Lecture 4 - Physiologic Basics of The Lung Exam Flashcards
back of the nose and throat
- nasal cavity and the pharynx (nasopharynx)
cartilaginous structure containing vocal folds
larynx
midline, non-paired conducting air-way
trachea
branching airways containing variable amounts of cartilage
Bronchi
3 lobes?
right lung
2 lobes with cardiac notch?
Left lung
branching airway lacking cartilage surrounded by smooth muscle
Bronchioles
delicate, balloon like structures where gas exchange occurs
Alveoli
Ventilation:
- the conducting zone
- skeletal muscle changes V of thoracic cavity -> pressure change -> air moves
- conducting airways: nasopharynx -> terminal bronchiole
- air moves in due to pressure gradient
Diffusion:
- respiratory/exchange zone
- Driven by concentration gradient
- extreme SA vasculature over the alveoli
- respiratory bronchiole -> alveoli
What is the V after a quiet inspiration?
3L
What are the components of the Ventilatory apparatus?
- lungs
- chest wall
- muscles
What muscles are active during inspiration?
- external intercostals - move ribs up ad out
- diaphragm - contracts and decends
V of thoracic cavity increases -> decreasing intrathoracic pressure -> decreasing pressure in lungs -> movement of air into lungs
What muscles become active during forced inspiration?
scalenes and SCM
What muscles are involved in expiration?
diaphragm - relaxes and rises
external intercostals - relax, moving ribs down and in
V thoracic cavity decreases -> increasing intrathoracic pressure -> increasing airspace lung pressure -> movement of air out
What pleura lines the lungs?
visceral pleura
Which pleura lines the chest wall?
parietal pleura
The space between visceral and parietal pleura?
pleural cavity/intrapleural space
Features of the pleural cavity:
- contains small amount of water - ‘connects’ chest wall to alveoli
- movement of thoracic cage and diapgragm -> change in pleural cavity pressure (slightly more negative) -> change in alveolar pressure
- alevoli expand as lungs expand
- intrapleural pressure is always lower than alveoli
What is the role of the nasal cavity?
warming and moistening air
what is the role of the Larynx?
phonation (speaking) and protection of airways from fluid/food
Key aspects to Pleural Effusion (unilateral):
- fluid in pleural cavity causing too much pressure - difficult for airpaces to expand
- lungs are dull to percusion
- difficult to hear breathing
- causes: cancer, infection, trauma
Key aspects to Pleural Effusion (bilateral):
- fluid in pleural cavity causing too much pressure - difficult for airpaces to expand
- lungs are dull to percusion
- difficult to hear breathing
- causes: something systemic, congestion due to heart failure, bilateral infection, inflammation
What is Consolidation?
“gunk” in the airways and alveoli
coarse crackles -> fluid in larger airways
* both inspiration and expiration
fine crackels -> smaller airways
* both inspiration and expiration
Causes: infectious mostly
hear: coarse crackles, bronchophony, decreased breathe sounds, dull percussion
if it is higher up - as you ausciltate down find normal sounds
Wheeze:
small airway is narrowed/constricted
high-pitched musical sound
common in: asthma, COPD, inflammation of bronchioles, pulmonary edema
inspiration normal
experation - hear it
Stridor:
large airway narrowed/constricted
louder, harsher sound on inspiration (sometimes also expiration)
in upper airways (trachea and above)
causes: infection, trauma, aspiration
