All articles starting with P

Pulmonary alveolar type 1 cell

Pulmonary alveolar type 1 cell (AT1, type I pneumocyte): flattened squamous epithelial cell covering over 95% of the alveolar surface, forming the thin air-blood barrier for gas exchange, marked by AQP5, PDPN, AGER, HOPX, and largely renewed from AT2 cells after injury.

Pulmonary alveolar type 2 cell

Pulmonary alveolar type 2 cell (AT2, type II pneumocyte): cuboidal surfactant-secreting alveolar epithelial cell with lamellar bodies, covering about 5% of alveolar surface, acting as the adult distal lung stem cell that renews AT1 cells.

Pulmonary angiography

Pulmonary angiography is an invasive imaging procedure that injects contrast into the pulmonary arteries to diagnose embolism; once the gold standard, it has largely been replaced by CT angiography.

Pulmonary arterial hypertension

Pulmonary arterial hypertension is a rare, Group 1 form of pulmonary hypertension in which small lung arteries remodel and narrow, raising resistance and eventually causing right heart failure.

Pulmonary arteriovenous malformation

Pulmonary arteriovenous malformation (PAVM), also called pulmonary arteriovenous fistula: an abnormal artery-vein connection in the lung causing right-to-left shunt, stroke, and brain abscess risk; mostly linked to HHT, screened by contrast echocardiography, treated by embolization.

Pulmonary artery

Pulmonary artery (pulmonary trunk): the vessel carrying deoxygenated blood from the right ventricle to the lungs; about 5 cm long, 2-3 cm wide, bifurcates at T4; low-pressure, high-capacitance system with resistance about one-tenth systemic.

Pulmonary artery banding

Pulmonary artery banding (PAB) is a palliative heart operation, introduced by Muller and Dammann in 1951-1952, that constricts the pulmonary artery to cut excessive lung blood flow in congenital defects, single-ventricle palliation, and infant heart failure.

Pulmonary artery catheter

Pulmonary artery catheter, also called Swan-Ganz catheter or right heart catheter: balloon-tipped flow-directed device introduced by Swan and Ganz in 1970 to measure heart and lung pressures, cardiac output, and mixed venous oxygen saturation in critically ill patients; large trials showed no routine outcome benefit.

Pulmonary artery catheterization

Pulmonary artery catheterization, also called right heart catheterization, threads a balloon-tipped Swan-Ganz catheter through the right heart to measure pressures and cardiac output at the bedside.

Oct 20, 2026

Pulmonary artery endothelial cell

Pulmonary artery endothelial cells (PAECs) line the pulmonary arteries; markers include CD31, vWF, VE-cadherin. Distinct from microvascular ECs; central to PAH endothelial dysfunction, low NO, glycolytic shift, and anoikis resistance research.

Pulmonary artery hypoplasia

Pulmonary artery hypoplasia is a rare congenital anomaly in which a branch pulmonary artery is underdeveloped, causing shortness of breath, recurrent lung infections, and pulmonary hypertension.

Pulmonary artery pressure monitoring

Pulmonary artery pressure monitoring is hemodynamic monitoring in which a small implantable sensor in a pulmonary artery measures blood pressure remotely, allowing heart failure treatment to be adjusted before congestion worsens.

Pulmonary aspiration

Pulmonary aspiration: entry of oropharyngeal or gastric material into the lower airway. Causes chemical pneumonitis (Mendelson's syndrome) or aspiration pneumonia; key risks are dysphagia, stroke, anesthesia, and reduced consciousness.

Oct 20, 2026

Pulmonary atresia

Congenital pulmonary atresia: a critical congenital heart defect in which the pulmonary valve does not form, blocking right ventricular blood flow to the lungs; two types (with intact ventricular septum or with VSD), about 1 in 8,333 US births, treated with prostaglandin, shunts, and staged surgery.

Pulmonary atresia with intact ventricular septum

Pulmonary atresia with intact ventricular septum (PA-IVS) is a rare congenital heart defect in which the pulmonary valve fails to develop, causing cyanosis in newborns.

Pulmonary atresia with ventricular septal defect

Pulmonary atresia with ventricular septal defect (PA/VSD), also called PA-VSD, is a critical congenital heart defect with an absent pulmonary valve and a VSD, often supplied by MAPCAs, repaired by unifocalization.

Pulmonary auscultation

Pulmonary auscultation is a physical examination method in which a stethoscope placed on the chest wall detects abnormal breath sounds, supporting diagnosis of pneumonia, heart failure, and pneumothorax.

Pulmonary blastoma

Pulmonary blastoma (pneumoblastoma) is a rare adult biphasic sarcomatoid lung cancer mimicking fetal lung, under 0.25% of lung tumors, ~350 reported cases, treated by surgery, distinct from childhood pleuropulmonary blastoma.

Pulmonary capillaritis

Pulmonary capillaritis (alveolar capillaritis) is neutrophilic inflammation and necrosis of alveolar capillary walls causing diffuse alveolar hemorrhage, usually from ANCA-associated vasculitis or collagen vascular disease, rarely isolated.

Pulmonary capillary hemangiomatosis

Pulmonary capillary hemangiomatosis (PCH), grouped with PVOD as PVOD/PCH, is a rare pulmonary vascular disease of abnormal alveolar capillary proliferation causing pulmonary hypertension, linked to biallelic EIF2AK4 mutations, treated by lung transplantation.

Pulmonary circulation

Pulmonary circulation carries deoxygenated blood from the right ventricle through the pulmonary arteries to the lungs and returns oxygenated blood to the left atrium; a low-pressure, low-resistance circuit first described by Ibn Al-Nafis.

Pulmonary collapse

Pulmonary collapse, or atelectasis, is deflation of part or all of a lung to an airless state, usually after anesthesia; distinct from pneumothorax, ICD-11 CB40.2, treated by reexpansion.

Pulmonary contusion

Pulmonary contusion: trauma-induced lung hemorrhage and edema without laceration, usually from blunt chest trauma; diagnosed by CT, treated supportively with oxygen, analgesia, and lung-protective ventilation; complications include pneumonia and ARDS.

Pulmonary cryptococcosis

Pulmonary cryptococcosis, lung infection from inhaled Cryptococcus neoformans or gattii spores, causing nodules, cough, often asymptomatic; treated with fluconazole or amphotericin B plus flucytosine.

Pulmonary Diffusing Capacity

Pulmonary diffusing capacity (DLCO, TLCO) measures carbon monoxide transfer from alveoli to blood, reflecting membrane area, capillary blood volume, and hemoglobin; developed by Marie Krogh in 1915 and standardized by Ogilvie in 1957.

Pulmonary edema

Pulmonary edema, abnormal fluid accumulation in lung interstitium and alveoli, occurs as cardiogenic (hydrostatic, left heart failure) or noncardiogenic (permeability, ARDS) types, distinguished by edema fluid protein ratio, wedge pressure, BNP, and imaging, and treated with oxygen, diuretics, nitrates, and ventilation.