3 - respiratory system Flashcards
differences between right and left lung
right lung: shorter + wider than left, 3 lobes
left lung: 2 lobes
lung: functions
air conduction
air filtration
gas exchange
conducting portion: characteristics
- respiratory epithelium - ciliated pseudostratified columnar epithelium
- cartilage + smooth muscle
respiratory portion: characteristics
- gas exchange
- simple squamous epithelium
- type I and II pneumocytes
conducting portion: structures
extrapulmonary - nose, pharynx, larynx, trachea, primary bronchi
intrapulmonary - secondary bronchi, tertiary bronchi and terminal bronchioles
respiratory portion: structures
respiratory bronchioles
alveolar ducts + alveoli
Cells of conducting portion
- ciliated columnar cells
- mucous goblet cells
- brush cells
- basal cells
- small granule cells `
nasal cavity: components
vestibule: hairs, stratified squamous epithelium & sebaceous glands
nasale fossae: roof, floor and internal nares - olfactory mucosa
nasal conchae: function
increases surface area and creates turbulence
turbulence: allows air to come into contact with lamina propria & conditions air
nasale conchae: parts
superior, middle, inferior
conditioning of the air
warmed
moistened
filtered
turbulence
nasal epithelium: olfactory epithelium
- cell types: supporting cells, basal cells, olfactory neurons
olfactory receptors
dendrites + cilia - respond to odours and generate receptor potentials
sense of smell - odours solubilised in mucous, odour-binding molecules transport to olfactory receptors
nasopharynx: epithelium
near soft palate: ciliated pseudostratified columnar epithelium
remainder: non-keratinised stratified squamous
`larynx: epithelium
vocal cords: non-keratinised stratified squamous
remainder: ciliated pseudostratified columnar epithelium
trachea: structure
- cricoid cartilage
- bifurcation: divided into 2 branches
- short flexible air tube
trachea: layers
respiratory mucosa - ciliated pseudostratified
submucosa
cartilaginous rings - hyaline cartilage, trachealis muscle + fibroelastic tissue
adventitia
trachea: functional histology
- pseudostratified ciliated columnar epithelium
- goblet cells
primary bronchus
- cartilage plates
- more simplified epithelium
secondary bronchus:epithelium
- lined with ciliated pseudostratified epithelium
terminal bronchiole - changes
cartilage replaced with smooth muscle
bronchus -> bronchi: changes
branching
irregular cartilage - plates instead of rings
smooth muscle: continuous layer in larger bronchi + loosely organised in smaller bronchi
lamina propria - mucous + serous glands, elastic fibres
changes in epithelium from bronchus to bronchioles
pseudostratified simple columnar low cuboidal lose goblet cells lose cilia
larger vs smaller bronchioles
larger: pseudostratified ciliated columnar
smaller: cililated simple columnar to cuboidal
clara cells
secrete surfactants
prevent collapse of bronchioles
produce p450 - detoxify harmful components
terminal bronchioles
ciliated columnar cells
clara cells
smooth muscle
elastic fibres
respiratory bronchioles: mucosa
low cubodial epithelium
parts with no cilia
opens up to alveoli pockets - simple squamous epithelium for gas exchange
alveoli
gas exchange between air and blood
surrounded by capillary network
simple squamous epithelium
alveoli wall: thick vs thin sections
thick: CT cells between basal laminae + CT fibres for support
thin: respiratory epithelium, fused basal laminae, gas exchange
type I pneumocytes
simple squamous
pinocytotic vesicles
gas exchange
95% of surface area
type II pneumocytes
secrete surfactant: reduce surface tension
5% surface area
cuboidal cells
alveolar macrophages: location
interior of alveolar septum + surface alveoli
alveolar capillaries
thin
nuclei bunched
efficient gas exchange
conducting portion: functions
- conduit for air travel to + from lungs
- conditions inspired air
