Pulmonary Circulation and Vasoconstriction

University:
The University Of Western Ontario
Course:
ANAT 2200B | Systemic Anatomy of the Human Body
Academic year:

2022
Views:

322

Pages:

5
Author:

Kyuwon J.

Hypoxic pulmonary vasoconstriction ● Trigger ○ Low alveolar PO2 ○ Hypoxia in an alveolus ● Response ○ Pulmonary arterioles ⇒ constriction into the region ● High-yield contrast ○ Systemic circulation ■ Hypoxia ⇒ vasodilation ● Allows for delivering more blood ○ Pulmonary circulation ■ Hypoxia ⇒ vasoconstriction ● Redirect blood When HPV is critical ● Global hypoxia ○ Not just one patch ■ High altitude ■ Severe COPD ● Widespread of hypoventilation ● Result ○ Widespread vasoconstriction ⇒ increase in pulmonary vascular resistance ⇒ pulmonary hypertension ○ Chronic ⇒ RV strain ■ Core pulmonale concept Oxygen assist ● Giving oxygen increases in alveolar PO2 ventilated unit ⇒ reduction of unnecessary HPV ⇒ improvement in overall gas exchange efficiency ● When V/Q mismatch, works best ● Does not work well with the true shunt ○ V=0 Quick pattern recognition list ● PE ○ High V/Q ■ Dead space ○ Dyspnea ○ Tachycardia ● Pneumonia ○ Low V/Q ■ Shunt-like ○ Bronchial breath sounds ○ Dullness ● Atelectasis ○ Very low V/Q ○ Shunt possibility ○ Decrease in breath sounds ○ Volume loss signs ● Asthma ○ Uneven ventilation ○ V/A mismatch wheeze Memorization!! ● Apex = High V/Q ● Base = Low V/Q ● HPV ○ Lower alveolar O2 ⇒ pulmonary vasoconstriction ● Oxygen assist with V/Q mismatch ○ Greater than true shunt Consolidation ● Alveoli is filled with other material ○ Pus/exudate ■ Pneumonia ○ Fluid ■ Pulmonary edema ○ Blood ■ Alveolar hemorrhage ○ Cells ■ Inflammatory ■ Malignant processes Pulmonary circulation ● Gas exchange group ● RV ⇒ pulmonary trunk ⇒ Right and left pulmonary arteries ⇒ lobar or segmental arteries ⇒ capillaries ⇒ pulmonary veins ⇒ LA ● Used for gas exchange only ○ Not used for nutrition ○ Nutrition transport is done by bronchial arteries Pulmonary trunk and pulmonary arteries ● Pulmonary trunk ○ Exits to the right ventricle ○ Division to right and left pulmonary arteries ■ Around T4/5 region ● Right pulmonary artery ○ Longer path to right lung ■ Towards right hilum ● Left pulmonary artery ○ Shorter ○ Passes to left hilum ● Hilum relation ○ RALS ○ Right PA = Anterior of bronchus ○ Left PA = Superior of bronchus Pulmonary veins ● 2 pulmonary veins per lungs(usually) ○ Superior ○ Inferior ● Transports oxygenated blood to left atrium ● In anterior-inferior of the hilum ○ Significant for CT orientation Bronchial vs pulmonary vessels ● Pulmonary arteries ○ Low pressure ○ Following bronchi ○ Delivery of blood ■ For gas exchange ● Bronchial arteries ○ Systemic pressure ■ From thoracic aorta region ○ Supply bronchial walls ○ Supply connective tissue ○ Bronchial venous drainage ■ Goes to azygos system ■ Partially mixed with pulmonary venous return Pulmonary embolism ● PE = clot lodging in pulmonary aterial tree ● DVT travels to lungs ● Main pulmonary arteries ○ Large PE ● Lobar or segmental arteries ○ Common ● Subsegmental ○ Small, sometimes could be incidental