Unit 4 Flashcards
Respiratory tree
Larynx Trachea Primary bronchi 2ndary bronchi Tertiary bronchi Bronchioles Terminal bronchioles Respiratory bronchioles Alveolar ducts Alveolar sacs with alveoli
Trachea supplies:
Both lungs
Primary bronchi supplies:
Each lung
2ndary bronchi supplies
Each lobe
Tertiary bronchi supplies:
Each bronchopulmonary segment (lobule)
Areas of the resp tree that are capable of gas exchange
Respiratory bronchioles
Alveolar ducts
Alveolar sacs with alveoli
Active muscles of inspiration
Diaphragm External intercostals Sternopcleidomastoid Serratus anterior Scalenus muscles
Muscles of expiration (only needed for FORCEFUL expiration)
Rectus abdominus, obliques
Internal intercostals
What increases during inspiration
Vertical diameter
AP diameter
What contracts during inspiration?
External intercostals
Diaphragm
What happens to the rib cage during inspiration
It elevates (duh)
What happens with internal intercostals during inspiration
They relax
Inspiration is due to:
Muscle contraction which increases thoracic cage size
Compliant lungs inflate due to:
Negative pressure in the pleural cavity
Expiration is due to:
Decreasing thoracic cage size bc of the elasticity of the thoracic soft tissue and the lungs themselves
What happens to alveolar pressure during inspiration?
Expiration?
Decreases during insp
Increases during exp
What happens to pleural pressure during inspiration?
Expiration?
Insp- decreases
Exp- increases
Tissue gradience between alveolar and pleural pressures
Transpulmonary pressure
Lung volume during inspiration?
Expiration?
Insp- increases
Exp- decreases
Intrapulmonary (alveolar) pressure oscillates around:
What happens when negative?
0
Air enters lungs (air leaves when positive)
The lowest intrapulmonary pressure is reached:
After that:
Halfway into inspiration
After that air entering the lungs raises the pressure
The highest intrapulmonary pressure is reached at:
After that:
Halfway into expiration
After that, air leaving the lungs reduces the pressure
Intrapleural pressure is always:
This exerts:
Negative compared to the atm, oscillating around -4.
This exerts an expanding effect on the lungs due to lung compliance
The difference between the alveolar pressure and the pleural pressure
Transpulmonary pressure
Ptrans = Plv - Pip