Final Exam Respiratory 4-6 Flashcards
(106 cards)
1
Q
Blood entering the alveolar capillary from the small pulmonary arteries
A
Mixed venous blood
2
Q
What percentage of O2 is dissolved in blood?
A
2%
3
Q
What percentage of O2 is bound to hemoglobin?
A
98%
4
Q
The only form of O2 that produces a partial pressure, which drives O2 diffusion
A
Dissolved O2
5
Q
What do the subunits of hemoglobin contain?
A
A Heme molecule
An 2 Alpha and 2 Beta polypeptide globulin chains
6
Q
What produces the heme molecule on hemoglobin?
A
mitochondria
7
Q
What produces the alpha and beta chains on a heme molecule?
A
Ribosomes
8
Q
What is the difference between an adult hemoglobin and fetal hemoglobin?
A
Adult: contains 2 alpha and 2 beta chains
Fetal: contains 2 alpha and 2 gamma chains
9
Q
Why does fetal hemoglobin have gamma chains instead of beta?
A
Higher affinity for O2 to facilitate O2 movement from mother to fetus
10
Q
What would happen if there was no globin?
A
oxygen would oxidize the ferrous iron to ferric iron
11
Q
Enzyme located inside of RBCs that helps keep iron in its reduced state
A
Methemoglobin reductase
12
Q
name for oxygenated hemoglobin
A
oxyhemoglobin
13
Q
Name for deoxygenated hemoglobin
A
Deoxyhemoglobin
14
Q
for the subunits to bind O2, iron in the heme molecule must be in the Ferrous/Ferric State?
A
Ferrous
15
Q
T/F. Methemoglobin does not bind to O2
A
T
16
Q
T/F. in sickle cell disease both the alpha and beta subunits are abnormal.
A
F. Alpha is normal, Beta is abnormal
17
Q
What is positive cooperativity?
A
Binding of the first molecule of O2 to a heme group inc. the affinity for the second molecule and so on. . .
18
Q
What is P50?
A
Po2 at which hemoglobin is 50% saturated
2 heme groups are bound to O2
19
Q
An inc. in P50 reflects a inc/dec in affinity
A
Dec.
20
Q
A dec. in P50 relfects a inc/dec in affinity
A
Inc.
21
Q
At lower values of PO2, affinity for O2 is Higher/Lower
A
Lower
22
Q
At Higher values of PO2, affinity for O2 is Higher/Lower
A
Higher
23
Q
Do High values of PO2 facilitate loading or unloading of O2 in the lungs?
A
Loading
24
Q
Do Low values of PO2 facilitate loading or unloading of O2 in the tissues?
A
Unloading
25
what 4 factors will cause the oxyhemoglobin dissociation curve to shift to the left?
1. Higher Hb-O2 affinity
2. Lower CO2
3. Higher pH
4. Lower Temp.
26
What 4 factors will cause the oxyhemoglobin dissociation curve to shift to the right?
1. Reduced Hb-O2 affinity
2. Higher CO2
3. Lower pH
4. Higher temp.
27
What are the 3 ways CO2 is carried in blood?
1. Dissolved CO2
2. Carbaminohemoglobin
3. Bicarbonate
28
What is the most important way to transport CO2 in the blood?
Bicarbonate (HCO3-)
29
T/F. The reaction between CO2 and water in the blood to form H2CO3 happens quickly in plasma and slowly inside RBC?
F. Slow in plasma, Quick in RBC
30
The reaction where dissolved CO2 in plasma reacts with water to form carbonic Acid (H2CO3)
Hydration Rxn
31
Enzyme that is abundant w/i RBCs and catalyzes the hydration reaction
Carbonic Anhydrase
32
T/F. PO2 and PCO2 increases greatly during exercise?
F. Hardly altered
33
What are the 4 components in the control of breathing.
1. control centers in the brainstem
2. chemoreceptors for O2 and CO2
3. mechanoreceptors in the lungs and joints
4. resp. muscles whose acitvity is directed by brain stem.
34
The respiratory center is composed by several groups of neurons located where?
pons and medulla
35
What are the 3 major centers of the brain stem control of respiration?
1. dorsal respiratory group
2. ventral respiratory group
3. the pneumotaxic center
36
What two brain stem control centers are in the medulla?
dorsal and ventral resp. group
37
What brain stem control center is in the pons?
pneumotaxic center
38
Where are most neurons located within the dorsal resp. group?
Nucleous of the tractus solarius (NTS)
39
The sensory termination of both the vagal and glossopharyngeal nerves
NTS
40
The vagal and glossopharyngeal nerves send sensory signals to the respiratory center through the NTS from which 3 places?
1. peripheral receptors
2. baroreceptors
3. receptors in lungs
41
The basic rhythm of resp. is generated mainly in the ____ group of neurons
Dorsal resp.
42
The ____ causes a steady inc. in the volume of the lungs during inspiration, rather than inspiratory gasps
ramp signal
43
What are the 2 controls of the inspiratory ramp:
1. control of the rate of inc. of the ramp signal
| 2. control of the limiting point at which the ramp suddenly ceases
44
Why do we have the control of the rate of inc. of the ramp signal?
So that during heavy resp. the ramp inc. rapidly and therefore fills the lungs rapidly
45
why do we have to control the limiting point at which the ramp suddenly ceases
controls the rate of resp.
46
the earlier the ramp ceases, the _longer/shorter_ the duration of inspiration/expiration
Shorter
47
Where is the pneumotaxic center located?
Pons
48
what is the primary effect of the pneumotaxic center
control the "switch-off" point of the inspiratory ramp
limits inspiration, controlling the duration of the filling phase of lung cycle
49
This area operates as an overdrive mech. when high levels of pulmonary ventilation are required
ventral resp. group
50
T/F. the neurons of the ventral resp. are activated during normal quiet respiration?
F. inactive during quiet resp.
51
what are the 3 most important sensory info. arriving at the brain stem
PaO2, PaCO2, pH
52
receptors in brain stem that are important for minute to minute conrrol of breathing and communicate with the inspiratory center
chemoreceptors
53
What are the chemoreceptors in the brain stem sensitive to?
Inc in pCO2
54
T/F. the BBB is permeable to CO2 but not HCO3-, or H+
T
55
A Dec. in pH signals the inspiratory center to _inc/dec_ breathing rate?
Inc
56
Where are peripheral chemoreceptors located?
carotid and aortic bodies
57
What are peripheral chemoreceptors sensitive to?
Dec. in PO2
58
glandular-like cells located in the carotid and aortic bodies?
Glomus cell
59
What are the 3 steps of glomus cell stimulation
1. when PO2 dec below 60mmHg, k+ channels close causing depolarization
2. Voltage gated Ca channels open and stimulates transmitter release
3. transmitter activates afferent fibers to sen signals to CNS and stimulates resp.
60
What are the 2 transmitters used in the stimulation of glomus cells
1. ATP
| 2. AcH
61
With the dec. in PO2, the firing rate of the sensory neurons _inc/dec_
Inc.
62
Why are peripheral chemoreceptors particularly sensitive to a PO2 range b/t 60 and 30 mmHg?
this is the range in which hemoglobin saturation O2 dec.
63
Dec. in PO2 causes an _inc/dec_ in breathing rate?
inc.
64
if you Inc. PCO2; you _inc/dec_ alveolar vent.?
Inc
65
Dec. PCO2 = inc/dec alveolar vent?
dec
66
Inc pH = _inc/dec_ alveolar vent
dec
67
Dec. pH = _inc/dec_ alveolar vent
inc
68
Inc PO2 = _inc/dec_ alveolar vent?
dec
69
Dec. PO2 = _inc/dec_ alveolar vent
inc
70
Mechanoreceptors located in the smooth muscle of airways that are stimulated by distension of lungs
Lung Streach receptors
71
What is the Hering-Breuer reflex?
When lung streach receptors are stimulated they initiate this reflex to dec. in breathing rate
72
Reflex that dec. breathing rate by prolonging expiratory time
Hering-Breuer reflex
73
Mechanoreceptors located in the joints and muscles, that detect the movement of limbs and instruct the inspiratory center to inc. breathing rate
joint and muscle receptors
74
receptors for noxious chemicals and particles are located b/t epithelial cells lining the airways
irritant receptors
75
Information from these receptors travels to medulla and causes a reflex constriction of bronchial smooth muscle and an inc. in breathing rate
irritant receptors
76
T/F. During moderate exercise there is no change in arterial PO2, PCO2, or pH
T
77
During moderate exercise there is a dec. in venous PCO2
F. Inc
78
T/F. Ascent to high altitude can cause hypoxemia
T
79
What is the most significant short-term response to high altitude?
Hyperventilation
80
T/F. hyperventilation leads to respiratory acidosis
F. alkalosis (inc. in pH)
81
What are the 3 long term adjustments to hypoxia?
1. prodution of more erythrocytes
2. dec. affinity of hemoglobin for O2
3. inc. capillary density in muscle
82
T/F hypoxic vasoconstriction can induce heart failure?
T
83
What are the 3 non respiratory functions of the lungs?
1. defense mechanisms
2. Pulmonary fluid exchange
3. metabolic functions
84
What are the 2 defense mechanisms of the lungs?
1. nonspecific/innate immunity
| 2. specific defense/ adaptive immunity
85
type of defense mech. that offers immediate protection against many inhaled substances
nonspecific/innate
86
What are the 4 ways of the innate immune response in the lungs?
1. mucociliary system
2. cough
3. resident phagocytic cells in alveoli
4. TLRs on surface of cells
87
Type of defense that involves the immune system and is directed against specific injurious agents
Specific/adaptive
88
Which type of defense has an immune memory?
Adaptive
89
What are the 3 ways of particle deposition in the mucocillary system?
1. Impaction
2. sedimentation
3. diffusion
90
How do large particles contact the airways?
impaction
91
Where does impaction typically occur?
where airway direction changes
92
What is accumulated near sites of inertial impaction?
accumulations of lymphoid tissue
93
How do small to medium sized particles contact the airways?
Sedimentation/diffusion
94
Where does sedimentation and diffusion typically occur?
where airflow rates diminish deeper in lungs
95
What are the 2 layers of the mucociliary system?
1. Watery layer (SOL)
| 2. mucus layer (GEL)
96
What are the 3 sites where mucus originates from?
1. bronchioles
2. larger airways
3. bronchial mucosa
97
What type of cells in bronchioles produce mucus
clara cells
98
what type of cells in the large airways produce mucus?
Goblet cells
99
What type of cells in the bronchial mucosa produce mucus?
Bronchial glands
100
Normal airway epithelia regulate the rates of ____ absorption and ____ secretion to regulate the depth of the mucus layer.
Na; Cl
101
What initiates coughing?
irritant receptors
102
What 2 things can stimulate irritant receptors to induce coughing?
1. mechanical deformation (foreign body)
| 2. Excessive amts. of material on the epithelial surface
103
T/F. cough reflex assists in removing mucus from the more peripheral bronchi and bronchioles
F. does NOT assist
104
Which cell types can produce and release cytokines and chemokines
1. macrophages
2. lymphocytes
3. epithelial cells
4. endothelial cells
5. other
105
Molecules that attract inflammatory cells to the site of injury and provide a means of communication b/t cells
Cytokines and chemokines
106
Inflammation of the Pleura
pleuritis
