Respiratory Flashcards
respiratory function
facilitate gas exchange
2 zones of respiratory system
conducting and respiratory
conducting zone
transport air from external environment into respiratory zone
respiratory zone
location of gas exchange b/w lungs and bloodstream
conducting zone components
nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles
respiratory zone components
respiratory bronchioles and alveoli
where does the transition b/w conducting and respiratory zone occur
the first alveolar outpouching (thin layer in histo slide)
alveoli
site of gas exchange
inhalation
active process
-expands volume of lungs
-involved thoracic cage, intercostal muscles, and diaphragm
what kind of fibers are store energy when stretched
elastic fiber store potential energy
relationship between volume and pressure
inversely
how does gas move in lungs
moves from areas of high pressure to low pressure
exhalation
passive process
-air gets pushed out by forces of recoil
ventilation
exhalation + inhalation
how is ventilation regulated
by chemoreceptors, mechanoreceptors, irritant receptors, nuclei in pons and medulla
nares
where air enters in the nose
conchae
where air enters after the nares
-provide resistance to slow air down, to wet it and humidify it
-pseudostratified epi
superior concha houses what
olfactory epithelium
goblet cells
produce mucus to trap debris and toxins
cilia
move particles to places where they can be disposed
metaplasia
initial change from normal cells to a different cell type
-columnar to squamous metaplasia
-caused by smoking
-potentially reversible if acute
what is cilia driven by
dynein
Primary Ciliary Dyskinesia (Kartagener’s)
-ciliary microtubules lack dynein
-cilia cant clear mucus in respiratory
-causes bronchitis and sinusitis
-sterility in men
mucus composition
-water and ion balance
-needs to be thick enough to trap particles
-needs to be thin enough for cilia to propel it along
cystic fibrosis
makes mucus more viscous
-mutation in CFTR
-defective Cl- channel
-more Na+ ions flow into cell causing water to go into cell
-causes dehydrated viscuous mucus
olfactory epithelium
fibers from CN 1, olfactory nerve, extends from receptor neurons to contact olfactory bulb
odorants
chemicals that interact with olfactory cilia that extend from the dendritic processes of cell body
Bowman’s glands
glands that produce serous secretions to help odorants bind to cilia
pharynx components
nasopharynx and oropharynx
nasopharynx epithelium
psuedostratified ciliated columnar with goblet cells
oropharynx epith
stratified squamous epi
larynx
cartilaginous structure held together by ligaments and CT
larynx function
-continues path of air in and out of lungs
-protects lower airway from food (epiglottis)
-making sounds
vocal folds
true and false vocal folds
true vocal folds
vibrations of these make sounds
-stratified squamous epithelium
false vocal folds
includes glands that lubricate strictures in the area
-typical respiratory epithelium
when breathing in, vocal chords
are seperated
during phonation, vocal cords …
are close together and their vibrations produce sound
what type of cartilage does trachea have
c-shaped hyaline cartilage
-cartilage keeps the airway open
what is trachea cartilage c-shaped
b/c food traveling down esophagus needs spatial flexibility
bronchial branching
progressive decrease in the diameter of channels and increase in their # of cross-sectional area
-SA is greatest when respiratory zone is reached
what does trachea branch into
right and left bronchi
lung hilum
where the bronchi become surrounded by lung tissue
bronchus characteristics
-irregular cartilage
-pseudostratified epi with goblet cells
-lamina propria
-smooth muscle
what spirals around bronchi and bronchioles
smooth muscle (bronchodilation and constriction)
brochioles
-no cartilage/glands
-epi changes from pseudo to ciliated columnar to simple cuboidal
-goblet cells replaced with clara cells
terminal bronchus
final structure of conducting zone
-last bronchioles with no alveoli
respiratory bronchioles
-simple cuboidal epi
alveolar ducts
respiratory bronchioles with continuous alveolar ducts
-aisles that numerous alveoli open into
-lead to alveolar sacs
alveolar sacs
spaces extending off alveolar ducts that numerous alveoli open into
alveolar structure
thin-walled structures build for efficient gas exchange
-walls with elastic fibers
-surrounded by capillaries
-pores of kohn for communication
Type I cell
simple squamous, gas exchange
Type II cell
synthesize and secrete surfactant, embedded in cell lining
alveolar diffusion barrier
-Type I cells
-capillary endothelium
-shared basement membrane
Type II surfactant
reduces surface tension in alveoli, ensuring walls wont stick together
emphysema
breakdown of elastic fibers in alveoli and bronchioles causes alveoli to form blebs
-causes airway collapse, hypoxemia, and hypercapnia
