blood
- capillary density, oxidative enzymes
131
what is said to be the "happy range" for our blood pH?
7.35
132
does ventilation limit aerobic power and endurance?
- healthy individuals over-breathe at higher levels of O2 consumption
- at max exercise, there usually is still a breathing reserve
- so ventilation in healthy individuals is not the limiting factor in exercise
133
maximal exercise is limited by ventilation
true or false?
false, there is a very small relationship among diverse lung volumes and capacities and exercise performance
-max exercise is not limited by ventilation
