Bronchial + Pulmonary Circulation
Pulmonary Veins
O2 blood from lungs to LA -2 per side -run independent of PA/bronchi -receive deO2 blood from bronchial veins + visceral pleura via shunts *do NOT collapse: tethered by septa
Hemoptysis
--> bleeding from bronchial arteries 90% of time -high pressure so significant bleeding -embolotherapy for persistent bleeding
Bronchopulmonary Lymph Nodes
--> drain to sup. + inf. tracheobronchial lymph nodes sup. + inf. to bifurcation
Treating Cystic Fibrosis with Gene Therapy
--> inject gene delivery vectors into bronchial arteries --> reaches mucous secreting cells + submucosal glands
Unilateral Lung Disease
--> position with good lung down so more blood for gas exchange via gravity
Exercise
--> recruitment + distention of capillaries increases blood flow 4-7X
Pulmonary Lymph Nodes
-along lobar bronchi --> follow bronchi to hilum --> drain to bronchopulmonary lymph nodes
Superficial (Subpleural) Lymphatic Plexus
-deep to visceral pleura -lymph from visceral pleura + lungs --> drain to bronchopulmonary (hilar) lymph nodes
Bronchial Veins - Deep System
-drains lung parenchyma deep to segmental divisions -drains into pulmonary veins between segmental septae (bronchopulmonary anastamosis)
Bronchial Veins - Superficial System
-drains visceral pleura + hilum -R: converge to azygous -L: converge to hemiazygous or L. sup. IC vein -may receive tracheal/mediastinal veins
R. PA
-longer than L. -runs horizontally across mediastinum -ant. to trachea/bronchi -post. to aorta, SCV, pulmonary veins
Importance of Bronchial Circulation
-modulates mucociliary transport: nutrient flow -maintain airway wall temp. + humidity + release of mediators + sequelae associated with tissue ischemia
L. Tracheobronchial Lymph Nodes
-receives from L. sup. lobe --> L bronchomediastinal lymph trunk--> thoracic duct
R. Tracheobronchial Lymph Nodes
-receives from R. lung + L. LOWER LOBE --> R. bronchomediastinal lymph trunk --> R. lymphatic trunk
L. PA
-shorter than R. -ant. to descending aorta + bronchus -post. to pulmonary veins
Deep Bronchopulmonary Lymphatic Plexus
-submucosal of bronchi + peribronchial C.T. -drain root of lung --> pulmonary lymph nodes along lobar bronchi --> bronchopulmonary lymph nodes
Pulmonary Embolism
b/c DVT (deep vein thrombosis) in lower extremities --> small segmental vessels --> sudden death -commonly affects lower lobes -infarction in few because of dual circulation
Pulmonary Arteries
deoxygenated blood to lungs from pulmonary trunk/RV -compliant --> susceptible to deformation -gives off sup. lobar branch BEFORE entering hilum -paired with bronchi ant., simultaneous branching, parallel courses
Bronchial - Pulmonary Circulation Connections
1. arterial anastamosis along bronchioles -arterio-venous shunt 2. precapillary arterioles in plura + bronchial walls + pulmonary veins 3. bronchial to pulmonary flow: bronchial vein drains to pulmonary veins
L. Bronchial Arteries
2: sup. + inf. -straight from aorta lateral to carina, post. to L. main bronchus
Zone I
= alveolar dead space -towards apices -present in abnormal conditions mostly (hypovolemia) -P alveolar > P arterial
Zone III
= continuous blood flow -lower regions -P alveolar is much less than P arterial -P arterial high during systole and diastole
Perfusion Zones
= functional zones of lungs: vascular vs. alveolar pressure -3 zones according to gravity
Zone II
= intermittent blood flow -10 cm above heart level to top of lungs -Pulmonary artery pressure > P alveolar in systole
Extra-alveolar Vessels
= pulmonary arteries + arterioles -sensitive to intrapleural pressure --> increase lung volume decreases resistance of vessels
Infra-Alveolar Vessels
= pulmonary capillaries next to alveoli -increased lung volume increases resistance b/c vessels are stretched and lumen is crushed
R. Bronchial Artery
ICBT -may give off spinal arteries -comes off trunk with R. 3rd post. IC artery, passes BEHIND trachea
Dual Circulation in Lungs
Pulmonary + Bronchial circulation
Pulmonary Circulation
for gas exchange with alveoli, 95% cardiac output -low pressure/resistance --> increase blood flow will not increase pressure b/c increased density of capilaries open --> hypoxia causes increased pulmonary vascular resistance VASOCONSTRICTION (diverts blood to functioning areas instead) --> could lead to Pulm. HTN when prolonged (COR PULMONALE = R. side lung failure)--> corckscrew appearance of lungs
Lymphatic Drainage
pulmonary lymph plexuses that communicate freely --> spread bronchogenic carcinoma
Bronchial Circulation
systemic flow from aorta T5/6 to supply lung tissues, 1% CO -high pressure -runs along airway -anastamoses with pulm. circulation -2 L, 1 R. (ICBT = intercostobrachial trunk) -supplies: 1. extra + intrapulmonary airways 2. bronchovascular bundles + nerves 3. lymph nodes + visceral pleura 4. vasa vasorum+ pulmonary vessels -drains to azygous, hemiazygous, + O2 pulmonary veins
