Chapter 16 Part 2 - Respiratory Physiology Flashcards
1
Q
The respiratory system works together with the cardiovascular system to create the _______________ system
A
cardiopulmonary system
2
Q
What “things” are a part of or go on in the cardiopulmonary system?
A
- blood vessels
- blood gasses (O2, CO2)
- gas exchange (@ pulmonary capillaries, systemic capillaries)
3
Q
What is the function of the cardiopulmonary/respiratory system?
A
oxygenate blood at the lungs (for the tissue; O2 loads onto Hb and Hb will unload O2 to the tissue)
remove CO2 (toxic waste) from the tissue
4
Q
Be able to follow air flow through all of the anatomical parts of the respiratory system.
Name the different zones and identify which anatomic parts are a part of the named zones.
A
Nasal passage ⮕ nasal cavity ⮕ pharynx (throat) ⮕ larynx (voicebox) ⮕ trachea ⮕ R and L primary bronchi ⮕ secondary bronchi ⮕ tertiary bronchi ⮕ terminal bronchioles ⮕
(Conducting Zone/URT)
respiratory bronchioles ⮕ alveoli/alveolar sacs
(Respiratory Zone/LRT)
5
Q
What is the function of the conducting zone/URT?
A
conduct air into lungs
6
Q
What is the function of the respiratory zone/LRT?
A
site of pulmonary gas exchange
7
Q
Breathing is also called ___________ ____________
A
pulmonary ventilation
8
Q
Name the two parts of pulmonary ventilation
A
inspiration = breathing in
expiration = breathing out
9
Q
How is pulmonary ventilation achieved?
A
changing thoracic cavity/lung volume
10
Q
What are the major muscles (discussed in class) involved in pulmonary ventilation/breathing?
A
Diaphragm
External intercostal muscles
Internal intercostal muscles
11
Q
Describe the “function” of the diaphragm
A
inspiration: contracts and lowers, making thoracic cavity larger (flat)
⬆Volume = ⬇Pressure
expiration: relaxes and raises, making thoracic cavity smaller (dome shape)
⬇Volume = ⬆Pressure
12
Q
Describe the function of the external intercostal muscles
A
raises rib cage (up and out) during inspiration
⬆Volume = ⬇Pressure
13
Q
Describe the function of the internal intercostal muscle
A
lowers rib cage (down and in) during expiration
⬇Volume = ⬆Pressure
14
Q
How are volume and pressure related to each other?
A
Inversely related
⬆Volume = ⬇Pressure
⬇Volume = ⬆Pressure
15
Q
What determines the direction of airflow?
A
pressure gradient
(pressure will always move from high to low)
16
Q
TRUE or FALSE: Atmospheric pressure can decrease or increase depending on if the person is at rest, inhaling, or exhaling.
A
False, atmospheric pressure is constant because it is based on the environment
17
Q
What happens if intrapulmonary pressure is greater than intrapleural pressure, vs if intrapleural pressure is greater than intrapulmonary pressure?
A
Intrapulmonary > intrapleural: lungs remain inflated
Intrapleural > intrapulmonary: lungs will collapse
18
Q
Why is there no air movement at rest?
A
There is no air movement at rest because the atmospheric pressure and intrapulmonary pressure are the same (for a short period of time)
19
Q
What is the value of atmospheric pressure when lungs are at rest, are inhaling, and are exhaling?
A
760 mmHg
(is constant)
20
Q
What is the value of intrapulmonary pressure when lungs are at rest, are inhaling, and are exhaling?
A
At rest: 760 mmHg
Inspiration: 757 mmHg
Expiration: 763 mmHg
21
Q
What is the value of intrapleural pressure when lungs are at rest, are inhaling, and are exhaling?
A
At rest: 756 mmHg
Inspiration: 754 mmHg
Expiration: 757 mmHg
22
Q
Why is intrapleural pressure always below 760 mm Hg in a healthy person? (hint – what do the alveoli & chest wall naturally want to do?)
A
Alveoli wants to recoil inward while chest wall wants to recoil outwards
23
Q
If intrapleural pressure is 754 mm Hg and intrapulmonary pressure is 757 mm Hg, what will happen?
A
inspiration (lungs are inflated)
24
Q
When determining the direction of airflow, what which pressure values are you comparing?
A
Atmospheric ℗ vs Intrapulmonary ℗
25
# Are the lungs at rest, or is inspiration or expiration occuring?
Atmospheric pressure: 760mmHg
Intrapulmonary pressure: 760mmHg
Intrapleural pressure: 756 mmHg
at rest
(because atm℗ is equal to intrapulmonary ℗)
26
# Are the lungs at rest, or is inspiration or expiration occuring?
Atmospheric pressure: 760mmHg
Intrapulmonary pressure: 757mmHg
Intrapleural pressure: 754 mmHg
inspiration
(pressure decreases in lungs = volume is increasing = taking in O2 = inspiration)
diaphragm contracts and external intercostals raises rib cage (up and out)
27
# Are the lungs at rest, or is inspiration or expiration occuring?
Atmospheric pressure: 760mmHg
Intrapulmonary pressure: 763mmHg
Intrapleural pressure: 757 mmHg
expiration
(pressure increases in lungs = decrease volume = expiration)
diaphram relaxes and internal intercostals lower ribcage (in and down)
28
At rest, ________ pressure is greater than ___________ pressure. This is because lungs are __________ inflated to prevent smaller alveolar spaces from ____________
intrapulmonary (760)
intrapleural (756)
partially
collapsing
29
During inspiration, what explains why both intrapulmonary pressure and intrapleural pressure decrease (compared to resting state)
diaphragm and intercostals contract to move diaphragm flat and ribcage up and out -> increase in thoracic cavity volume = decrease in pressure
30
What is transpulmonary pressure?
intrapulmonary ℗ - intrapleural ℗
31
Why is the transpulmonary pressure always a positive value?
is positive because lungs remain partially inflated so the intrapulmonary ℗ needs to be greater than intrapleural ℗
(if it wasn't, this means that the lungs are/had collapsed)
32
Calculate the transpulmonary pressure for the lungs at rest, inhaling, and exhaling
at rest: +4
inspiration: +3
expiration: +6
33
As inspired air gets deeper in the body, it is...
- warmed
- filtered (cleaned)
- humidified
- channels into small spaces of alveoli -> site of gas exchange
34
Why does inspired air need to be warmed
tissue is sensitive to cold air
35
How is inspired air filtered(cleaned)
by nose hairs and ciliated cells in trachea
36
Why does inspired air need to be humidified?
needs to gain water vapor (from watery mucous lining) because if not, the dry air dehydrates alveolar space and damages alveolar cells
37
Explain why a person will have difficulty inflating their lung in the condition called pneumothorax.
Pneumothorax is a condition in which air goes into the pleural cavity (?)
Air pressure increases in the pleural cavity (because air wants to move from atmosphere; high to pleural cavity; low). If pressure increases more than intrapulmonary pressure, the lungs will collapse
38
TRUE or FALSE: A contracted diaphragm and contracted external intercostal muscles lead to inspiration
True
39
TRUE or FALSE: A relaxed diaphragm and contracted external intercostal muscles lead to expiration
False, relaxed diaphragm and contracted INTERNAL intercostal muscles for expiration.
40
*Describe the mechanism that takes place if the intrapulmonary pressure is 763 mm Hg and then drops to 757mmHg.
Inspiration occurs as the diaphragm contracts and external intercostal muscles raise ribs up and out, which both work to increase volume = decrease pressure
41
*Regarding gas exchange, what is the overall goal of inspiration vs. expiration?
Take in oxygen (for aerobic cellular respiration) and expel CO2 (toxic waste)
42
At what “TWO” locations in the body does gas exchange occur?
Pulmonary capillaries/alveoli or lung
Systemic capillaries/body tissue
43
TRUE or FALSE: Atmospheric pressure is composed of several types of gasses, creating a gas mixture.
If true, name the gasses involved. If false, name the only gas.
True, contains a gas mixture
O2, CO2, N2, H2O vapor
44
Which gas in the gas mixture in the atmosphere is the most abundant?
What percentage of the atmosphere does N2 make up?
What is the partial pressure of N2 (PN2)?
N2
79%
601 mmHg
45
What percent of the atmosphere does O2 make up?
What is the partial pressure of O2 (PO2)?
21%
159 mmHg (out of 760)
46
Define total pressure (of gas mixture)
equal to the sum of the pressures of each gas in it
47
At sea level, what is the total atmospheric pressure?
760 mmHg; or 1 atmosphere (atm)
48
Define partial pressure
is the pressure of an individual gas that can be measured by multiplying the % of that gas by total pressure
ex: O2 makes up 21% of the atmosphere, so partial pressure of O2 (PO2) = 760 x 0.21 = 159 mmHg (out of 760)
49
Know the partial pressure of all the gases and compare it to inspired air to the alveolar air
INSPIRED AIR - total pressure = 760
H2O - variable
CO2 - 000.3 mmHg
O2 - 159 mmHg
N2 - 601 mmHg
ALVEOLAR AIR - total pressure = 760
H20 - 47 mmHg
CO2 - 40 mmHg
O2 - 105 mmHg
N2 - 568 mmHg
50
Why does the partial pressure of H2O increase in alveolar air?
As a result of gas exchange, explain the changes of CO2 and O2 partial pressures in alveolar air compared to inspired air
H2O - air was humidified = increase in H2O
ALVEOLAR AIR
CO2 = increases (because it receives CO2 as a waste product from CR through deoxygenated blood)
O2 = decreases (lungs oxygenate blood to be unloaded to tissue)
51
TRUE or FALSE: after gas exchange, in alveolar air, the percentage partial pressure of O2 DECREASES and CO2 INCREASES, which does NOT change the partial pressure of each
False, partial pressure of ALL gasses (including O2 and CO2) will change, but will still add up to 760 mmHg in alveolar air
52
air becomes humid when it gets into the ______
lungs
53
*Why is PO2 lower in the pulmonary artery than in the pulmonary vein? Why is PCO2 higher in the pulmonary artery than in the pulmonary vein?
PO2 is lower in the pulmonary artery, but is higher than PCO2 than the pulmonary vein because the pulmonary artery carries deoxygenated blood, with PO2 value of only 40 mmHg and a PCO2 value of 46 mmHg. Gasses move from high to low, so O2 gas diffuses from the alveoli and into the pulmonary capillaries and CO2 gas diffuses from the pulmonary capillaries to the alveoli. Because of this gas exchange, pulmonary vein now has a higher PO2 of 100 mmHg and a lower PO2 value of 40 mmHg
54
What happens to the HCO3- when it is present in the blood plasma at the level of the pulmonary capillaries?
HCO3- enters the RBC via reverse chloride shift and combines with H+ and becomes H2CO3 via CA and then becomes CO2 + H2O via CA. CO2 can now diffuse out of the RBC and into the alveolus to be exhaled out
55
In terms of PCO2 values, explain why CO2 leaves the pulmonary capillary and enters the alveolus
PCO2 values in the pulmonary capillary (46) is higher than in the alveolus (40). Gas wants to move from high to low, so CO2 diffuses out the pulmonary capillary and into the alveolus
56
Define the Haldane Effect and explain how it happens
Occurs in pulmonary capillaries and explains the detachment of CO2 from Hb
Hb prefers to bind to O2, so Hb-CO2 in the RBC will become Hb-O2 (because O2 bumped off CO2; loading of O2 to Hb). There is now free CO2 in RBC and will enter the alveolus in exchange for O2
57
TRUE or FALSE: If HCO3- is high in the RBC at the pulmonary capillary, then CO2 will decrease
False, high levels of HCO3- promoted CO2 formation in RBC, meaning CO2 levels will increase as HCO3- increases
58
Name and describe the two types of alveolar cells that make up the alveolus
Type 1: makes up majority of total surface area and is where gas exchange occurs
Type 2: secretes pulmonary surfactant (lipid; to keep lungs inflated) and reabsorbs Na+ and H2O, to prevent fluid buildup
59
What is normally present inside of an alveolus?
Thin H2O film and some mucus
60
What is a CFTR channel and describe its function
Is a protein Cl- channel on alveolar cells (type I) that functions to transport Cl- out of alveolar cells and into alveolar space H20 film
61
*What does it mean when we say that the water film inside the alveolus is hypertonic/increases in ionic concentration? As a result of this, where does the water go that was present inside the type 1 alveolar cell?
The hypertonic water film contains high ionic concentrations of Na+ and Cl-
Water is attracted to the hypertonic concentration and will move out of the type one alveolar cell and into the alveolar space
62
Explain why it is difficult to perform gas exchange if the CFTR channel is blocked
If blocked, Cl- ions will not move into the alveolar space, which prevents Na+ from also moving into the alveolar space. This will decrease ionic concentration in the H2O film and it will NOT become hypertonic. Water will not move into the alveolar space (via osmosis) and dry, thick mucus will build up in the alveolar space. This thickness makes it difficult for gas exchange because gases can only pass through thin substances.
63
Is breathing/ventilation under voluntary control, involuntary control, or both? Regarding involuntary control, what part of the CNS regulates breathing
involuntary
Medulla oblongata + pons
64
Name the three areas/centers that are a part of the respiratory control center, their specific locations in the CNS and their functions
rythmicity area - medulla oblongata - generates involuntary/automatic breathing and contains inspiratory and expiratory neurons
Apneustic center - pons - promotes inspiration by stimulating inspiratory neurons
Pneumotaxic center - pons - inhibits apneustic center to inhibit inspiration and promote expiration
65
Why does hypoventilation lead to an increase in PCO2?
Hypoventilation means that CO2 cannot be exhaled adequately, so CO2 will building up, thus increasing PCO2
66
TRUE or FALSE: A decrease in PCO2 may be due to hypoventilation
False, hypoventilation leads to an increase in PCO2
67
TRUE or FALSE: If PCO2 is high in the blood, blood pH will decrease
True, ↑CO2 + H2O → H2CO3 → ↑H+ + HCO3-
↑H+ = more acidic = low pH
68
TRUE or FALSE: Central chemoreceptors in the neurons of the CNS/medulla oblongata directly detect CO2 concentrations which result in respiration
False, CO2 diffuses through the blood-brain barrier and gets converted into H+ (in CSF) in which the central chemoreceptors detect.
69
What is the PO2 and PCO2 value in the pulmonary artery?
PO2 = 40
PCO2 = 46
70
What is the PO2 and PCO2 value in the alveoli?
PO2 = 105
PCO2 = 40
71
What is the PO2 and PCO2 value in the pulmonary vein?
PO2 = 100
PCO2 = 40
72
Describe how gas exchange occurs occurs at the level of the lungs (for reverse cl- shift)
HCO3- originally left the RBC at systemic capillaries through the Cl- shift
travels through the blood plasma until it reaches the pulmonary capillaries
HCO3- enters the RBC via Reverse Chloride Shift
combines with H+ and is eventually turned into CO2 + H2O via CA
Because of this, PCO2 is now at 46 mmHg and in the alveolus, it is only 40 mmHg (move from high to low -> RBC to lung)
PO2 is high in alveolus at 105 mmHg and O2 is low in pulmonary capillaries at 40 mmHg, so will move from high to low -> oxygenate blood
CO2 moves into lungs from pulmonary capillaries is then exhaled out
73
TRUE or FALSE: In regards to the Haldane effect, CO2 will enter the alveolus if both the pulmonary capillaries and alveolus have the same pressure.
False, there must be a pressure difference in order for CO2 to enter the alveolus from the pulmonary capillaries
74
How do you calculate driving forces?
Attempt to calculate the driving force of PO2 as it moves from the alveoli to the pulmonary capillaries.
Hint: PO2 in alveoli is 105 mmHg. PO2 in pulmonary artery is 40 mmHg.
you have to subtract to see if there is a pressure difference
gas moves from high to low: 105 - 40 = 65mmHg
65mmHg is the driving force for oxygen to move from the alveoli to the pulmonary capillaries
75
In regards to the Haldane effect, high HCO3- in plasma promotes ________ formation in the RBC -> ______ gets exhaled
CO2
CO2
76
Where does the Haldane effect occur specifically? *not the pulmonary capillaries)
in RBC
77
Each alveolus is ______-cell layer thick
Why is this?
one
needs to be very thin so that gas exchange can occur
78
The alveolus/alveolar cells are covered/surrounded by __________ capillaries
blood/pulmonary
79
A thin film of H2O and mucus can be found on the inside of the alveolus.
Explain where/the sources H2O came from
first source: H2O came from inspired air (picks up H2O vapor -> contributes to H2O film)
second source: due to CFTR channel that transports Cl- out of alveolar cells and into alveolar space, in which H2O is attracted to
80
What type of channel is the CFTR channel?
protein/Cl- channel
81
CFTR channels are found on ________ cell membrane surfaces
many
82
TRUE or FALSE: CFTR channels are found on type 2 alveolar cells
False, are found on type 1 alveolar cells
83
Explain how the CFTR channel works to maintain watery, mucal lining in the alveolar space
CFTR is a Cl- channel that moves Cl- ions from alveolar cells into alveolar space
H2O layer becomes negative, which attracts Na+ and Na+ follows Cl-
This makes the H2O film hypertonic (increase ionic concentration) which promotes H2O movement out of the cell and into alveolar space by osmosis
H2O film prevents drying of lung tissue and keeps a thin, watery mucal lining of alveolar space -> BETTER GAS EXCHANGE
84
H2O film in the alveolus prevents ______ of lung tissue
desiccation (drying)
85
What are the three main parts of the brain stem?
Which of these **parts** are a part of the respiratory control center?
- midbrain
**- pons
- medulla oblongata**
86
What areas/centers are found in the medulla oblongata and pons?
medulla oblongata: rhythmicity area
pons: apneustic center and pnuemotaxic center
87
What is the function of the rhythmicity area in the medulla oblongata?
What do the "things" found in here do?
generate automatic breathing (12-20 breaths/min) and contains inspiratory and expiratory neurons
(ventilation volume = 500ml/breath)
(ventilation volume rate is 6-10 L/min)
inspiratory neurons: contract diaphragm and intercostals (external)
expiratory neurons: relax diaphragm and intercostals (internal)
88
What is the function of the apneustic center and pneumotaxic center in the pons?
apneustic center: promote inspiration by stimulating inspiratory neurons
pnemotaxic center: inhibits apneustic center to inhibit inspiration and promote expiration
89
Why does hypoventilation lead to a decrease in pH?
CO2 is not exhaled adequatley, meaning that CO2 will build up in the body
Increases of CO2 will increase H+, which decrease pH and make the blood acidic
90
Why does hyperventilation leave to a increase in pH?
CO2 is exhaled rapidly, meaning CO2 levels fall in the body
Decrease in CO2 will decrease H+, which increase pH and make the blood alkaline
91
Ventilation is controlled to maintain ______ levels of ______ in the blood at _______ mmHg
constant
CO2
40 mmHg
92
___________ are present in inspiratory and expiratory neurons of the medulla oblongata
chemoreceptors
93
What "thing" in inspiratory and expiratory neurons of the medulla oblongata stimulates respiration?
chemoreceptors
94
Describe how chemoreceptors on inspiratory and expiraory neurons of the medulla oblongata alter ventilation rate
arterial CO2 in capillaries crosses the blood brain barrier (BBB) and enters cerebrospinal fluid (CSF)
*NOTE: ONLY GASES CAN CROSS BBB*
CO2 reacts with water that is found in the CSF
produces H+ and HCO3- in the brian interstitial fluid
chemoreceptors in inspiratory and expiratory neurons (of medulla oblongata) detects change in H+ concentrations
this stimulates respiration (ex: increase in H+ will increase ventilation rate)
95
Why cant chemoreceptors of inspiratory and expiratory neurons (of medulla oblongata) detect H+ that was produced in capillaries?
only gases (like CO2) are able to cross the BBB into the CSF, in which it becomes H+ and HCO3-
ions (like H+) cannot cross the BBB and into the CSF, so it has to be produced in the CSF from a GAS = CO2
