Breathing (Topics 1-10) Flashcards

(347 cards)

1
Q

How many cells do we end up with?

A

10^14 cells with different structure and functions

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

What is Homeostasis?

A

the ability of a cell or organism to regulate its internal conditions

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

What are the 7 factors that make up homeostasis?

A
  1. Nutrient molc con
  2. O2 and CO2 con
  3. Waste products con
  4. pH acidity
  5. Water, salt & electrolytes con
  6. Blood plasma volume and pressure
  7. Temperature
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the 3 steps in coordinating a response to different organs?

A
  1. Sensory system
  2. Relay station
  3. Response system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the 3 different kinds of feedback systems?

A
  1. Positive
  2. Negative
  3. Feedforward
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a positive feedback system + example?

A
  • getting stimulus further from homeostasis
    ie. Pregnancy, blood clotting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a negative feedback system + example?

A
  • getting stimulus back to homeostasis
    ie. Temperature controls, Breathing patterns
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

True or False
Feedforward relates to the anticipatory response, if true what is an example?

A

True, like CNS

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

What are the 3 keys parts to a negative feedback?

A

Set variable point

  1. Sensor
  2. Integrator
  3. Effector (adjusts and gets back to set variable point reliving the stimulus)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

True or False
Set points are maintained over small ranges?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

True or False
Set points can be reset (up or down)?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the ideal temperature for the cell?

A

37 degrees

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

How many breaths does the average person take per minutes?

A

12

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

What is the ideal pH level?

A

7.4

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

Which type of feedback system is more common?

A

Negative

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

Are negative feedback systems constant?

A

Yes

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

What is dis-regulation?

A

when we cannot get back to our set point

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

What is the main purpose of the respiratory system?

A

to get O2 for use by the bodies cell and to eliminate CO2 produced from the cells

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

What are the 2 processes of respiration?

A
  1. Internal
  2. External
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the 4 steps in External respiration?

A
  1. Ventilation
  2. O2 and CO2 exchange between air in alveoli to blood
  3. Blood Transport
  4. O2 and CO2 exchange between blood and tissues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

True or False
Oxygen and Carbon dioxide are doing the 4 steps of ventilation in opposite orders

A

True

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

What are the concentrations of O2 and CO2 when we breath air IN?

A

O2: 21%
CO2: 0.03%

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

What are the concentrations of O2 and CO2 when we breath air OUT?

A

O2: approx 16%, lower than 21%
CO2: 4-5%, higher than 0.03%

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

What do veins carry?

A

deoxygenated blood, carbon dioxide rich blood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What do arteries carry?
oxygenated blood, carbon dioxide poor blood
26
What are the 4 non-respiratory functions of the respiratory system?
1. Water 2. Heat loss 3. Enhances venous return 4. Speech 5. Singing
27
How does the respiratory system enhance veinous return?
due to the fluctuations of pressure in the chest wall, where the heart is enclosed
28
What are the pathways of oxygen going from the atmosphere into the lungs?
- nasal passage / oral passage - larynx goes down - trachea - right and left bronchi - right and left bronchioles - terminal bronchioles - alveolar sacs - alveolus
29
What is the area of conduction zone. Start and End
Trachea to Terminal bronchioles
30
How many times does the bronchus split through bronchioles to alveoli?
23 times
31
Is there any gas exchange in the conducting zone?
No
32
Where does gas exchange mainly occur?
Alveoli, alveolus
33
True or False The pressure at the alveolus level is very low due to the huge amount of cross-sectional area
True, for us to have a gas exchange
34
The bronchi all the way to the terminal bronchioles and the alveoli are covered in cilia, why?
to help protect against foreign things, aka coughing will occur to get particles removed
35
What are the 2 reason we secrete mucous in the lungs?
1. To keep moist and lubricated 2. It can represent inflammatory response
36
What dictates as the respiratory zone?
alveolus and alveolar sacs
37
Why are the small airways in the respiratory system covered in smooth muscle? aka terminal bronchioles
this can change the diameter of the tube
38
Where are the Pores of Kohn?
within the alveolar sacs
39
What are the 2 things the Pores of Kohn allow for?
1. Allows for alveolar communication 2. Ensuring each alveolus is properly inflated, “pressure needs to be the same”
40
What does Surfactant do?
regulates breathing pressures, and keeps the alveolus from collapsing
41
True or False Capillaries completely engulf each alveolus
True
42
How many alveolus are there?
approx 3 million
43
How many capillaries are there?
6 million
44
What is dictated as the thoracic cavity?
bottom of the lungs to the top of the collarbone
45
What is the thoracic cavity?
air-tight sealed space, shared with heart and blood vessels
46
What are the 3 areas that large quantities of elastic connective tissue help with?
1. Maintain the size of our chest 2. The volume of air in the lungs 3. Ease of breathing
47
True or False The elastic connective tissue allows us not to use our muscles to breathe out
True, due to the elastic properties of the lung
48
Why do the bronchioles have smooth muscle?
for constriction and dilation controlled by the autonomic nervous system
49
What do puffers do?
bronchial-dilator: relax smooth muscle to open up the airways targets the smaller areas of the bronchioles
50
What do the walls of Alveoli consist of?
a single layer of flattened Type 1 alveolar cell
51
What do Type 2 alveolar cells do?
makes pulmonary surfactant
52
Where are type 2 alveolar cells located?
in the lumen of the alveolus
53
After how many weeks approximately will infants create surfactant on their own?
34-35 weeks
54
What does surfactant do?
decrease the surface tension on the Type 1 walls of the alveolus
55
What do Alveolar macrophages do?
Guard lumen - the individual alveolus
56
What do Pores of Khon do?
allow for airflow between adjacent alveoli aka collateral ventilation, communication between cells
57
What is the approximate diameter of an alveolus?
300 micrometers
58
The distance between the alveolar wall and the pulmonary capillary is what?
0.5 micrometres
59
What is the distance between the alveolar wall and the pulmonary capillary called?
interstitial space
60
When would the interstitial space be larger than normal or compromised?
pulmonary edema
61
What is high-altitude pulmonary edema?
the high altitude pressure will cause a leakage of the capillary network into the interstitial space causing it to expand
62
True or False Cystic fibrous and Pulmonary embolism leads to fluid accumulation in the interstitial space
True
63
What is the most important thing about the chest wall other than protection?
It has muscles involved that generate pressure that causes airflow
64
People with lung disease will overuse which muscle?
sternocleidomastoid
65
What are the 5 key muscles for INSPIRATION?
- diaphragm (MAIN ONE) - sternocleidomastoid - scalenes - external intercostal (lines go towards sternum) - parasternal intercostals
66
What are the 5 key muscles for EXPIRATION?
- Internal intercostals (facing away from the sternum) - external abdominal oblique - internal abdominal oblique - transversus abdominis - rectus abdominis
67
True or False The muscles for inspiration are the same as the muscles we use to hold our breath in?
True
68
If we need to cough, exercise, sing, or breathe out anything faster than the natural resting lung rate then we use which muscles?
expiration muscles
69
The diagram accounts for what percent of the enlargement of the thoracic cavity during quiet respiration?
75%, due to the contraction and flattening of the diaphragm
70
True or False By increasing the volume we can decrease the pressure
True, Boyle's law
71
What is the pleura?
the double-walled, closed sac that separates each lung from the thoracic walls/chest wall
72
The pleura attached to the outer surface of the lung is called what? *Attached to the actual organ
visceral pleura
73
The pleura attached to the chest wall (the thoracic wall and the diaphragm) is called what?
Parietal pleura
74
What are the 3 layers to the pleural sac?
1. Visceral pleura 2. Partial pleura 3. Intrapleural fluid
75
When the pleural space expands what is the sign of the pressure inside, positive or negative?
negative
76
What are the 4 different pressures we need to take into consideration?
1. Atmospheric (barometric) pressure 2. Alveolar pressure 3. Pleural pressure 4. Transpulmonary pressure
77
What is Atmospheric pressure?
- pressure pushing down on us from in the room - 760mmHg
78
What is Alveolar pressure?
pressure inside the alveoli
79
What is Pleural pressure?
pressure inside the pleural space
80
What is Transpulmonary pressure?
- equals the difference between the alveolar and the pleural pressure - pressure across the visceral pleura
81
Will the atmospheric pressure go up or down when climbing a mountain?
higher up lower pressure
82
Will the atmospheric pressure go up or down when getting to sea level?
closer to sea level the higher the pressure
83
What is the intrathoracic pressure representing?
- pleural pressure - pressure in the thoracic cavity
84
what is another word for recoil pressure?
transpulmonary
85
If the atmospheric and alveolar pressure are equal, is there airflow?
No
86
How we move air in and out is dependent on what?
alveolar pressure
87
What will the alveolar pressure need to do to inspire and get air into our lungs?
alveolar pressure must become lower than the atmospheric pressure to create a gradient, so air can go from high-pressure to low-pressure
88
What will the alveolar pressure need to do to expire and get air out of the lungs?
alveolar pressure must be higher than the atmospheric pressure
89
What is the unit of pressure in the lungs?
cm per water
90
What leads to a collapsed lung?
when the pleural pressure gets compromised
91
What does transmural refer to?
pressure across something
92
What are the 2 kinds of transmural pressures and what are they going across?
1. Transpulmonary pressure - difference across lung wall 2. Transwall pressure - difference across the chest wall
93
True or False The transpulmonary pressure = alveolar pressure - pleural pressure
true
94
What are the 3 factors that will determine pressures in regards to air?
1. Volume - size 2. Temperature *temp can change volume 3. Number of molecules - how many molecules are there
95
What does negative flow mean in regards to where air is moving?
air is moving into the lung
96
As flow is negative what is happening to the volume?
increasing the volume of the lung
97
What is pneumothorax
- abnormal entering or air into the pleural space - no pressure gradient in place to opposes the negative pleural pressure keeping it in place forcing lung to collapse
98
Compliance refers to what?
how much effort is required to stretch the lungs - stiffness of the lung
99
True or False To generate flow into the lungs we need to decrease the alveolar pressure
True
100
Flow is measured in what unit?
Liters per second
101
Is it possible to have 0 flow? if so when would that occur?
yes, between inspiration and expiration
102
What causes us to get winded?
- when we get hit in the gut that can temporality paralyze our phrenic nerve - the phrenic nerve is the one that send the signals to our diaphragm to keep our breathing - which is why we find it hard to breath
103
What is the pleural pressure at the end of an expiration before an inspiration?
-4
104
True or False As we expand the lung in inspiration the recoil pressure will increase due to the elastic force
True
105
How could we un-stretch our lungs “right now?”
breathing everything out, where the pleural pressure may become positive
106
Is it possible for us to fully deflate your lungs?
no
107
What are the 2 common types of pneumothorax?
a) Traumatic pneumothorax - puncture wound in the chest wall - complete puncture ie. car accident (b) Spontaneous pneumothorax - a hole in the lung ie. genetic
108
Inspiratory muscles generate the force required to change what?
volume to generate airflow
109
The expiratory muscles are required to increase which pressures to empty the lungs?
intrapleural and alveolar pressures
110
What is respiratory compliance?
How much air do we move for a given level of respiratory effort or pressure change?
111
What does it mean if we have a highly compliant lung?
we do not need much effort to move lots of air
112
What does it mean if we have a poorly compliant lung?
we need a lot of effort to move a little air
113
What is COPD?
Chronic obstructive pulmonary disease - high lung compliance
114
Why would we breathe at the linear area of the normal compliance curve? (sigmoid)
there is a specific level of inflation where it is the most efficient and easiest to breath
115
What is fibrosis? (case of decreased compliance)
where the lung is stiff and scared
116
Increased compliance is equal to what kind of stiffness?
decreased stiffness
117
Decreased compliance is equal to what kind of stiffness?
Increased stiffness
118
Why wouldn’t everyone want highly compliant lungs?
because it would make breathing out harder, and we lose the elasticity and recoil pressure
119
Why do we not need expiratory muscles to expire air?
because of the recoil pressure, aka transpulmonary pressure
120
True or False For highly compliant lungs (emphysema) they need to recruit expiratory muscles to breath out
True
121
What is the normal compliance of a lung in cmH20?
2.0 L
122
Why do we breath where we breath?
it optimizes the work that we do
123
What are the 2 factors affecting a lung’s elastic recoil for lung and total respiratory compliance? (aka factors of compliance)
1. Highly elastic connective tissue in the lungs - any diseases that we mentioned will affect the connective tissue (stiff or floppy) 2. Surface tension of the alveoli - ability to balance out the alveolar pressure from each alveolus throughout the lung (premature babies do not secret surfactant so they cannot regulate the tension and pressure in the alveoli)
124
What is pulmonary surfactant?
- complex mixture of lipids and proteins - made by type 2 alveolar cells - spreads out between water molecules in the fluid lining of the alveoli and lowers alveolar surface tension
125
What are the 2 benefits of the pulmonary surfactant?
1. Reduces work of the lungs 2. Reduces recoil pressure of smaller alveoli more than larger alveoli (helps have a healthy compliance level)
126
What is the law of Laplace?
pressure = 2 (tension)/radius
127
True or False Compliance is the change in volume divided by the change in pressure
True
128
Without surfactant what would occur within two different sizes of alveoli?
- T1=T2 - Pressure would be higher in the smaller alveoli - Pressure would follow its gradient going from the smaller alveoli to the larger one causing the smaller one to collapse
129
With surfactant what would occur within two different sizes of alveoli?
- Surface tension is proportional to radius - Pressures will remain the same (P1=P2)
130
To change the pressure and get flow we need to overcome what?
resistance
131
Airway resistance is influenced by what 2 factors?
1. Physical Factors 2. Neurological
132
What are examples of physical factors that influence airway resistance?
- transpulmonary pressure - mucous accumulation
133
What are examples of neurological factors that influence airway resistance?
- PNS: releases Ach which constricts the smooth muscles, aka decreasing the radius - SNS releases Epinephrine which dilates smooth muscle, aka increases radius - Histamine constricts
134
What is asthma?
inflammation in the airways leading to broncho-constriction
135
What are 3 common triggers of asthma?
- exercise - smoke - pollutants
136
What are the 2 ways we treat asthma?
1. Anti-inflammatory drugs - leukotriene inhibitors - inhaled cortical steroids 2. Bronchodilators - Relax the airways (i) Mimic epinephrine - relaxes the smooth muscles (ii) inhibit acetylcholine
137
What is 3 common causes of COPD?
- smoking - secondhand smoke - environment with poor air quality
138
What is the main difference between COPD and asthma?
- COPD has excess mucous production in the small airways - The cause of asthma is mainly genetic
139
COPD is characterized by 2 sub diseases which are what?
1. Emphysema 2. Chronic bronchitis
140
Airway resistance is dependent on 3 factors which are?
1. Size of tube (fixed) 2. Interactions between gas molecules 3. Airway radius (most important)
141
True or False A decreased radius means increased pressure
True
142
True or False As transpulmonary pressure /recoil pressure increases, lung volume increases, and airway resistance decreases as we breathe in
True, as we breathe we increase the volume of the lung
143
What are the treatments for COPD?
- similar to asthma - even with a puffer, the symptoms can only be partially reversible
144
Each disease with resistance to the airways causes 3 disturbances which are what?
1. Increases work of breathing 2. Compromises gas exchange 3. Impaired oxygenation of blood
145
What are the 2 causes of a restrictive disease?
1. pulmonary fibrosis (thickening of elastic tissue) 2. neuromuscular disorder
146
how do we measure lung volume and capacities?
we look at the change in air volume that is displaced by inspiration and expiration - via spirometer
147
True or False The change in volume is a function of time, in reference to flow
True
148
What is Tidal Volume? (Vt)
the volume of air entering or leaving the lungs during one breath - average value under resting conditions
149
What is Inspiratory reserve volume? (IRV)
EXTRA volume that can be maximally inspired over the above typical resting tidal volume
150
What is Inspiratory capacity? (IC)
Max volume that can be inspired - starting from the end of a normal expiration (IC = IRV + VT)
151
What is Expiratory reserve volume? (ERV)
Max volume that can be actively expired starting from the end of a typical resting tidal volume
152
Will we always have a residual volume?
yes, if we have healthy lungs
153
What is the functional capacity that we have control over? aka doing a big breath in or out
Vital capacity
154
What are 3 examples of neuromuscular disorders?
1. Polio 2. Amyotrophic lateral sclerosis (ALS) 3. Muscular dystrophy
155
What does a spirogram do?
tracks the change in volume
156
True or False There is 21% oxygen
True
157
What is Residual Volume?
the volume of air remaining in the lungs after a maximal expiration
158
True or False Residual lung volume is about 1/4 of your total lung capacity give or take
True
159
What is Function residual capacity? (FRC)
the volume of air in the lungs at the end of a normal passive expiration (FRC = ERV +RV)
160
What is Vital capacity? (VC)
max volume of air that can be moved out during a one-breath after a maximum inspiration (VC = IRV + VT + ERV)
161
What is Total lung capacity?
max volume of air that the lungs can hold (TLC= VC +RV)
162
True or False The TLC, VC and RV are typically fixed numbers
True
163
From a respiratory mechanics point of view, what does the FRC represent?
natural relaxation volume of the respiratory system - volume where there is a balance between the outwards chest wall forces and the inwards elastic recoil forces of the lung
164
True or False If the FRC goes up in a clinical disease the IC will go down
True
165
When can our FRC change?
- when exercising - if we have asthma
166
What are the 2 force maneuvers?
- Forced expiratory volume in one second (FEV1) - Forced vital capacity (FVC)
167
What is FEV1?
- the volume of air expired during the 1st second of a maximal expiratory effort from TLC - how much air did you move out with the volume of air you expired in one second
168
What is FVC?
- similar to VC - measured during max expiratory effort starting from TLC
169
How much air can we forcefully expire in the 1st second. (HEALTHY LUNG)
70%-80%, 0.7-0.8
170
What are the 3 factors/point that are affects with COPD (obstruction)?
1. They are able to inflate their lungs 2. Trouble with expiring - due to narrowing airways - loss or elastic recoil - highly compliant lungs 3. Flow limitation on expiring results in a lower FEV1/FVC ratio
171
What is the typical FEV1/FVC ratio for a highly compliant lung?
less than 0.7
172
What are the 2 factors/point that are affects with ILD (restrictive)?
1. Cannot inflate sufficiently - poor lung compliance - stiff lungs - Low FEV1 due to a low FVC 2. Flow will either mimic a normal lung or be higher
173
What is the typical FEV1/FVC ratio for a poorly compliant lung?
more than 0.7, sever restrictions can increase to over 0.8
174
What is ventilation?
the movement of air in and out of the alveoli
175
What is the unit of ventilation?
per minute as a rate
176
What is the ventilation rate if you are holding your breath and there is no air moving in or out?
0, no ventilation rate
177
What is the size of our typical breath?
500 ml
178
What are the 2 types of ventilation we obtain when breathing in?
1. Dead space 2. Alveolar ventilation
179
What percentage of gas that we breathe in will not reach the gas exchange zones?
30%
180
What percentage of gas that we breathe in will be considered alveolar ventilation?
70%
181
What is Ve?
the total volume of expired ventilation
182
Why do we care more about expired rather than rate than inspired when talking about ventilation?
expired will have higher CO2 values
183
How do we know if alveolar ventilation is sufficient?
- if we look at our arterial O2 content (96-100% Hb saturated)
184
What do we monitor to know if we are breathing enough?
alveolar CO2 (36-40 mm Hg)
185
with regards to alveolar ventilation, If our Va goes down, what happens to our PaCO2?
goes up
186
with regards to alveolar ventilation, If our Va goes up, what happens to our PaCO2?
goes down
187
At what 2 points does gas exchange occur?
1. lungs 2. peripheral tissue
188
True or False O2 and CO2 follow partial pressure gradients
True
189
What are 3 additional factors that affect the rate of gas transfer?
1. As surface area increases, the rate increases - bigger breather recruits more alveoli 2. Increased thickness in the barrier or air and blood will decrease the rate 3. The rate of gas exchange is directly proportional to the diffusion coefficient of the gas
190
Diffusion is passive therefore it travels from where to where?
High to low
191
True or False Is the gas concentration of oxygen in this room the same as in Everest?
True, but the partial pressure will drop
192
Atmospheric air is composed of 3 elements which are what?
1. Nitrogen 2. Oxygen 3. Carbon Dioxide
193
What is the percentage of Nitrogen?
79.04%
194
What is the percentage of Oxygen?
20.93%
195
What is the percentage of Carbon dioxide?
0.03%
196
What is the Atmospheric pressure at sea level?
760 mm Hg
197
True or False As the altitude goes up, the atmospheric pressure goes down and therefore the the partial pressure will go down
True
198
In a scenario where we are in a plane and there is a loss of cabin pressure, our PO2 will be very low how do we get it back up?
By using the oxygen tanks which are almost 100 percent oxygen, therefore we change the oxygen fraction from 0.2093 to something else
199
True or False If we want to increase the PO2 at a high altitude we would need to increase the fraction
True
200
When we breathe out, what are the percentages of Nitrogen, Oxygen and Carbon dioxide?
Nitrogen = 79.95% Oxygen = 15.85% Carbon dioxide = 4.2%
201
What 2 factors that help to facilitate diffusion?
1. Pressure differences in alveoli 2. Capillaries
202
What is the set point we want to keep our arterial CO2 at?
36-40 millimeters of mercury
203
What is Henry’s law?
The volume of gas dissolved in a liquid is proportional to the partial pressure of the gas
204
what does “C gas” equal?
concentration of gas in a liquid (ml/dl)
205
What does “k” equal?
solubility coefficient of the gas in the liquid
206
A higher k value means what?
less pressure is required to dissolve gas
207
True or False O2 and CO2 have different solubility coefficients
True
208
In the atmospheric air, the PO2 is what?
160
209
When the oxygen gets to the alveoli what is the PO2 at now?
100
210
When the oxygen gets to the venous what is the PO2 at now?
40
211
True or False Generally, the arterial PaO2 and the alveolar PAO2 in a perfect lung are the same
True, meaning that there is not any leakage in the interstitial space
212
What is an example where the PaO2 and the PAO2 are not equal?
Any interstitial lung disease, where you get a widening of that interstitial space - pulmonary fibrosis - cystic fibrosis
213
Is there ever a 0 PO2?
No
214
What is the PCO2 in the tissues?
greater than 46
215
What is the PVCO2?
about 46 or slightly higher
216
What is the PCO2 when we expire?
40
217
What is the PACO2 and the PaCO2?
40
218
In a scenario where we are not breathing enough what is happening?
the build-up of CO2, can’t breathe out the CO2
219
What is hypercapnia?
build-up of CO2 lack of O2
220
What is hyperventilation?
where we increase our ventilation relative to the production of CO2
221
What happens to your PCO2 and your PaCO2 during hyperventilation?
decreases
222
What happens to our PaO2 during hyperventilation?
increased
223
What is hypoventilation?
under ventilating, not breathing enough
224
What happens to our PCO2 during hypoventilation?
increases
225
What are the 4 factors that can affect the alveolar pressure of oxygen PAO2?
1. Decreased PO2 in inspiration (high altitude) = decreased 2. Increased alveolar ventilation and unchanged metabolism = increased 3. Increased metabolism and unchanged alveolar ventilation = decreased 4. Exercise, equal metabolism and VA = No change
226
What are the 4 factors that can affect the alveolar pressure of oxygen PACO2?
1. Decreased PO2 in inspiration (high altitude) = No change 2. Increased alveolar ventilation and unchanged metabolism = decreased 3. Increased metabolism and unchanged alveolar ventilation = increased 4. Exercise, equal metabolism and VA = No change
227
What is ventilation-perfusion matching?
matching of the airflow to the alveoli and the blood flow to the capillary or the tissue
228
What is perfusion defined as?
blood flow to a tissue or an organ
229
What is a shunt?
when there is no ventilation to provide the blood with oxygen and therefore it remains deoxygenated and then gets pumped back into the left heart into circulation
230
If we have too many shunts taking place what will happen to our arterial PO2?
decrease
231
What is the normal ventilation to capillary perfusion rate?
1/1 or V/Q
232
What would the V/Q ratio look like in a shunt?
0/1
233
What is alveolar/pure dead space
when there is no blood flow but there is ventilation - no capillary perfusion, for whatever reason - therefore ventilation goes down to take place in gas exchange with the capillaries but there is no blood available so gas exchange does not occur
234
What does the V/Q ratio look like for alveolar/pure dead space?
1/0
235
The shunt will cause high or low PO2?
low
236
How do we counteract mismatched blood flow?
reflex hypoxic vasoconstriction of pulmonary arterioles
237
what does hypoxic vasoconstriction do?
helps to maintain highly efficient and effective gas exchange
238
what is hypoxic vasoconstriction
a reflex that helps minimize the areas of low ventilation-perfusion ratio
239
In which disease can we lose out on hypoxic pulmonary vasoconstriction
emphysema
240
What are 2 ways we increase perfusion throughout the lung
1. lying down 2. exercise
241
True or False In emphysema, the surface area for gas exchange is decreased
True
242
What happens to your arterial PO2 in the case of exercising with ILD or pulmonary Edema?
PO2 will drop
243
What are the 2 methods of gas transport in the blood for OXYGEN?
1. Physically dissolved 2. Bound to Hb
244
What are the 3 methods of gas transport in the blood for Carbon Dioxide?
1. Physically dissolved 2. Bound to hemoglobin 3. As bicarbonate (HCO3)
245
What is blood doping?
inject “hemoglobin” to have more O2 transport capabilities
246
What is the percent that oxygen can be carried by physically dissolved?
1.5- 2 percent
247
What is the percent that oxygen can bind to hemoglobin?
98-98.5 percent
248
What is oxyhemoglobin?
this is when haemoglobin combines with oxygen
249
When the partial pressure of oxygen is high, what is happening to oxygen?
oxygen will bind to hemoglobin
250
When the partial pressure of oxygen is low, what is happening to oxygen?
Oxygen will “unbind” from hemoglobin
251
At the lung levels is there a tendency for oxygen and hemoglobin to combine?
yes
252
At the tissue levels is there a tendency for oxygen and hemoglobin to dissociate?
yes
253
1 single hemoglobin is composed of what?
1. 4 heme groups/molecule 2. 4 globin subunits/molecules 3. 4 O2 molecules
253
What is the average amount of oxygen we need in the blood per minute for basal function?
250ml O2/min
254
How many O2 molecules can bind one hemoglobin molecule?
4, one per heme group
255
where is hemoglobin found?
in RBC
256
Does Oxyhemoglobin have any pressure?
No
257
For 1 gram of hemoglobin how many ml of O2 can it bind?
1.34 ml/g of O2
258
What is the general concentration of hemoglobin in the blood?
15g/100ml of blood
259
What 2 factors determines O2 carrying capacity?
1. Total amount of Hb 2. PO2 (alveolar and arterial)
260
if you have emphysema, or any obstructive lung disorder than your PO2 in the arterial blood is going to be a little bit lower, because of what?
because less oxygen is getting across in the first place
261
What is the relationship that is being measured on an oxygen hemoglobin dissociation curve?
PO2 of the arterial blood and the % of Hb saturation
262
At the sight of gas exchange what is the arterial PO2 of the blood? (at the lungs)
100 mmHg
263
At the sight right after gas exchange at the tissues what is the arterial PO2 of the blood? (veinous circulation)
40 mmHg
264
True or False The percent of oxyHb is high where the partial pressure of oxygen is high? (lungs)
True
265
True or False The percent of oxyHb is low where the partial pressure of oxygen is low? (tissue)
True
266
What is a scenario where oxygen does not have enough time to bind to Hb?
1. Really heavy exercises 2. Diffusion limitations
267
What is the Bohr effect?
when the oxygen hemoglobin dissociation curve is shifter to the right, aka favouring dissociation
268
True or False The partial pressure of oxygen is the main factor determining the percentage of Hb saturation
True
269
On the oxygen hemoglobin dissociation curve what does the plateau/flat part represent?
where PO2 can be at 60 or greater for sufficient Hb situations - at the level of the lungs
270
On the oxygen hemoglobin dissociation curve what does the steep part represent?
at the level of the tissue - where PO2 is dropping making the affinity for oxygen low
271
When does the affinity of O2 to Hb drop?
approx 60 mmHg
272
True or False Hb is responsible for 98% of O2 transport from the lungs to the tissue
True
273
Can we have a slightly lower PO2 and be fully oxygenated from an O2- Hb saturation point of view?
Yes, the buffer period greater than 60
274
Why would breathing too much oxygen be hurtful?
having chronic high levels of oxygen can lead to oxidative stress in the blood vessels
275
True or False If we are already normally saturated with 98,99% saturation, breathing supplemental pure oxygen is not going to increase your oxygen saturation
True, because oxygen will follow concentration gradients but we cannot double the amount of Hb saturation
276
As we go higher in altitude what is happening to our oxygen saturation? is it getting higher or lower?
Lower, the percent oxygen saturation falls
277
At what altitude can we be almost fully saturated? (highest altitude to be fully saturated)
approx 20,000
278
if we go from 22,000-25,000, what would happen to our oxygen saturation?
almost cut in half
279
Somebody with anemia will have less of what?
Hb
280
Will the O2 dissociation curve for individuals with anemia look the same compared to a healthy individual?
yes, because their Hb will be fully saturated they just happened to have less Hb
281
Will the amount of O2 in the blood be the same, lower or higher for an individual with anemia compared to a healthy individual?
lower, because there is less Hb available
282
What are 3 physiological factors that can change the O2 dissociation curve?
1. High arterial PCO2 2. High acidity/decrease in pH in the blood 3. Increased temperatures
283
When would we see a rightward shift in the dissociation curve?
during exercise, all of the physiological factors would be occurring
284
The Bohr effect is when we have what?
1. increased PCO2 2. increased acidity 3. Increased temperatures 4. Increases BPG 2-3
285
True or False The Bohr effect promotes the unloading of oxygen
True
286
Where is CO2 being produced?
In the tissues
287
What are the 3 byproducts of internal respiration?
1. CO2 2. Water 3. Energy
288
What drives CO2 in the blood?
diffusion movements aka concentration gradients
289
What are the 3 ways CO2 is transported?
1. Dissolved in plasma 2. Bound to Hb 3. Converted to bicarbonate
290
What % of CO2 is transported by being dissolved in the plasma?
10%
291
What % of CO2 is transported by being bound to Hb?
30%
292
What % of CO2 is transported by being converted to bicarbonate?
60%
293
Do we want many hydrogen ions in the blood? (H+)
No, because it can disturb internal cellular respiration
294
Hydrogen ions bind to what?
deoxyhemoglobin (Hb)
295
What is hydrogen called when it is binding to hemoglobin?
hydroxy hemoglobin
296
What is the percentage of oxygen that is saturated in the venous circulation? (in the blood being pumped from the tissues to the lungs)
60-70 percent saturated with oxygen
297
What does that mean if the venous blood is only 60-70% saturated with oxygen?
There is some room to bind with carbon dioxide
298
What is the bicarbonate equilibrium reaction?
carbon dioxide and water (combined) - carbonic anhydrase (enyme) = carbonic acid Carbonic acid can dissociate to make = bicarbonate and hydrogen ion
299
When will the bicarbonate reaction go from left the right?
at the level of the tissue
300
When will the bicarbonate reaction go from right to left?
at the level of the lungs
301
What is it called with CO2 binds with Hb?
carboxyhemoglobin
302
What is the hamburger effect, aka the Chloride shift?
This is when HCO3- (bicarbonate) diffuses out of the red blood cell in the plasma and is replaced by a Cl- (chloride ion)
303
What is the reason for the chloride shift?
to ensure that bicarbonate leaves the red blood cell, to make sure it does not rebind with free-floating hydrogen ions
304
Why would we have to replace HCO3- with Cl- as opposed to simply just removing the HCO3-?
Because we need to keep the red blood cell neutral, the HCO3 opposes the positive hydrogen ion (H+), meaning when it leaves, it needs to have another negative ion take its place. ie. Chloride
305
High CO2 is in the tissue, which drives the reaction in what way?
left to right
306
Low CO2 is in the lungs, which drives the reaction in what way?
right to left
307
What is keeping the red blood cell stable?
Chloride shift
308
If we have an unchanged/equal metabolic rate and pick up our breathing, what will happen?
hyperventilating aka breathing too much - O2 will increase - CO2 will decrease
309
If the ventilation is unchanged/equal and we increase metabolic rate without picking up our breathing, what will happen?
Hypoventilation, aka not breathing enough - O2 will decrease - CO2 will increase
310
What will happen to O2 and CO2 when we increase our metabolic rate and pick up our breathing, aka increase ventilation?
O2 and CO2 will remain steady
311
Where is breathing generated?
level of the medulla, in the brain stem
312
What are the 2 groups in the medullary respiratory centre called?
1. Dorsal respiratory group (DRG) 2. Ventral respiratory group (VRG)
313
What kind of neurons do the dorsal respiratory group and the ventral respiratory group both control?
Inspiratory neurons
314
Which respiratory group controls expiratory neurons?
ventral respiratory group
315
Why do we need more neurons for inspiration?
Because we have to activate our inspiratory muscles, we need to tell the diaphragm what to do via the phrenic nerve
316
Where is the Pre-Botzinger complex?
Within the medulla
317
What does the Pre-Botzinger complex do?
generates the respiratory rhythm - size and frequency of the breath
318
What are the 3 types of receptors that control the respiratory pattern?
1. Mechanoreceptors 2. Metaboreceptors 3. Pulmonary receptors
319
What do mechanoreceptors do?
detect changes in pressure or displacement of a structure and sends this information to the medulla
320
What are examples of changes that the mechanoreceptors would pick up on?
- lung and chest wall - peripheral muscles
321
What do metaborcepetors do?
Detect local changes in metabolic byproduct concentration and send this information to the medulla
322
What are examples of changes that the metaborcepetors would pick up on?
changes in lactate or hydropgen
323
What do pulmonary receptors do?
Detects a change in the stretch of the lung
324
What are chemical controls/chemoreceptors?
sense fluctuations of O2 and CO2 in the blood to maintain our breathing
325
What are the 2 types of chemoreceptors?
1. Peripheral receptors 2. Central Medullary receptors
326
What are the 2 peripheral chemoreceptors?
1. Carotid 2. Aortic
327
True or False The carotid and aortic chemoreceptors both respond to changes in the arterial blood gas concentration or partial pressures and send signals to the medulla
True
328
Which body plays a larger role and is more sensitive?
carotid
329
True or False The carotid body is much more dominant, aka it's more important
True
330
The peripheral carotid chemoreceptor is predominantly a sensor for what?
Oxygen
331
How much can we increase and decrease PO2 with almost no change in our minute ventilation?
+20 or -40 mm Hg of PO2, 60 mm Hg
332
When would the carotid peripheral chemoreceptor become active?
after the arterial PO2 reaches about 60 or lower, it sends a signal to increase our breathing
333
True or False When the PaO2 decreases, the receptors increase their rate of discharge
True
334
True or False When the rate of firing (excitatory stimuli) increases our ventilation increases, meaning what exactly?
True, meaning increased ventilation is directly proportional to ventilation
335
What kind of feedback is being used with the peripheral chemoreceptors?
Negative feedback brings us back to breathing, aka back to homeostasis
336
If we have an increase of H+, can that also stimulate the carotid chemoreceptor?
yessir
337
What are the 2 scenarios where there is an increase of H+ in the cell?
1. Diarrhea - loss of lactic acid or HCO3- 2. Maximal exercise - where H* exceeds HCO3- buffering capacity
338
Where are central chemoreceptors located?
medulla
339
What do central chemoreceptors do?
- sense changes within the brain’s extracellular fluid or the cerebrospinal fluid - respond to changes of H+ (pH) in the medulla
340
Can hydrogen pass the blood-brain barrier?
No, not alone as a hydrogen molecule
341
Can carbon dioxide pass the blood-brain barrier?
Yes, it can
342
When the cerebrospinal fluid senses hydrogen where is the hydrogen coming from?
it is the hydrogen from the arterial CO2
343
The CO2 in the blood leads to increased what?
Ventilation via the bicarbonate equilibrium
344
The central chemoreceptors respond to what?
CO2 fluctuations, via an increased Hydrogen in the cerebrospinal fluid
345
Low O2 is sensed by which sensors?
carotid peripheral chemoreceptors
346
High CO2 is sensed by which sensors?
central chemoreceptors