Minimal distensibility of pulmonary capillaries in avian lungs compared with mammalian lungs.
Respir Physiol Neurobiol
; 160(2): 208-14, 2008 Feb 01.
Article
em En
| MEDLINE
| ID: mdl-17981521
Previous physiological studies suggest that avian pulmonary capillaries behave like almost rigid tubes. We made morphometric measurements to determine the diameter of the capillaries in chicken lungs when the transmural pressure was altered over a wide range. The diameter of avian pulmonary capillaries increased by only 13% when the pressure inside them was raised from 0 to 25 cmH(2)O. In contrast, other studies have shown that the mean width of the pulmonary capillaries in dogs increased by about 125% and in cats by 128% for the same pressure change. Furthermore, raising the pressure 35 cmH(2)O outside the capillaries compared to the pressure inside the capillaries in chicken lungs caused little change in diameter whereas under the same conditions in mammal lungs the capillaries are completely collapsed. We conclude that the epithelial bridges between the blood capillaries in the bird lung provide strong support to the capillaries both in expansion and compression.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Capilares
/
Resistência Capilar
/
Galinhas
/
Pulmão
Limite:
Animals
Idioma:
En
Revista:
Respir Physiol Neurobiol
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Estados Unidos