respiratory system Flashcards
what is the primary muscle in resp sys
diaphragm
explain inspiration
diaphragm contracts increasing thoracic cavity volume, air goes in
explain expiration
diaphragm relaxes, lungs collapse + expels air
what are the two classifications of the resp sys
conducting and respiratory zones
what is involved in the conducting zone
gaseous transport, filters, humidifies and warms air.
composed of nasal cavity, nasopharynx, larynx, trachea, bronchi, bronchioles
what is involved in the respiratory zone
site of gaseous exchange. composed of bronchioles, alveolar ducts, alveolar sacs and alveoli.
define olfaction
refers to smell
describe the respiratory mucosa
pseudostratified ciliated columnar epithelium with goblet cells.
has lamina propria- loose collagenous layer underlying the resp epi.
mucosal layer is separated by presence of a submucosa
describe the nasal cavity structure
divided into two nasal cavities which is separated by a nasal septum (cartilage). these cavities and the paranasal sinuses are lined by resp mucosa
bones called turbinate bones project into the nasal cavities.
what does the lamina propria of nasal mucosa contain
serous and mucous glands
nasopharynx
space above soft palate at back of the nose. this connects the nose to the mouth. consists of pseudo. ciliated columnar epi. serous and mucous glands in lamina prop
General structure of trachea
flexible tube of fibroelastic cartilage. has a series of c shaped rings of hyaline cartilage that supports the tracheal mucosa, which prevents the trachea from collapsing during inspiration.
smooth muscle - trachealis muscle joins the free ends of the rings posteriorly. longitudinal muscle can be found behind the trachealis muscle.
describe the respiratory epithelium of the trachea
epithelium is similar to rest of the RS.
variety oc cells found include:
- pseudostratified columnar cells with cilia
- goblet cells and basal cells (upper trachea)
- serous cells and stem cells (lower trachea)
beneath the basement membrane: lamina propria and submucosa (mixed seromucinous glands).
describe the structure of primary bronchi
respiratory epi = shorter than trachea with fewer goblet cells
lamina propria= more dense with large quantity of elastin
LP separates from submucosa by smooth muscle, which has less seromucinous glands
has a cartilage framework which is arranged into flattened plates rather than rings.
describe the primary bronchi resp epithelium
pseudostratified, with some ciliated cells.
have goblet cells, and LP has elastin and mast cells.
describe tertiary bronchi
tall and columnar, goblet cells diminished in number.
LP is thin and encircled by smooth muscle which permits contraction of the bronchi.
submucosa has sparse seromucinous glands
cartilage framework reduced to a few irregular plates.
small aggregations of lymphoid tissue
describe structure of bronchioles
no cartilage support, no submucosal glands. ciliated columnar cells, few goblet cells, clara cells.
smooth muscle layer found in bundles in various orientations
describe terminal and respiratory bronchioles
terminal: smallest passages of CZ. each branches into respiratory branches (bronchioles)
respiratory bronchioles
- ciliated cuboidal cells
- no goblet cells
- clara cells: produce surfactant, act as reserve cells (stem cells) and contain enzymes for detoxification
- each gives rise to alveolar duct + sac
describe alveolar wall
epithelium
type 1 pneumocytes: large squamous cells, alveolar lining, part of gaseous diffusion barrier
type 2 pneuomocytes: round cells which secrete surfactant, capable of division
supporting tissue
fine reticular, collagenous and elastic fibres with some fibroblasts.
blood vessels
capillaries
