Summary Topic 2 Gas Exchange

Gas exchange surfaces

Epithelium Eithelial cells/tissuel
P
layer/lining
↳ alveoli
airways
+




S.I units Squamous -
flat cells - reduces
diffusion distance


Columnar -
>
airways

Simple
layered
=

Single epithelial tise

stratified ered epithelial tissue


Psuedostratified columnar -



appears
to be multiple layers but is




single
The
airways are
psuedostratified columnar epithelial cell which
are ciliated


Top membrane of epithelial cells is the apical membrane
Lower membrane is the basal membrane connected to the basement
membrane




Cilia -
hairlike structures on cells within
airways

Cells which ciliated
waft away from
-

are mucus

the to be
lungs coughed or swallowed




Mucus -produced and secreted
by goblet cells found in the airways


-


traps dust, debris and pathogens to protect longs
-
Mucus is H2O and Mucins (glycoproteins) gel
-
like substance



Villi hair like
projections formed by cells
folding the
lining of the
-


on

small intestine

-

Microvilli , found the cells
on he
in villi
byhe phospholipid membrane

folding