Histology of respiratory system Flashcards
why is the histological organisation of the inter alveolar wall important
for gaseous exchange
bronchioles look like
less than 1mm or less, smooth muscle increases, Clara cells are present, no goblet cells, non ciliated cells, no submucosal glands, no cartilage
gaps between rings of cartilage in trachea are filled by
trachealis muscle and fibroelastic tissue
what do respiratory mucosa and submucosa do
adapted to warm and moisten the air and trap foreign particles in mucous
what is lamina propria
lies under epithelium and has loose connective tissue that contains elastin and blood vessels
what is in submucosal layer
serous glands (secrete watery substances) , goblet cells (secrete mucous), ciliated cells
what does adventitia layer do
connects and supports trachea to surrounding tissue eg thyroid and oesophagus. contains nerves, vessels and adipose tissue
what type of epithelium in trachea
ciliated pseudo stratified columnar epithelium with goblet cells
what bronchi closely resembles trachea
extra pulmonary bronchi
what makes intrapulmonary bronchi different to extraplumonary bronchi
less cartilage and it does not completely circle the lumen
what makes intrapulmonary bronchi different to extraplumonary bronchi
less cartilage and it does not completely circle the lumen. contains layers of smooth muscle between the mucosa and submucosa
respiratory bronchioles type of cells
ciliated cuboidal epithelium
alveolar ducts histology
surrounded by smooth muscle, elastin and collagen
alveolar sacs histology
surrounded by blood vessels and pulmonary capillaries
alveoli histology
surrounded by blood vessels and pulmonary capillaries with very thin blood- alveoli barrier. where gas exchange occurs
major characteristics of bronchioles
smooth muscle layer is thicker, no cartilage, no glands, fewer cilia
histology of type I pneumocytes
large flattened cells
function of type II pneumocystes
secrete surfactant which decreases alveolar surface tension and stops alveoli collapsing when we breath out. more circular
macrophages (dust cells) histology
clump that are found in the lumen of alveolus and are brownish
what lies between the wall of capillary endothelial cell and alveolar cell
thin basement membrane
what do club cells/ Clara cells do
protect airways, produce surfactant, regenerate bronchiolar epithelium
respiratory portion of respiratory system has what kind of epithelium
gradual transition from cuboidal to simple squamous
