3/25 Lecture Flashcards
1
Q
What are the two main gasses we are concerned with in blood gas physiology?
A
oxygen and carbon dioxide
2
Q
T/F: Oxygen is very soluble
A
F
Oxygen is not very soluble
3
Q
T/F: The PO2 in solution (in a beaker) is higher than the amount in the environment
A
F
The PO2 in solution (in a beaker) is the same as the amount in the environment
4
Q
Atmospheric oxygen pressure pushes the oxygen into a solution and the oxygen dissolved in solution will push ________ in the opposite direction
A
equally
5
Q
How much oxygen in a biological solution depends on the ___________.
A
solubility
6
Q
Most of our blood is measured in ________
A
deciliters (dL)
7
Q
If the PO2 in atmosphere is 100 mmHg, it will push oxygen into solution and the PO2 of the solution will be ____________.
A
100 mmHg
It will have the same partial pressure in the fluid and in the environment
8
Q
The quantity of a gas will always be measured in ____________
A
a volume (dL, mL, L)
9
Q
For every deciliter (dL) of solution (likely blood plasma), ________ mL of oxygen dissolves per mmHg of partial pressure of oxygen PO2
A
0.003
10
Q
What is the formula to find the dissolved oxygen content in the blood?
A
Dissovled O2 = 0.003 x PO2
11
Q
What is the dissolved O2 content if PVO2 = 40 mmHg per dL of solution?
A
(0.003) x 40 = 0.12 mL of O₂ per dL
12
Q
What is the solubility coefficent for dissolving oxygen gas in a solution?
A
(0.003 mL O2)
/
[(100 mL blood) x (PO2 in mmHg)]
13
Q
What are the two variables required to determine the amount of dissolved gas in a solution?
A
- PO2 of the solution
- Solubility coefficient
14
Q
Each deciliter of blood has ________ mL of O2 dissolved in it and the body requires ________ mL of O2 per minute to stay alive
A
0.3 mL ; 250 mL
15
Q
Why do we need hemoglobin?
A
There is not enough oxygen solubility to pack the amount of oxygen needed each dL of blood and hemoglobin helps get around this
16
Q
What is the abbreviation for hemoglobin?
A
Hb
17
Q
For each gram of Hb, we should be able to store/carry ________ mL/O2
A
1.34
18
Q
Hb assists with _____________
A
oxygen transport
19
Q
What is the oxygen carrying capacity of Hb if Hb is 15 g/dL?
A
20.1mL of O2 per dL
20
Q
The vast majority of oxygen in the blood is carried by _____________
A
Hemoglobin
21
Q
What are the two factors that determine how much oxygen is on Hb?
A
- Carrying capacity (how much O2 each g of Hb can carry and how much Hb we have in the sample
- Hb oxygen saturation number (ex: 100%, 50%)
22
Q
A normal hemoglobin is ________ per dL in an average healthy adult.
A
15 grams
23
Q
What gender tends to have a higher than average amount of Hb?
A
Men
24
Q
If a Hb oxygen saturation number is 100%, what does this mean?
A
All 4 subunits of the hemoglobin molecule are filled to capacity
25
What is the abbreviation for normal adult hemoglobin?
AHb or HbA
26
A normal adult hemoglobin is a ________ (molecular structure)
tetromer
27
What are the 4 componenet parts of normal adult hemoglobin?
How many O2 molecules can this carry?
2 alpha subunits
2 beta subunits
A total of 4 O2 molecules
28
If Hb saturation is very low at 10%, how many mLs of O2 are in the bound state (attached to Hb)?
2 mL/dL
29
What are the 4 componenet parts of fetal hemoglobin?
2 alpha subunits
2 gamma subunits
30
Between adult and fetal hemoglobin, which has a higher affinity to oxygen?
Fetal Hb
31
Why does fetal Hb have a higher affinity for oxygen?
When the fetus is developingin the womb, materal blood is passing through fetal circulation. If the fetus needs to pull oxygen from maternal blood, it helps that fetal Hb has a higher affinity than materal/adult Hb to be able to achieve that pull
32
When is fetal Hb replaced to adult Hb?
Soon after birth
33
One of the most significant contributors to deciding how much Hb is floating around is ________________
erythropoietin (EPO)
34
____________ is the kidney's growth hormone
erythropoietin (EPO)
35
Where is erythropoietin (EPO) produced?
In the kidneys
36
When the ________ parts of the kidney are hypoxic, erythropoietin (EPO) is released in response and more ________ are formed.
deep; RBCs
37
If the kidney's are not functioning well (ex: kidney failure) ____________ might be required to ensure that the body continues producings RBCs.
synthetic erythropoietin (EPO)
38
What blood disease did Dr. Schmidt say that erythropoietin (EPO) is particularly important for?
sickle cell
39
T/F: Myoglobin is structurally similar to Hb but it has less affinity for oxygen compared to adult Hb.
F
Myoglobin is structurally similar to Hb but it has a **HIGHER** affinity for oxygen compared to adult Hb.
40
What does myoglobin help to do?
Unload oxygen into muscles that require oxygen
41
Why are red muscles red?
Because they contain lots of myoglobin, which is **iron-rich **and helps deliver oxygen to the muscles during activity
42
Why type of muscles is myoglobin mostly found in?
Muscles that are constantly in use such as those that support posture
43
T/F: Myoglobin is found in all muscles
F
Myoglobin is speacialized. It is NOT found in all muscles but are found in most muscles that are constantly in use
44
This compound reversibly binds to oxygen
Iron
45
T/F: All forms of hemoglobin (myoglobin, fetal, and adult) contain iron
T
46
The ____________ found in myoglobin may be one of the reasons that eating red meat is sometimes considered unhealthy. Dr. Schmidt disagrees.
iron
47
Why is the majority of oxygen bound to Hb?
Oxygen is poorly soluble in the blood so it preferes to bind to hemoglobin rather than stay in the dissolved state
48
What is the formula for O2 content in the blood?
O2 content = [(O2 carrying capacity of Hb) x (% saturation)] + (Dissolved O2)
49
What is the normal O2 carrying capacity of Hb at 100% saturation?
20.1 mL O2 per dL
50
What is the normal dissolved O2 in the blood?
0.3 mL O2 per dL
51
What is the normal O2 content?
20.4 mL O2 per dL
52
If 50% of Hb's binding sites are occupied with CO, how many binding sites are available for O2 to bind to?
How does this affect oxygen saturation?
2 binding sites
Oxygen saturation will be 50%
53
If a patient is anemic they have less _______________
hemoglobin _______________
54
T/F: An anemic patient has less Hb and 100% of the Hb binding sites are occupied so the oxygen carrying capacity will remain at 100%
An anemic patient has less Hb and 100% of the Hb binding sites are occupied so the oxygen carrying capacity will **be lower**
There is less oxygen being carried even though Hb is fully saturated because there just isn't enough Hb.
55
Carbon monoxide (CO) is very dangerous because it ________________
displaces oxygen from Hb
56
T/F: CO binds tightly to Hb, making it hard to release without intervention
T
57
What is the treatment for CO poisoning?
Adminstering 100% O2 to help displace the CO from Hb and as the COs fall off the Hb, they are replaced with O2
58
T/F: CO stays stuck to Hb indefinitely
F
59
An increased infinity of oxygen would cause a ____ shift in the oxyhemoglobin dissociation curve.
leftward
60
What does the red arrow indicate?
This is a lower plateau which indicates that fewer oxygen molecules can be carried whth Hb is occupied by CO
61
If there is a **decrease** in Hb's affinity for oxygen, the curve shifts to the _____________
Right
Hint: **Dr**. ILL
62
If there is a **increase** in Hb's affinity for oxygen, the curve shifts to the _
Left
Hint: Dr. **IL**L
63
What are the two problems that carbon monoxide poisoning cuases?
1. Displaces oxygen from Hb
2. When CO binds to even one site on Hb it increases Hb's affinity for O2 so much that it prevents Jb from unloading the O2 into the tissues, causing a leftward shift in the oxyhemoglobin dissociation graph
64
What dose the orange circle indicate?
Increased affinity for oxygen d/t CO poisoning
65
In a healthy person, the typical arterial oxygen saturation (SaO2) is around ___________
97.4%
66
T/F: The actual ideal arterial oxygen saturation might be slightly lower than 100%, but Dr. Schimidt will use 100% for simplicity.
T
67
What is the normal O2 carrying capacity of Hb at 97.4% arterial saturation?
19.58 mL O2 per dL
(20.1) x (97.45%)
68
The saturation in venous blood is generally ________ than in arterial blood.
lower
69
In a healthy person, the typical venous oxygen saturation (SvO2) is around ___________
75% or 3/4
70
What is the normal O2 carrying capacity of Hb at 75% venous saturation?
15.08 mL O2 per dL
**Dr. Schmidt said to round to 15 for ease
**
(20.1) x (75%)
71
T/F: All circulation beds follow the pattern were arterial blood saturation at 100% and venous blood saturation at about 75%
72
How saturated is venous Hb?
75% OR 3/4
73
How saturated arterial is Hb?
Actual = 97.4%
Simplicity Purposes = 100&
74
How many mLs of O2 per dL does arterial blood have or was is arterial blood oxygen?
19.58 is the actual and it's rounded to 20 mL O2 per dL
75
How many mLs of O2 per dL does venous blood have or what is venous blood oxygen?
15.08 is the actual and it's rounded to 15 mL O2 per dL
76
What is the normal O2 consumption for an average, healthy adult?
250 mL O2 per minute
77
How much oxygen carried by Hb falls off between arterial blood and venous blood?
5 mL O2 per dL
78
What percentage of all circulation beds follow the pattern of arterial blood having 20 mL O2 per dL and venous blood having 15 mL O2 per dL
What are the two exceptions that break this pattern
97%
3/25 YUJA 38:35
the heart and the coronary arteries (the heart uses a lot of energy)
79
The Hb that goes into the coronary circulation is ________ with oxygen.
very saturated (97.4% actual, 100% for Schmidt)
80
Blood exits the coronary cirulcation via the __________
coronary sinus
81
The blood exiting the coronary circulation via the ________ typically has a Hb saturation of ____ which is really ____ compared to other circulatory beds which have a saturation of ______
coronary sinus; 25%; low; 75%
82
Why does blood exiting the coronary sinus typically have a Hb saturation of 25%?
As Hb moves throuh the coronary circulation, the heart is incredibly efficient at pulling out 75% or 3/4 of delivered oxygen, this dropping Hb saturation to 25% in the coronary sinus
83
What is a **PRO** of the hearts efficiency in extracting 75% of oxygen from Hb cells?
This cuts down on the amount of coronary perfusion that is needed
84
What is a **CON** of the hearts efficiency in extracting 75% of oxygen from Hb cells?
The heart is very efficient so it extracts what it uses up. This leaves little room for error. If something goes wrong (ex: coronary blockage) there is left over oxygen to compensate.
There is no saftey net to get additional oxygen to heart tissue incase of inadequate perfusion.
the heart must have collateral circulation to compensate
85
At what PO2 level does fetal Hb become 100% saturated?
30 mmHg
86
At what PO2 level does adult Hb become 100% saturated?
100 mmHg
87
If a molecule has a **higher** affinity for oxygen, it will achieve a high Hb saturation at ________ PO2
lower
88
If a molecule has a **lower** affinity for oxygen, it will achieve a high Hb saturation at ________ PO2
higher
89
In reality, the venous oxygen Hb saturation % is a little bit less than 75%. Why is this?
In venous circulation, there is more CO2 and more protons H+ which makes venous blood more acidic. This lowers Hb's affinity for oxygen making it a bit less than 75%
90
PCO2 is 80 mmHg (acidotic). How does the oxygen dissociation curve shift and why?
RIGHT shift
As blood moves through more heavily concentrated areas, it wants to unload more oxygen because the Hb isn't holding the oxygen as tightly because the tissues need it
91
What is another to say volumes %?
Oxygen content
92
PCO2 is 20 mmHg (alkalotic). How does the oxygen dissociation curve shift and why?
LEFT shift
There be not much happening at that tissue so so oxygen is less prone to falling off because the tissues don't need it
93
The only oxygen that is available to the tissues (tissues w/o myoglobin) is oxygen in the ________ form
dissovled form (NOT bound)
94
________ is the only type of hemoglobin that can pull oxygen off tissues.
Myoglobin
95
T/F: All types of Hb can pull oxygen off tissues
F
**Myoglobin** is the only type of hemoglobin that can pull oxygen off tissues.
96
Blood entering a hypercapnic/acidic/metabolically active environment would cause a ________ shift in the oxygen dissociation curve to support oxygen off-loading.
RIGHT
97
2, 3, BPG is a by-product of ________ in the body.
metabolism
98
The Bohr effect relates to oxygen ________ in the tissue
unloading
99
An alkalotic environment would ________ Hb's affinity for oxygen.
INCREASE
100
What does 2, 3 BPG stand for? What's acid name?
2, 3 **BI**-phospho-glycerate
**BI**-phospho-glycer-ic acid
101
What does 2, 3 DPG stand for? What it's acid name?
2, 3 **DI**-phospho-glycerate
**DI**-phospho-glycer-ic acid
102
Low metabolic activity would result in ________ levels of 2, 3 BPG.
LOW
103
The nomenclature -ate can be used to describe an _____________
acid
104
If there is **MORE** 2, 3 BPG, how would the oxygen diss. curve shift?
to the right (high metabolic activity)
105
If there is **LESS** 2, 3 BPG, how would the oxygen diss. curve shift?
to the left (less metabolic activity)
106
____ temperatures make oxygen fall off slower, O2 will hang onto Hb tighter.
Colder
107
____ temperatures make oxygen fall off faster
Warmer
108
What are the 4 factors that contribute to the Bohr affect on the oxygen diss. curve?
1. PCO2
2. pH
3. 2,3-BPG
4. Temperature
109
1. Decreased pH
2. Increased PCO2
3. Increased 2,3-BPG
4. Increased Temperature
How will the oxygen diss. curve shift?
To the right
110
1. Increased pH
2. Decreased PCO2
3. Decreased 2,3-BPG
4. Decreased Temperature
How will the oxygen diss. curve shift?
to the left
111
If there is no 2,3 BPG it will be ________ to offload oxygen
harder
112
What is the normal temperature in the lungs?
37 degrees
113
If temp < 37 degrees in the **lungs**, this would help with oxygen ________ in the tissues
loading
114
**Offloading O₂** (such as when oxygen is being delivered to tissues) shifts the oxygen-hemoglobin dissociation curve to the ________ making hemoglobin more likely to release oxygen.
RIGHT
Hint: **OFFeR**
115
If temp > 37 degrees in the **periphery**, this would help with oxygen ________ in the tissues
unloading
116
**Onloading O₂** shifts the oxygen-hemoglobin dissociation curve to the ________ making hemoglobin more likely to bind oxygen.
LEFT
Hint: **LOaN**
117
In reality what is a normal venous hemoglobin saturation % in a completely healthy patient?
~70%
He previous said it was 75% (seriously...)
118
What is a condition that could cause venous Hb saturation to be higher than normal?
If the venous blood travels through tissue that isn't extracting a lot of oxygen because that tissue's metabolic rate is low, this will bring venous Hb saturation up.
119
________ refers to the partial pressure of oxygen (PO2) that is required to bring the Hb oxygen saturation level to 50%.
Under normal conditions this would be ________ mmHg
P50; 26.5 mmHg
120
If the oxygen-hemoglobin dissociation curve shifts to the **LEFT**, P50 numbers would ________
Decrease
121
If the oxygen-hemoglobin dissociation curve shifts to the **RIGHT**, P50 numbers would ________
Increase
122
What are the three forms of how CO₂ is carried around the blood?
1. Dissolved CO₂
2. Carbamino compounds
3. Bicarbonate
123
What percentage does HCO₃⁻ make up in the total amount of CO₂ floating in the **arterial** system?
90%
124
What percentage do carbamino compounds CO₂ make up in total amount of CO₂ floating in the **arterial** system?
5%
125
What percentage does dissolved CO₂ make total amount of CO₂ floating in the **arterial** system?
5%
126
A carbamino compounds consistents of what 4 things?
1. Nitrogen
2. Two Hydrogen
3. R Group
127
What drops off from the terminal amine group to make a carbamino group when CO₂ is added?
a hydrogen
128
What is the formula to calculate the amount of dissovled CO₂ in a system?
Amount of Diss. CO₂ in Sample = (Solubility of CO₂) X (Partial Pressure of CO₂ in soln)
129
For every deciliter (dL) of solution (likely blood plasma), ________ mL of oxygen dissolves per mmHg of partial pressure of PCO2
0.06
130
What is the dissolved CO₂ content if PVO2 = 40 mmHg per dL of solution?
(0.06) x 40 = 2.4 mL of CO₂ per dL
131
What is the solubility coefficent for dissolving CO₂ gas in a solution?
0.06 mL of CO₂ per mmHg per dL
132
If there is more CO₂ in solution, there are ________ carbamino compounds
more
133
Carbonic acid is unstable. What can it fall apart to make?
1. Water & CO₂
2. Bicarb and H+
CO₂ + H₂O ⇌ H₂CO₃ ⇌ H⁺ + HCO₃⁻
134
What is the chemical equation for the blood buffer system?
CO₂ + H₂O ⇌ H₂CO₃ ⇌ H⁺ + HCO₃⁻
135
Where the blood buffer chemical equation goes left (makes more H₂CO₃ that breaks down into more CO₂ and water) or right (makes more HCO₃⁻) depends on what?
How much CO₂ is in the environment
136
What is the main way that CO₂ is transported through the body?
As bicarbonate
HCO₃⁻
137
What percentage does HCO₃⁻ make up in the total amount of CO₂ floating in the **venous** system?
60%
138
What percentage do carbamino compounds CO₂ make up in total amount of CO₂ floating in the **venous** system?
30%
139
What percentage does dissolved CO₂ make total amount of CO₂ floating in the **venous** system?
10%
140
At a PCO₂ of 45 mmHg, in a 70% saturated oxyhemobglobin sample, what the average total **venous** CO₂ content?
52.5 mL CO₂/dL
141
At a PCO₂ of 40 mmHg, in a 70% saturated oxyhemobglobin sample, what the average total **arterial** CO₂ content?
48 mL CO₂/dl
142
# CO₂ Dissociation Curve
How could the shift from arterial curve to the venous curve on the CO₂ dissociation curve be described?
A shift up or to the left
143
# CO₂ Dissociation Curve
How could the shift from venous curve to the arterial curve on the CO₂ dissociation curve be described?
A shift down or to the right
144
# CO₂ Dissociation Curve
What is the cause of the difference between the arterial and the venous curve?
Hb oxygenation
