Direct determination of luminal diameter changes in intrapulmonary airways

Respiration; International Review of Thoracic Diseases
G N MelvilleJ Minnis


A method is described for the direct measurement of changes in luminal diameter at all levels of the airway. Using this method it was found that (i) abrupt bronchiolar collapse occurred in the preterminal and terminal bronchioles once the luminal diameter was reduced to a critical level: (ii) decreased temperatures resulted in airway narrowing which was reversed by increasing the temperature to above 25 degrees C; as a rule, airway narrowing followed a cranial to caudal direction, and higher concentration of a drug being required to close the peripheral airways; (iii) bronchodilators except Carbuterol had no effect on resting bronchial tone or on acetylcholine-induced constriction in the absence of alpha-adrenoceptor blockade; (iv) at 35 degrees C rhythmic waves (frequency 6--20/min) were observed; these waves travelled from the periphery in a cranial direction.

Related Concepts

Nerve Impulses
Adrenergic beta-Agonists
Lobar Bronchus Structure
Muscle Tonus
Smooth Muscle
Rats, Laboratory

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Synthetic Genetic Array Analysis

Synthetic genetic arrays allow the systematic examination of genetic interactions. Here is the latest research focusing on synthetic genetic arrays and their analyses.

Neural Activity: Imaging

Imaging of neural activity in vivo has developed rapidly recently with the advancement of fluorescence microscopy, including new applications using miniaturized microscopes (miniscopes). This feed follows the progress in this growing field.

Computational Methods for Protein Structures

Computational methods employing machine learning algorithms are powerful tools that can be used to predict the effect of mutations on protein structure. This is important in neurodegenerative disorders, where some mutations can cause the formation of toxic protein aggregations. This feed follows the latests insights into the relationships between mutation and protein structure leading to better understanding of disease.

Congenital Hyperinsulinism

Congenital hyperinsulinism is caused by genetic mutations resulting in excess insulin secretion from beta cells of the pancreas. Here is the latest research.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Epigenetic Memory

Epigenetic memory refers to the heritable genetic changes that are not explained by the DNA sequence. Find the latest research on epigenetic memory here.

Cell Atlas of the Human Eye

Constructing a cell atlas of the human eye will require transcriptomic and histologic analysis over the lifespan. This understanding will aid in the study of development and disease. Find the latest research pertaining to the Cell Atlas of the Human Eye here.

Femoral Neoplasms

Femoral Neoplasms are bone tumors that arise in the femur. Discover the latest research on femoral neoplasms here.