Respiratory System (Pt. 2) Flashcards
(212 cards)
1
Q
What law governs pressure changes during breathing?
A
Boyle’s Law - the volume of a gas varies inversely with its pressure
2
Q
What pressure is needed for air to move into lungs?
A
Pressure inside alveoli must be less than atmospheric pressure
3
Q
What is atmospheric pressure at sea level?
A
760 mmHg
4
Q
How does Boyle’s Law apply to breathing?
A
- Increasing lung volume decreases air pressure
- Decreasing lung volume increases air pressure
5
Q
What happens when intercostal muscles are relaxed (at rest)?
A
- Lung size remains unchanged
Air pressure equals atmospheric pressure
No airflow occurs
6
Q
What happens when intercostal muscles contract?
A
- Chest cavity expands
Lung size increases
Pressure drops below atmospheric pressure
Air flows in
7
Q
What drives air movement?
A
Air moves from areas of higher pressure to areas of lower pressure
8
Q
How is inhalation achieved?
A
By expanding the lungs, which lowers internal pressure below atmospheric pressure
9
Q
What creates the pressure difference necessary for breathing?
A
Changes in lung size driven by intercostal muscle movement
10
Q
A
11
Q
What is the basic principle of Boyle’s Law?
A
As volume increases, pressure decreases (and vice versa) - they are inversely proportional
12
Q
What happens to gas pressure when container size increases?
A
Pressure decreases because molecules have more space to occupy
13
Q
What happens to gas pressure when container size decreases?
A
Pressure increases because molecules have less space to occupy
14
Q
During inhalation, what happens to the chest cavity?
A
Chest cavity: Gets BIGGER
Lung pressure: Gets LOWER
Air movement: Flows IN from higher pressure outside
15
Q
During exhalation, what happens to the chest cavity?
A
Chest cavity: Gets SMALLER
Lung pressure: Gets HIGHER
Air movement: Flows OUT to lower pressure outside
16
Q
What causes air to move in and out of lungs?
A
Pressure differences created by changing lung volume
17
Q
What drives the pressure changes in lungs?
A
Changes in chest cavity size caused by respiratory muscles
18
Q
What initiates breathing?
A
Brain signals sent through phrenic nerves to respiratory muscles
19
Q
What are the main muscles of inspiration?
A
- Diaphragm (main muscle) 2. External intercostals 3. Scalenes and sternocleidomastoid (accessory muscles)
20
Q
What percentage of breathing does the diaphragm handle?
A
75% during quiet breathing
21
Q
How much does the diaphragm typically move?
A
- Normal breathing: 1 cm (500 mL air)
Heavy breathing: up to 10 cm (2-3 liters air)
22
Q
What is the sequence of inhalation?
A
- Muscles stimulated to contract 2. Muscles of inspiration contract 3. Lung pressure decreases 4. Air moves in
23
Q
What happens during exhalation?
A
- Diaphragm and muscles relax
Chest cavity volume decreases, pressure increases, air pushed out
24
Q
What causes air to move into lungs?
A
Pressure difference created when lung volume increases and internal pressure drops below atmospheric pressure
25
What muscles assist in forced exhalation?
Internal intercostals, rectus abdominis, and obliques
26
How much do external intercostals contribute to breathing?
25% of air intake during normal breathing
27
What is the basic structure of the diaphragm?
A dome-shaped muscle separating chest cavity from abdominal cavity
28
What nerve controls the diaphragm?
The phrenic nerve
29
What happens to diaphragm shape during contraction?
It flattens out (becomes less dome-shaped)
30
How far does the diaphragm move during quiet breathing?
1 cm
31
How far does the diaphragm move during heavy breathing?
Up to 10 cm
32
What pressure difference does normal diaphragm movement create?
1-3 mmHg
33
How much air enters lungs during quiet breathing?
About 500 mL
34
What percentage of normal breathing does the diaphragm account for?
75%
35
How does diaphragm movement create airflow?
By increasing chest cavity volume, lowering pressure, causing air to flow in
36
What are the pressure values at rest?
- Atmospheric pressure: 760 mmHg
- Alveolar pressure: 760 mmHg
- Intrapleural pressure: 756 mmHg
37
What happens to pressures during inhalation?
- Alveolar pressure drops to 758 mmHg
## Footnote
Creates pressure gradient for air to flow in
Chest cavity size increases
38
What happens to pressures during exhalation?
- Alveolar pressure increases to 762 mmHg
## Footnote
Creates pressure gradient for air to flow out
Chest cavity returns to original size
39
What muscles are used in deep inhalation?
Scalenes and sternocleidomastoid (in addition to diaphragm and external intercostals)
40
What muscles are used in forced exhalation?
Internal intercostals and abdominal muscles
41
Why is there no airflow at rest?
Because alveolar pressure equals atmospheric pressure (760 mmHg)
42
What creates pressure differences during breathing?
Changes in chest cavity size
43
Why is intrapleural pressure negative?
To help keep lungs expanded against chest wall
44
What are the three main factors affecting pulmonary ventilation?
1. Surface tension
2. Compliance
3. Airway resistance
45
What is surface tension in the lungs?
Inwardly directed force in alveoli that must be overcome during inspiration
46
What is surfactant's role?
Reduces surface tension in alveoli, helping them stay open and making breathing easier
47
What is compliance?
The ease with which lungs and thoracic wall can expand
## Footnote
High compliance = easy expansion
Low compliance = difficult expansion
48
What conditions decrease compliance?
- Scar tissue
- Pulmonary edema
- Reduced surfactant
- Muscle paralysis
49
What is airway resistance?
How much airways resist airflow into and out of lungs
50
What happens to bronchioles during breathing?
- Inhalation: widen, decreasing resistance
- Exhalation: narrow, increasing resistance
51
How does autonomic nervous system affect airways?
- Sympathetic: bronchodilation (widens airways)
- Parasympathetic: bronchoconstriction (narrows airways)
52
What conditions increase airway resistance?
Blockages or narrowing (like in asthma or COPD)
53
What is eupnea?
Normal, quiet breathing with regular rhythm and rate (12-20 breaths/minute)
54
What is apnea?
Temporary stopping of breathing, including:
- Sleep apnea
- Voluntary apnea
- Central apnea
- Obstructive apnea
55
What is dyspnea?
Difficulty breathing/shortness of breath caused by:
- Exercise
- Anxiety
- Heart problems
- Lung conditions
- Obesity
56
What is tachypnea?
Rapid breathing (>20 breaths/minute) caused by:
- Fever
- Anxiety
- Exercise
- Lung conditions
57
What is costal breathing?
- Uses mainly ribcage muscles
- More common in women
- Less efficient
- Chest expands more than abdomen
58
What is diaphragmatic breathing?
- Uses mainly diaphragm
- More common in men
- More efficient
- Abdomen expands more than chest
- Better oxygen exchange
59
Which breathing type is most efficient?
Diaphragmatic (belly) breathing
60
What are benefits of diaphragmatic breathing?
- Better oxygen exchange
- Stress reduction
- More efficient lung capacity use
- Used in meditation
61
What tool measures lung volumes?
Spirometer
62
What are basic lung measurements?
1. Lung volumes (direct measurements) 2. Lung capacities (combinations of volumes)
63
What is normal breathing rate and volume?
- Rate: 12 breaths/minute
Tidal Volume: 500 mL per breath
350 mL reaches respiratory zone
150 mL stays in airways (dead space)
64
What are key lung volumes?
1. Tidal Volume (TV): one normal breath 2. Inspiratory Reserve Volume (IRV): extra inhalation 3. Expiratory Reserve Volume (ERV): extra exhalation 4. Residual Volume (RV): air remaining after max exhalation
65
What factors affect lung volumes?
Gender
Height
Age
Altitude
Body weight
66
What is FEV1?
Forced Expiratory Volume in 1 second (used to diagnose lung conditions)
67
How is breathing shown on spirogram?
- Inhalation: upward movement
Exhalation: downward movement
68
What is minimal volume used for?
Determining if breathing occurred after birth (lungs float in water)
69
What are the four lung capacities?
1. Inspiratory Capacity (IC) = TV + IRV
2. Functional Residual Capacity (FRC) = RV + ERV
3. Vital Capacity (VC) = IRV + TV + ERV
4. Total Lung Capacity (TLC) = VC + RV
70
What is minute ventilation?
Total air moved in/out in one minute
## Footnote
Formula: TV × breathing rate
Normal: 6000 mL/min (12 breaths × 500 mL)
71
What is alveolar ventilation?
Air reaching alveoli per minute
## Footnote
Formula: breathing rate × (TV - dead space)
Normal: 4200 mL/min (12 breaths × 350 mL)
72
What's the dead space volume?
150 mL (air that stays in airways)
73
How much air reaches alveoli per breath?
350 mL out of 500 mL total
74
What's the difference between volumes and capacities?
- Volumes: Basic measurements
Capacities: Combinations of volumes
75
What affects lung volumes?
Gender
Height
Age
Altitude
Body weight
Health
Physical condition
76
What is Dalton's Law?
Each gas in a mixture exerts its own pressure independently
77
What is partial pressure?
Pressure exerted by each individual gas in a mixture
78
What's the total pressure of atmospheric air?
760 mmHg (sum of all partial pressures)
79
How do gases move?
From areas of higher to lower partial pressure (diffusion)
80
How does gas exchange apply to breathing?
O2 moves from lungs to blood when lung pressure is higher
CO2 moves from blood to lungs when blood pressure is higher
81
What drives gas exchange?
Difference in partial pressures between lungs and blood
82
Why is Dalton's Law important for breathing?
Explains how gases move between lungs and blood during respiration
83
What's the main principle Dalton's Law?
Each gas behaves as if it's alone in the mixture
84
What is Henry's Law?
Amount of dissolved gas is proportional to its partial pressure and solubility (at constant temperature)
85
What factors affect gas dissolution?
1. Partial pressure 2. Solubility coefficient 3. Temperature (must be constant)
| Henry's Law
86
How does CO2 compare to O2 in blood solubility?
CO2 is 24 times more soluble than O2
87
What happens when gas pressure increases?
More gas dissolves in the liquid
88
What medical conditions relate to Henry's Law?
Decompression sickness
Nitrogen narcosis
Carbonated beverage behavior
89
What causes decompression sickness?
High pressures underwater increase nitrogen solubility, leading to symptoms similar to intoxication.
90
What is external respiration?
Gas exchange between alveoli and pulmonary capillaries
91
What is internal respiration?
Gas exchange between systemic capillaries and tissue cells
92
How much O2 do tissues use at rest?
25% of available oxygen
93
Why does CO2 exchange happen more efficiently?
CO2 is 24 times more soluble than O2 in blood
94
What is meant by 'independat gas exchange'?
Gases move independently based on their own partial pressure differences, not by direct swapping.
95
How do gases move?
From areas of higher to lower partial pressure for each specific gas.
96
What happens in pulmonary circulation?
- Between heart and lungs
Deoxygenated blood picks up O2
Drops off CO2
Lower pressure, wider vessels.
97
What happens in systemic circulation?
- Between heart and body tissues
Delivers O2 to tissues
Removes CO2
Higher pressure, narrower vessels.
98
What are key differences between circulations?
Pulmonary:
Lower pressure
Wider vessels
Gas exchange in lungs
Systemic:
Higher pressure
Narrower vessels
Gas exchange in tissues.
99
Why don't gases directly swap places?
Each gas moves independently based on its own pressure gradient.
100
What factors affect gas exchange rate?
1. Partial pressure differences 2. Surface area 3. Diffusion distance 4. Molecular weight/solubility 5. Blood flow rate 6. Environmental factors
101
How does pressure difference affect exchange?
Greater difference = faster exchange rate
102
How does surface area affect exchange?
Larger area = faster exchange rate
103
How does diffusion distance affect exchange?
Shorter distance = faster exchange rate
104
How does CO2 compare to O2 in movement rate?
CO2 moves 20 times faster than O2
105
What affects gas exchange in disease?
- Emphysema: reduces surface area
## Footnote
Pulmonary edema: increases diffusion distance
106
How does exercise affect gas exchange?
- Increases pressure differences
- Increases blood flow
- Enhances O2 extraction
107
How does altitude affect gas exchange?
Reduces O2 availability, affecting exchange rate
108
How is oxygen transported in blood?
1.5% dissolved in plasma
98.5% bound to hemoglobin
109
How is carbon dioxide transported?
7% dissolved in plasma
23% bound to hemoglobin (carbaminohemoglobin)
70% as bicarbonate ions (HCO3⁻)
110
What's the main way O2 is transported?
Bound to hemoglobin (98.5%)
111
What's the main way CO2 is transported?
As bicarbonate ions (70%)
112
What's carbaminohemoglobin?
CO2 bound to hemoglobin (23% of CO2 transport)
113
Why are multiple transport methods important?
For efficient:
O2 delivery to tissues
CO2 removal
pH balance
Cellular respiration
114
How does CO2 become bicarbonate?
CO2 + H2O → HCO3⁻ (bicarbonate)
115
How much O2 is dissolved in plasma vs bound to hemoglobin?
- Dissolved in plasma: 1.5%
- Bound to hemoglobin: 98.5%
116
What is affinity?
How strongly one substance binds to another (like hemoglobin binding to oxygen)
117
What affects hemoglobin's affinity for oxygen?
1. Partial pressure of O2 (PO₂)
2. pH levels (Bohr Effect)
3. Temperature
4. CO2 levels
5. 2,3-BPG
118
How does PO₂ affect binding?
- High PO₂ (lungs): increased binding
- Low PO₂ (tissues): increased release
119
How does pH affect binding?
Lower pH (more acidic) causes hemoglobin to release oxygen more easily
120
How does temperature affect binding?
Higher temperature reduces affinity, promoting oxygen release
121
What's the purpose of varying affinity?
To efficiently bind O2 in lungs and release it in tissues that need it
122
What are the main factors affecting hemoglobin's O2 affinity?
1. PO₂ (oxygen partial pressure) 2. pH (Bohr Effect) 3. Temperature 4. BPG 5. CO₂ levels 6. Type of hemoglobin
123
What is the Bohr Effect?
Lower pH (more acidic) causes easier O2 release
124
How does temperature affect binding?
Higher temperature = easier O2 release
Lower temperature = tighter O2 binding
125
What does BPG do?
More BPG = easier O2 release
## Footnote
Increases during: Exercise, High altitude
126
How does fetal hemoglobin differ?
Higher O2 affinity than adult hemoglobin to extract O2 from mother's blood
127
What is PO₂?
Partial pressure of oxygen, measuring oxygen concentration in air/blood (in mmHg)
128
How does PO₂ affect hemoglobin binding?
- High PO₂: increased O2 binding
Low PO₂: increased O2 release
129
What is saturated hemoglobin?
- Fully loaded with O2
~95-100% saturation
Occurs at PO₂ ~100 mmHg
130
What is partially saturated hemoglobin?
- Carrying some but not maximum O2
~75% saturation
Occurs at PO₂ ~40 mmHg
131
What happens in active muscles?
- PO₂ drops to ~20 mmHg
Hemoglobin saturation 35-40%
Releases 60-65% of O2
132
How does pH affect hemoglobin's O2 affinity?
Lower pH (more acidic) = decreased affinity, easier O2 release. Higher pH (less acidic) = increased affinity, tighter O2 binding.
133
What happens during exercise?
- Muscles produce CO2
## Footnote
pH decreases, Curve shifts right, More O2 released to tissues.
134
What is the Bohr Effect?
Changes in pH/CO2 affect hemoglobin's O2 affinity, allowing adjusted O2 delivery based on tissue needs.
135
How does temperature affect O2 binding?
- Higher temperature = decreased affinity, easier O2 release
Lower temperature = increased affinity, tighter O2 binding
136
What happens in warm, active tissues?
- Temperature increases
Curve shifts right
More O2 released
Matches higher O2 needs
137
What happens in cooler tissues?
- Temperature decreases
Curve shifts left
O2 stays bound longer
Matches lower O2 needs
138
Why is this temperature effect important?
Helps match O2 delivery to tissue needs based on activity level
139
How does this work with exercise?
Active muscles:
Generate heat
Temperature rises
Get more O2 released
Meets increased demand
140
What is BPG?
2,3-bisphosphoglycerate, a molecule in red blood cells that decreases Hb's O2 affinity
141
How is BPG produced?
Byproduct of glucose breakdown during ATP production (glycolysis)
142
What does BPG do?
- Binds to hemoglobin
Decreases O2 affinity
Helps unload O2 from Hb
143
What affects BPG levels?
- Hormones (thyroxine, epinephrine)
Altitude
Energy production rate
144
Why is BPG important?
Helps ensure O2 delivery to tissues by making Hb release O2 more easily
145
How do hormones affect BPG?
Can increase BPG levels, leading to increased O2 release
146
What's special about fetal hemoglobin (HbF)?
Binds O2 more strongly than adult Hb.
## Footnote
Has less BPG; Curve shifts left compared to adult Hb.
147
Why does fetal Hb bind O2 more strongly?
Has less BPG, leading to higher O2 affinity.
148
What's the advantage of this system?
Allows fetus to effectively extract O2 from maternal blood even in low O2 conditions.
149
Key difference between fetal and adult Hb?
Fetal Hb has higher O2 affinity due to lower BPG levels.
150
What are the 3 forms of CO₂ transport?
1. Dissolved in plasma (7%)
2. Carbamino compounds (23%)
3. Bicarbonate ions (70%)
151
What are carbamino compounds?
- CO₂ bound to hemoglobin
## Footnote
Forms carbaminohemoglobin (Hb-CO₂). Binds to amino groups, not iron.
152
How does bicarbonate transport work?
1. CO₂ + H₂O → H₂CO₃ (carbonic acid)
2. H₂CO₃ → H⁺ + HCO₃⁻
3. HCO₃⁻ moves to plasma
4. Cl⁻ moves into RBCs (chloride shift)
153
What is the Haldane Effect?
Deoxygenated Hb:
- Binds more CO₂
- Binds more H⁺
Oxygenated Hb:
- Releases CO₂
- Releases H⁺
154
Which is the main transport method?
Bicarbonate ions (70%)
155
What controls respiratory muscle contraction?
Nerve impulses from respiratory center in brainstem
156
What are the two main parts of the respiratory center?
1. Medullary respiratory center (DRG and VRG)
2. Pontine respiratory group (PRG)
157
Where is the medullary respiratory center located?
In the medulla oblongata
158
Where is the pontine respiratory group located?
In the pons
159
What is the main function of the respiratory center?
Controls automatic breathing by managing muscle contractions and relaxations
160
How does the system work?
- Brain sends signals → muscles contract
Signals stop → muscles relax
Process is automatic
161
What changes during breathing?
Size of thorax (chest) changes as breathing muscles contract or relax
162
What are the main functions of DRG and VRG?
DRG: Controls quiet breathing
VRG: Controls forceful breathing
Pre-Bötzinger complex: Sets breathing rhythm
163
How does quiet breathing work (DRG)?
1. 2-second nerve impulses
2. Activates diaphragm and external intercostals
3. Muscles contract = inhalation
4. Signals stop = passive exhalation
164
What happens in forceful breathing (VRG)?
Activates accessory muscles
## Footnote
Forceful inhalation: uses sternocleidomastoid, scalenes
Forceful exhalation: uses internal intercostals, abdominals
165
What's the pre-Bötzinger complex?
Located in VRG
Acts as breathing pacemaker
Controls timing of breathing cycle
166
What triggers VRG activation?
Need for more oxygen (e.g., during exercise)
167
What's the breathing cycle timing?
Inhalation: 2 seconds (active)
Exhalation: 3 seconds (passive in quiet breathing)
168
What is cortical control of breathing?
Allows conscious control of breathing (e.g., holding breath)
169
What limits voluntary breath-holding?
- CO2 buildup
## Footnote
Increased H+ (acidity) Automatic breathing resumes when levels too high
170
What are chemoreceptors?
Sensors that monitor:
- O2 levels
- CO2 levels
- H+ levels
171
What are the two types of chemoreceptors?
1. Central: near medulla (detect CSF CO2/H+)
2. Peripheral: in aortic/carotid bodies (detect blood O2/CO2/H+)
172
How are peripheral chemoreceptors connected?
- Aortic bodies: vagus nerve (X)
- Carotid bodies: glossopharyngeal nerve (IX)
173
Why is this control system important?
- Allows voluntary breathing control
## Footnote
Prevents injury from breath-holding Maintains safe blood gas levels
174
What are central chemoreceptors?
- Located near medulla oblongata
## Footnote
Monitor CO2 and H+ in cerebrospinal fluid
Main CO2 detectors
175
What are peripheral chemoreceptors?
- Located in aortic and carotid bodies
## Footnote
Monitor blood levels of:
O2
CO2
H+
176
How do central chemoreceptors work?
- Detect increased CO2 → increased acid
## Footnote
Signal brain to increase breathing
Primary CO2 monitoring system
177
How do peripheral chemoreceptors work?
Monitor blood chemistry and signal when:
## Footnote
O2 too low
CO2 too high
Blood too acidic
178
What's the difference between central and peripheral chemoreceptors?
Central: Monitor brain fluid (CSF)
Peripheral: Monitor blood
179
Why have both systems?
Provides comprehensive monitoring of:
## Footnote
Brain conditions (central)
Body conditions (peripheral)
180
What is hypercapnia?
High blood CO2 levels causing:
- Increased blood acidity
- Stimulation of central chemoreceptors
- Increased breathing rate
181
How does body respond to hypercapnia?
Negative feedback:
- DRG increases activity
- Causes hyperventilation
- Removes excess CO2
182
What happens in severe hypercapnia?
Positive feedback cycle:
- Depresses breathing centers
- Reduces breathing
- CO2 increases further
183
What is hypocapnia?
- Low blood CO2 levels
- DRG slows breathing
- Waits for CO2 to build up
184
Which is more important for breathing control?
Rising CO2 levels stimulate DRG more strongly than falling O2 levels
185
Why is this important to know?
- Explains dangers of hyperventilation
- Shows why CO2 balance is crucial
- Helps understand breathing regulation
186
What is the stimulus that disrupts respiratory homeostasis?
High PCO₂ (increased CO₂) and/or low PO₂ (decreased O₂) in blood, leading to decreased pH (more acidic blood)
187
What are the controlled conditions in respiratory homeostasis?
Blood levels of:
- PCO₂ (carbon dioxide)
- pH (acidity)
- PO₂ (oxygen)
188
What do central chemoreceptors detect and where are they located?
Located: in medulla
Detect: CO₂ and H⁺ (acidity) in cerebrospinal fluid
189
What do peripheral chemoreceptors detect and where are they located?
Located: in aortic and carotid bodies
Detect: CO₂, pH, and O₂ levels in blood
190
What is the control center for respiration?
Dorsal Respiratory Group (DRG) in medulla oblongata
191
What are the effectors in respiratory control?
Respiratory muscles:
- Diaphragm
- External intercostal muscles
Action: Contract more forcefully and frequently (hyperventilation)
192
What is the response to high CO₂ levels?
- Increased breathing rate and depth
Decreases PCO₂
Increases pH (less acidic)
Increases PO₂
193
How is homeostasis restored?
- Hyperventilation removes excess CO₂
Blood chemistry returns to normal
Chemoreceptors stop signaling
Breathing returns to normal rate
194
What type of feedback system controls respiration?
Negative feedback system
195
What is the complete pathway of respiratory control?
Stimulus → Controlled Condition → Receptors → Control Center (DRG) → Effectors → Response → Return to Homeostasis
196
What is hypoxia?
Oxygen deficiency at tissue level due to low arterial blood PO2
197
What is hypoxic hypoxia?
- Caused by low oxygen in air (high altitude)
## Footnote
Like 'thin air' at high elevations. Reduced oxygen pressure for blood uptake.
198
What is anemic hypoxia?
- Too little functioning hemoglobin
## Footnote
Can't carry enough oxygen. Caused by: Anemia, Carbon monoxide poisoning, Blood loss.
199
What is ischemic hypoxia?
- Reduced blood flow to tissues
## Footnote
Like a traffic jam blocking oxygen delivery. Caused by: Heart attack, Blood clots, Poor circulation, Shock.
200
What is histotoxic hypoxia?
- Cells can't use available oxygen
## Footnote
Caused by toxic agents in tissue cells. Examples: Cyanide poisoning, Alcohol poisoning, Drug overdoses.
201
How does breathing change at the start of exercise?
Changes immediately, before blood chemistry changes (O2, CO2, pH)
202
What are proprioceptors and what do they do?
- Motion sensors in muscles and joints
## Footnote
Monitor body movement, signal DRG to increase breathing rate/depth, activate before chemical changes occur.
203
How does the motor cortex help with exercise breathing?
Sends two simultaneous signals:
## Footnote
To muscles for movement, to breathing center to prepare for exercise.
204
What are baroreceptors?
- Stretch sensors in lungs
## Footnote
Monitor lung inflation, act as safety system, prevent over-inflation.
205
How do baroreceptors work?
1. Detect lung over-inflation 2. Send signals to DRG 3. DRG is inhibited 4. Breathing muscles relax 5. Exhalation occurs
206
What's the relationship between these systems?
- Proprioceptors: Early warning system
Motor signals: Preparation system
Baroreceptors: Protection system
## Footnote
All work together for efficient, safe breathing during exercise.
207
What two factors influence respiratory and cardiovascular adjustments during exercise?
1. Intensity (how hard)
2. Duration (how long)
208
What is pulmonary perfusion and how does it change during exercise?
- Definition: Blood flow to lungs
Changes: Increases with cardiac output
Purpose: Matches increased blood flow to body
209
How does O2 diffusing capacity change during exercise?
- Can increase up to 3× during maximal exercise
More capillaries open
Creates larger surface area for O2 transfer
210
What are the immediate responses to exercise?
Neural responses:
- Exercise anticipation
- Muscle/joint sensor activation
- Brain movement signals
- Quick breathing increase
211
What are the gradual changes during exercise?
Blood Chemistry changes:
- O2 levels slightly decrease
- CO2 levels increase
- Body temperature rises
Breathing changes:
- Moderate exercise: deeper breaths
- Intense exercise: faster and deeper breaths
212
How does recovery work?
Quick changes:
- Rapid drop in breathing rate
Gradual changes:
- Blood chemistry normalizes
- Temperature decreases
- Breathing returns to rest rate
