Histology Flashcards
what is phonation
making sounds
what is olfaction
smelling
what is the role of the nasal cavity
warming, moistening and filtering the inspired air
what cell type covers the roof of the nasal cavity
olfactory epithelium
what cell type lines the vestibule
keratinised stratified squamous epithelium
what happens to the epithelial cells as you descend deeper into the nasal cavity
lose keratin
describe respiratory epithelium
pseudostratified ciliated columnar epithelium with goblet cells
what is underneath the respiratory epithelium
the lamina propria
what is the lamina propria
band of connective tissue containing seromucous glands and a rich venous plexus
what parts are lines with non-keratinized stratified squamous epithelium and why
parts that transmit both air and food; oropharynx, anterior (lingual) surface and upper posterior surface of the epiglottis
what is the larynx made of and lined with
cartilage and muscle, respiratory epithelium
what are the vocal chords and adjacent structuers lined with and why
stratified squamous epithelium, not cilia
describe the cartilage in the trachea
c shaped. gap spanned fibroelastic tissue and smooth muscle
what is the respiratory epithelium backed by in the trachea
a basal lamina, a lamina propria of connective tissue with abundant elastic tissues, a submucosa- connective tissue with seromucous glands
what are the walls of the bronchus made up of
RE, lamina propria, muscularis (ring of smooth muscle), submucosa with adipose tissue and seromucous glands
what happens to the hyaline cartilage as you descend down the bronchi
rings become irregularly shaped cartilage discs
when is the cartilage fully lost?
when bronchi are about 1mm (bronchioles)
what happens to the epithelium as you descend down the respiratory tree
decreases in height from columnar to cuboidal
what are the terminal bronchioles
smallest bronchioles that lack respiratory function
what are the respiratory bronchioles
after terminal, bronchioles with respiratory function
what is the lamina propria of the terminal bronchioles made of
smooth muscle and elastic and collagenous fibers
what do the smooth muscles of the bronchioles respond to
parasympathetic, innervation, histamine and other factors
what are terminal bronchioles lined with
cuboidal ciliated epithelium and non ciliated club cells
what are the role of club cells
stem cells, detoxification, immune modulation, surfactant production
what cells composes the alveoli
discontinuous squamous type 1 and 2 alveolar cells
alveolar cells are also called
pneumocytes
describe type 1 cells
simple squamous epithelium
describe type 2 cells
polygonal, free surface covered by microvilli, dense membrane bound with lamellar bodies which contain surfactant
how is surfactant released by type 2 cells
via exocytosis
what does surfactant do and thus prevent
reduces surface tension of pulmonary surface which reduces tendency for alveoli to collapse
what are dust cells also known as
alveolar macrophages
where do dust cells reside
free cells either in the septa or migrating over the luminal surfaces of the alveoli
what is the role of the dust cells
to phagocytose inhaled particles that may have escaped entrapment by the mucous lining of the airway
where do dust cells migrate to
up the bronchial tree, transported by ciliary action, to the pharynx where they are swallowed or move into the septal connective tissue where they remain
what is the air blood barrier
the septa between alveoli permeated with capillary networks
what does the air blood barrier consist of histologically
type 1 cell, endothelial cell and the basal lamina of each
describe the outer layer of the visceral pleura
simple squamous epithelium called mesothelium backed by layers of fibrous and elastic connective tissues,
how does smoking affect cilia
paralyses them
how does smoking affect trachea epithelium
replaces it with squamous
what does the cartilage prevent
smooth muscle closing the airway
where is the alveolar duct located
at the end of the resp. bronchioles before alveoli
what almost always causes mesothelium cancer
asbestos
