Unit 3: Pulmonary Physiology Pt2 Flashcards
What are the 20 generations of branching of the airway in lung?
Trachea –> Bronchi (11) –> Bronchioles (5)–> Respiratory Bronchioles (4) –> Alveolar ducts –> alveolar sacs –> Alveoli
What part of the branching of the airway in the lungs lacks cartilage?
bronchioles and those that follow
What happens to surface area as we go down the branching in the lungs?
surface area increases
trachea has 2 cm^2 and 300 million alveoli have 50-100 M^2
What is the area where gas exchange cannot occur called?
Dead space (mainly the airways)
What are two subcategories of the Dead space of our pulmonary branches?
- Anatomical Dead Space (=150ml)–> airways
2. Physiological Dead Space = anatomical + non-fxnal alveoli
What is the dead space that equals the anatomical dead space plus the non functional alveoli called?
Physiological dead space
How is the dead space calculated?
using a pure O2 inspiration and measuring nitrogen in expired air
– % area x Ve
How do we calculate the Alveolar volume?
= FRC - dead space
= 2300ml - 150ml
= 2150ml
(FRC = functional residual capacity)
Where is most of the FRC (functional residual capacity) at, at the end of a normal expiration?
at the level of the alveoli
How long does it take to turnover the alveolar air?
about 6-7 breaths
What is the equation for the rate of alveolar ventilation?** What does it equal?
Va = RR (Vt - Vd)
Va = alveolar ventilation RR= respiratory rate
Va = ~ 4 L/min**
What are the three ways Efferent Neural control of the airways occurs?
- SNS
- PSNS
- NANC Nerve (non-adrenergic, non-cholinergic)**
What will the SNS efferent neural control have on the airways? What type of receptors?
beta receptors–> causing dilation
What is the direct and indirect way the SNS can effect the airways? Which is predominant?
direct = weak due to sparse innervation
indirect = predominant via catecholamines
What type of receptors does the PSNS use to control the airways? What effect does it have on them?
muscarinic receptors –> causing constriction
What effect do NANC nerves have when they are inhibitory to the airways?
release VIP and NO = bronchodilation
What effect do NANC nerves have when they are stimulatory on the airways?
bronchoconstriciton, mucous secretion, vascular hyperpermeability, cough, vasodilation
= “neurogenic inflammation”
What stimulates the “neurogenic inflammation” of the airways?
NANC nerves (non-adrenergic and non-cholinergic)
What type of afferent nerve receptors are associated with smooth muscle of proximal airways and stretch receptors, involved in reflex control of breathing and cough reflex?
Slow Adapting receptors
What type of afferent never receptors are sensitive to mechanical simulation, protons, low Cl- solutions, histamine, cigarette smoke, ozone, serotonin, PGF?
Rapidly adapting receptors
(some response may be secondary to mechanical distortion produced by bronchoconstriction
What autonomic control of the airways is selectively stimulated by capsaicin?**
C-fibers (high density)
also activated by bradykinin, protons, hyperosmole solutions, and cigarette smoke
What effect will these local factors have on the smooth muscle of the airway?
- Histamine binds to H1 receptors
- Histamine binds to H2 receptors
- constriction
- dilation
(“1 before 2, and C before D”)
What effect will these local factors have on the smooth muscle of the airway?
- Prostaglandins E series
- Prostaglandins F series
- dilation
- constriction
(“take it E-asy and Dilate”
What effect will a slow reactive substance of anaphylaxsis (SRS-A) have on the airway smooth muscle?
constriction–> allergic response to pollen