Ex phys chapter 7 Flashcards
1
Q
The purpose of the respiratory system is to
A
carry O2 to and remove CO2 from all body tissues
2
Q
The 4 processes that carry out the respiratory process are
A
- Pulmonary ventilation (external respiration)
- Pulmonary diffusion (external respiration)
- Transport of gases via blood
- Capillary diffusion (internal respiration)
3
Q
Pulmonary ventilation
A
is the process of moving air into and out of lungs (transport zone, and exchange zone)
4
Q
At rest, air drawn into lungs through nose, but:
A
through mouth when demand exceeds
5
Q
Nose/mouth → pharynx →
A
larynx → trachea → bronchial tree → alveoli
6
Q
Lungs suspended by pleural sacs
- Parietal pleura lines ______wall
- Visceral (pulmonary) pleura attaches to lungs
- Lungs take size and shape of rib cage
A
thoracic
7
Q
Anatomy of lung, pleural sacs, diaphragm, and rib cage determines:
A
airflow into and out of lungs
- Inspiration
- Expiration
8
Q
inspiration is a ___ process.
A
active
9
Q
Involved muscles in inspiration::
- _____ ______ move rib cage (up & out) and sternum (up & forward)
- ________ flattens down toward the abdomen
A
- External intercostals
- Diaphragm
10
Q
Inspiration:
-Expands thoracic cavity in ____ dimensions
- Expands volume inside ______ cavity
- Expands volume inside lungs
A
- three
- thoracic
11
Q
Lung volume ↑, intrapulmonary pressure ↓
- ______ law regarding pressure versus volume
- At constant temperature, pressure and volume inversely ______
A
- Boyle’s
- proportional
12
Q
during respiration Air passively rushes in due to
A
pressure difference
13
Q
Forced breathing uses additional muscles such as
____ _____ &_______ that
Raise ribs even farther
A
Scalenes, sternocleidomastoid, pectorals
14
Q
expiration is usually a ____ process
A
passive
15
Q
expiration: Usually passive process
- ______ muscles relax
- ____ ____ ↓, intrapulmonary pressure ↑
- Air forced out of lungs
A
- Inspiratory
- lung volume
16
Q
when expiration is an active process (forced breathing):
- ____ ___ pull ribs down
- Also, ____ ____ & ____ ____
- Abdominal muscles force diaphragm back up
A
- Internal intercostals
- latissimus dorsi, quadratus lumborum
17
Q
Respiratory pump
- Changes in intra-abdominal, intrathoracic pressure promote : ____
- Pressure ↑ → venous compression/squeezing
- Pressure ↓ → venous filling
A
venous return to heart
18
Q
Milking action from changing pressures assists :
A
right atrial filling (respiratory pump)
19
Q
pulmonary volumes:
Measured using
A
spirometry
20
Q
pulmonary volumes: Measured using spirometry
- Lung volumes, capacities, flow rates
- _______– air entering & leaving the lungs
- _______ – greatest air volume expired
- _______ – air remained in lungs
- ________– sum of VC and RV
A
- Tidal volume
- Vital capacity (VC)
- Residual volume (RV)
- Total lung capacity (TLC)
21
Q
spirometry
A
Diagnostic tool for respiratory disease
22
Q
pulmonary diffusion is:
A
Gas exchange between alveoli and capillaries
23
Q
Gas exchange between alveoli and capillaries
- Inspired air path: bronchial tree → arrives at _____
- Blood path: right ventricle → _____ → pulmonary arteries → pulmonary capillaries
- Capillaries surround alveoli
A
- alveoli
- pulmonary trunk
24
Q
Pulmonary Diffusion Serves two major functions:
A
- Replenishes blood oxygen supply
- Removes carbon dioxide from blood
25
At rest, lungs receive ______ blood / min
~4 to 6 L
26
RV cardiac output = LV cardiac output
| Lung blood flow = _______
systemic blood flow
27
Low pressure circulation
- Lung MAP = ___ mmHg versus aortic MAP = ___ mmHg
- Small pressure gradient (15 mmHg to 5 mmHg)
- Resistance much lower due to _______
- 15
- 95
- thinner vessel walls
28
Respiratory Membrane is also called
alveolar-capillary membrane
29
respiratory membrane Also called alveolar-capillary membrane is made up of
Alveolar wall
Capillary wall
Respective basement membranes
30
Respiratory membrane: Surface across which gases are exchanged:
-Very thin: _ to _ μm
-Large surface area: ___ alveoli in close proximity to blood
Maximizes gas exchange
- 0.5-4
| - 300 MILLION
31
Pulmonary Diffusion:
Partial Pressures of Gases
Air=
79.04% N2 + 20.93% O2 + 0.03% CO2
32
Total air P:
atmospheric pressure
33
Individual P:
partial pressures
34
Standard atmospheric P =
760 mmHg
35
Dalton’s Law: total air P = PN2 + PO2 + PCO2
PN2 + PO2 + PCO2
36
```
PN2 = 760 x 79.04% = ___
PO2 = 760 x 20.93% = ______
PCO2 = 760 x 0.04% = ______
```
- 600.7 mmHg
- 159.1 mmHg
- 0.2 mmHg
37
Henry’s Law:
gases dissolve in liquids in proportion to partial P
Also depends on specific fluid medium, temperature
Solubility in blood constant at given temperature
38
Partial P gradient most important factor for
determining gas exchange
39
- Partial P gradient drives gas ____
| - Without gradient, gases in equilibrium, no ____-
- Diffusion
| - Diffusion
40
Atmospheric PO2 =
159 mmHg
41
Alveolar PO2 =
105 mmHg
42
Pulmonary artery PO2 =
40 mmHg
43
PO2 gradient across respiratory membrane: ____
| Results in pulmonary vein PO2 ~100 mmHg
65 mmHg (105 mmHg – 40 mmHg)
44
Fick’s Law:
rate of diffusion proportional to surface area and partial pressure gas gradient
45
Ficks Law:
PO2 gradient: ___ mmHg
PCO2 gradient: __mmHg
- 65
| - 6
46
Diffusion constant influences diffusion rate:
- Constant different for each gas
- CO2 _____ diffusion constant than O2
- CO2 diffuses _____ despite lower gradient
- Lower
| - easily
47
O2 diffusion capacity
-O2 volume diffused per minute per 1 mmHg of gradient
-Note: gradient calculated from capillary mean PO2,
≈
11 mmHg
48
Resting O2 diffusion capacity
- 21 mL O2/min/mmHg of gradient
| - 231 mL O2/min for 11 mmHg gradient
49
Maximal exercise O2 diffusion capacity
- Venous O2 ↓↓ → PO2 bigger gradient
| - Diffusion capacity ↑ by three times resting rate
50
At rest, O2 diffusion capacity limited due to incomplete
lung perfusion
51
At rest, O2 diffusion capacity limited due to incomplete lung perfusion
- Only bottom ___ of lung perfused with blood
- Top ____ lung surface area → poor gas exchange
- 1/3
| - 2/3
52
During exercise, O2 diffusion capacity ↑ due to more even _____
-lung perfusion
53
During exercise, O2 diffusion capacity ↑ due to more even lung perfusion
- Systemic blood pressure ↑ _____ top 2/3 perfusion
- Gas exchange over full lung surface area
-opens
54
Pulmonary artery PCO2
~46 mmHg
55
Alveolar PCO2 ~
40 mmHg
56
6 mmHg PCO2 gradient permits diffusion
- CO2 diffusion constant ___ times greater than O2
- Allows diffusion despite lower gradient
20
57
Oxygen Transport in Blood
Can carry ___ mL O2/___ mL blood
~__ L O2/__ L blood
>__% bound to hemoglobin (Hb) in red blood cells
- 20 & 100
- 1 & 5
- 98%
- 2%
58
O2 + Hb:
oxyhemoglobin
59
Hb alone:
deoxyhemoglobin
60
High PO2 (i.e., in lungs)
- Loading portion of O2-Hb dissociation curve
- ____ change in Hb saturation per mmHg change in PO2
Small
61
Low PO2 (i.e., in body tissues)
- Unloading portion of O2-Hb dissociation curve
- ____ change in Hb saturation per mmHg change in PO2
large
62
Blood pH
- More acidic → O2-Hb curve shifts to ____
- Bohr effect
- More O2 unloaded at acidic exercising Muscle
- Right
| - Muscle
63
Blood temperature
- Warmer → O2-Hb curve shifts to ___
- Promotes _____ O2 unloading during exercise
- Right
| - tissue
64
Maximum amount of O2 blood can carry
- Based on Hb content (___-___ g Hb/___ mL blood)
- Hb __ to __% saturated at rest (0.75 s transit time)
- Lower saturation with exercise (shorter transit time)
- (12-18 g Hb/100 mL blood)
- Hb 98 to 99% saturated at rest (0.75 s transit time)
- Lower saturation with exercise (shorter transit time)
65
Blood Oxygen-Carrying Capacity Depends on ___ ___ ____
1 g Hb binds ____ mL O2
Blood capacity: ___ to __ mL O2/100 mL blood
Anemia → ↓ Hb content → ↓ O2 capacity
- blood Hb content
- 1.34
- 16 to 24
66
Carbon Dioxide Transport in Blood is released as ___ from cells
waste
67
Co2 is carried in blood three ways:
- As bicarbonate ions
- Dissolved in plasma
- Bound to Hb (carbaminohemoglobin)
68
Bicarbonate Ion Transports __ to __% of CO2 in blood to lungs
60 to 70%
69
Carbon Dioxide Transport:
Bicarbonate Ion
-CO2 + water form carbonic acid (H2CO3)
- Occurs in ______
- Catalyzed by:
- Red blood cells
| - carbonic anhydrase
70
Carbonic acid dissociates into bicarbonate
CO2 + H2O → H2CO3 → HCO3- + H+
H+ binds to Hb (buffer), triggers _____
Bicarbonate ion diffuses from red blood cells into __-
- Bohr effect
| - plasma
71
Carbon Dioxide Transport:
Dissolved Carbon Dioxide:
-__ to ___% of CO2 dissolved in plasma
-When PCO2 low (in lungs), CO2 comes out of solution, diffuses out into _____
- 7 to 10
| - alveoli
72
Carbon Dioxide Transport:
Carbaminohemoglobin:
___ to ___% of CO2 transported bound to Hb
20-33
73
```
Carbon Dioxide Transport:
Carbaminohemoglobin:
>Does not compete with ______
-O2 binds to heme portion of Hb
-CO2 binds to protein (-globin) portion of Hb
```
O2-Hb binding
74
```
Carbon Dioxide Transport:
Carbaminohemoglobin:
Hb state, PCO2 affect CO2-Hb _____
Deoxyhemoglobin binds ___ easier versus oxyhemoglobin
– ↑ PCO2 → easier CO2-Hb binding
– ↓ PCO2 → easier CO2-Hb dissociation
```
- binding
| - Co2
75
Bicarbonate Ion: Transports __- to __% of CO2 in blood to lungs
60 to 70%
76
CO2 + water form _______ (H2CO3)
Occurs in ______
Catalyzed by carbonic anhydrase
- carbonic acid
| - Red blood cells
77
Carbonic acid dissociates into bicarbonate
- CO2 + H2O → H2CO3 → HCO3- + H+
- H+ binds to Hb (buffer), triggers ____ effect
- Bicarbonate ion diffuses from red blood cells into _____
- Bohr
| - plasma
78
during carbon dioxide transport __ to __% of CO2 dissolved in plasma
7 to 10
79
When PCO2 low (in lungs), CO2 comes out of solution, diffuses into ___
alveoli to be exhaled
80
during Carbaminohemoglobin
| 20 to 33% of CO2 transported bound to ___
HB
81
Carbaminohemoglobin does not compete with ____
- O2 binds to heme portion of Hb
- CO2 binds to protein (-globin) portion of Hb
-O2-Hb binding
O2 binds to heme portion of Hb
CO2 binds to protein (-globin) portion of Hb
