Airway Anatomy
This cartilage is the highest in the trachea and sits just below the larynx.
What is the cricoid cartilage?
This nerve innervates the diaphragm
What is the phrenic nerve?
Airway resistance (generally) decreases down the branches of the lung due to this.
Branching effect. What is increased cross-sectional area?
Name three factors that cause a rightward shift of the curve.
What are increased CO₂, increased H⁺ (low pH), increased temperature, or increased 2,3-DPG?
Gravity causes this distribution of perfusion in a lung (when standing up).
What is more blood flow to the base and less to the apex?
This is the only lobe that can be auscultated anteriorly and laterally.
What is T4/T5 (sternal angle)What is the right middle lobe?
This nerve causes tongue depression during inspiration.
What is the hypoglossal nerve (CN XII)?
This mechanical force helps keep alveoli open.
What is radial traction?
This effect enhances O₂ offloading at tissues due to high CO₂ and H⁺.
What is the Bohr effect?
These two mechanisms allow the pulmonary circulation to accommodate increased blood flow without a large rise in pressure.
What are recruitment and distension?
The tongue shaped projection around the heart bulge on the left lung
What is the lingula?
Each bronchosegment are functionally independent as it has its independent inflow of these 2 things
What is air and blood inflow?
Note: Pulmonary veins don’t follow the bronchi — they run intersegmentally, draining between segments
This part of the airway has the highest resistance.
What are the medium-sized bronchi?
This molecule shifts the oxygen dissociation curve to the right during hypoxia.
What is 2,3-DPG (BPG)?
This West Zone occurs at the lung apex when alveolar pressure exceeds capillary pressure.
What is West Zone 1 (capillary collapse)?
This allows the trachea to constrict during coughing or swallowing
What is the trachealis muscle?
These are the accessory muscles of inspiration
What are the sternocleidomastoid and scalene muscles
Fibrosis causes this change in compliance (increase/decrease).
compliance.What is decreased compliance?
On the oxygen dissociation curve, hemoglobin is almost fully saturated at this partial pressure of oxygen.
What is 100 mmHg?
Lying flat affects West zone distribution in this way.
What is it reduces vertical pressure gradients, causing most of the lung to function as Zone 3?
The superior component in the right lung hilum
What is the bronchus to the superior lobe?
This happens during post-inspiration
All nerves relax to restore airway pressure and begin to expel air….
Except the pharyngeal branch of the vagus nerve which innervate the adductor muscles of the upper airways --> narrowing --> slows the passage of air --> more gas exchange
Emphysema affects alveoli in this way
What is destroys elastic tissue and causes air trapping? Reduces elastic recoil?
This is the Haldane effect
What is "deoxygenated hemoglobin (Hb without O₂) has a higher affinity for CO₂ and H⁺. In tissues (where O₂ is offloaded), Hb becomes more ready to bind CO₂ and H⁺."?
Pulmonary arteries differ from systemic arteries in these three structural ways.
What are thinner walls, less muscle, and more elasticity?