Respiratory Physiology Intro Flashcards
What are the four purposes of pulmonary system?
supply O2/remove CO2
maintain acid/base
phonation
pulmonary defence
Partial pressure of gases at 1 atmosphere
O2: 160 mmHg
N2: 600 mmHg
CO2: 0.3 mmHg
H2O: 3 mmHg
What does anaerobic metabolism yield?
2 ATP, pyruvate, and lactic acid
Where does anaerobic metabolism occur?
glycolysis occurs in the cytoplasm
Where does aerobic metabolism occur?
The mitochondria
What does aerobic metabolism yield?
38 ATP, CO2, water, heat
What innervates the cricothyroid muscle?
SEM (SLN external motor)
What innervates the majority of the larynx motor?
RLN
What innervates the sensory (VC and above)
SLN (internal)
What innervates the sensory (VC and below)
RLN
Abduction of vocal cords
Posterior CricoArytenoid (please come apart)
Adduction of vocal cords
Lateral CricoArytenoid (let’s close airway)
Relaxation vocal cords
ThyroaRytenoid (they relax)
Tension of vocal cords
CricoThyroid (cords tense)
What is the degree of angle for right bronchus?
25
What is the degree of angle for the left bronchus?
45
What % of TLC is the right lung?
55% and it is 3 lobes
What % of TLC is the left lung?
45% and it is 2 lobes
How many generations do the lungs have?
20-25 generations (bifurcations) with 10 bronchopulmonary segments
What is the conducting zone?
Generation 0 - 16
Trachea –> Bronchi –> Bronchioles –> Terminal Bronchiol
NO GAS EXCHANGE
Goblet cells here
What is the respiratory/transitional zones?
Respiratory bronchioles –> Ducts –> Sacs
Phrenic nerve innervation
C3, C4, C5 nerve roots bilaterally
Muscles for inspiration
Diaphragm, external IC (forced)
Muscles for expiration
passive
forced: internal IC, abdominal muscles
What are the three types of pneumocytes?
Type I: structural
Type II: surfactant producing
Type III: Macrophages (alveolar) monocyte that moved into tissue conducting airways
How many alveoli do humans have? What is their surface area?
300 million; 60 - 80 m^2
What is the distance from the front incisors to the carina?
26 cm (13 from teeth to larynx; 13 from larynx to carina)
What are the type of cells in the conducting zone?
Pseudostratified ciliated epithelium –> ciliated columnar epithelium –> cuboidal epithelium
*mucus-secreting goblet cells are also present
What is the blood supply in the conducting zone?
thyroid, bronchial, internal thoracic arteries (systemic circulation)
What is the size of the terminal bronchioles? What do they lack?
1 mm
Lack cartilaginous plates
What makes up anatomic dead space?
The conducting zone!!
How do you measure anatomic dead space?
150 mL
1/3 the Vt
1 mL/lb or 2 mL/lb (IBW)
What are the cells of the respiratory zone?
cuboidal –> squamous
What is the blood supply to the respiratory zone?
Pulmonary.. duh
What is the size of the respiratory bronchioles?
0.5 mm; flow moves by diffusion at this point
Name the accessory muscles for inspiration
sternocleidomastoid & scalene
Name the accessory muscles for expiration
rectus, internal/external obliques, transverse abdominus
Transpulmonary pressure
the difference between the intrapleural and intra alveolar pressures; it determines the size of the lungs. a higher transpulmonary pressure corresponds to a large lung
What are the components of WOB?
Elastive
Resistive
Discuss the medulla’s control over breathing
DRG: pacemaker for breathing; stimulates inspiration
VRG: stimulates inspiration/expiration (forced)
Discuss the pon’s control over breathing
Modifies the medulla output.
- Pneumotaxic: decreases Vt for fine control (located high in the pons)
- Apneustic: increases Vt for long, deep breathing (located lower in the pons)
* output limited by baroreflex, pneumotaxic*
How do central chemoreceptors work?
respond to H+ ions
How do peripheral chemoreceptors work?
respond to CO2, pH, and hypoxemia
What carries the aortic arch and lung stretch signals?
Vagus (X) carries it to the DRG
What carries the carotid body signals?
Glossopharyngeal (IX) carries it to the DRG
Parasympathetic control over the airway
From vagus (X) Causes: mucous secretion, increased vascular permeability, vasodilation, bronchospasm, bronchoconstriction (greatest in upper airway)
Sympathetic control over the airway
intrinsically, small effect –> inhibit mediator release from mast cells, increase mucociliary clearance
What is the Vt of a patient?
usually 6-8 ml/kg IBW