CVR Flashcards
upper respiratory tract components
nasal cavity
pharynx
larynx
lower respiratory tract components
trachea
bronchi
lungs
function of the nasal cavity
- olfaction
- respiration
- humidification of inspired air
- filtration of dust
- immunological role- trapping and removing pathogens
boundaries of the nasal cavity
roof
floor
lateral wall
medial wall
pharynx
pharyngeal muscles
- constrictors
-innervated by CNX
- longitudinal
-innervated by CNX
-stylopharyngeus innervated by CNIX
paranasal sinus
- frontal
- sphenoidal
- ethmoidal - has 3 (smaller)
-anterior
-middle
-posterior - maxillary
trachea
connection of the larynx to the bronchi
surrounded by c-shaped cartilaginous rings
bronchi
primary lobar bronchi
-right shorter, wider, more vertical
secondary lobar bronchi
-superior, middle, inferior
tertiary lobar bronchi
-10 bronchopulmonary segments
bronchial tree
tubular structures - continuously divides + get smaller
conducting airways only move air, no gas exchange
resp airways - where gas exchange occurs
ends at the alveolar sacs
eventually loses cartilaginous support
smooth muscles surrounds bronchioles
alveoli are surrounded by capillary networks
lungs
- site of gas exchange
- sit within the pleural cavity surrounded by the pleural membrane
-parietal and visceral pleura
3 lobes of the right lung
superior
middle
inferior
hilum of the right lung features
bronchi
pulmonary arteries
pulmonary veins
left lung features
2 lobbes
smaller - due to space taken up by the heart
lingula
hilium of the left lung features
bronchi
pulmonary arteries
pulmonary veins
thoracic cage function
breathing
protection
conduit for other structures
ventilation
intercostals
-external, internal, innermost
vent - musculature
- expansion of thoracic cavity
- decrease in intrathoracic pressure allows the influx of air to the lungs
- increasing intrathoracic pressure allows exhalation
define partial pressure
pressure exerted by a gas within a mixture of gases
EG. CO2
what is dalton’s law
sum or partial pressures for all gases in a mixture = total pressure
what are the variables of partial pressure
number of molecules of the gas, volumes, temp
what is diffusion
gases travel from areas of high conc to low conc
down a partial pressure gradient
why is dead space important
-useful to know how much inspired air actually participate in gas exchange
-need to know how much doesn’t go into Vd and subtract it
-gives idea of alveolar volumes
partial pressure is dependant on ….
elevation above sea level
the trachea is ……. cartilage
horse-shoe shaped
function of trachea
protects the windpipe (trachea)
prevents inward collapse
cartilage is not present in ……
bronchioles
bronchioles
mucosal
which cells secrete mucus
which cells secrete mucus
working out partial pressure
fraction that gas represents x total pressure
alveolar and arterial O2 are maintained at ……
equilibrium
how is the trachea kept clean
airways are mucosal tissues
goblet cells secrete mucus
dirt/pathogens trapped and expelled by movement of cilia
problems : smoking
what is the connection between lungs and thorax
chest wall and lungs are elastic
pleural cavity contains pleural fluid that can’t expand
fluid linkage - JOINS TOGETHER
so when the chest wall moves so do the lungs
explain the elastic recoil of the lungs
pull inwards and chest wall pulls outwards
at rest creates a negative pressure in the pleural cavity
lung volume under these conditions = FUNCTIONAL RESIDUAL CAPACITY
how to calculate lung distending pressure
Pressure inside (P lower in)- Pressure outside (P lower out)= lung distending
chest wall/lung distending pressure
Pressure inside (P lower in) – Pressure outside (P lower out)
describe breathing in / inspiration
- diaphragm contracts- downward pull
- major inspiratory muscle respornsible for quiet breathing
- other muscles utilised during eg. excercise, coughing
- volume of thorax and lungs INCREASE
describe boyle’s law
when the volume increases
pressure decreases
which two functional units are the airways divided into
conducting zone
repiarotry zone
explain breathing out / expiration
- diaphragm, relaxes- upwards push
- other muscles more important durig forces breathing beyogng FRC to redidual volume
- volume of thoarx and lungs decreases
- pressure in the lungs increase
airflows from a high prssure to low pressure
conducting zone
move,ent of air to gas exchanging regions
inspired air warmed and humidified
respiratory zone
presence of alveoli
gas exchange
desrcibe the movement of gases in the functional units
- conducting zone- bulk flow
- respirtory zone- branching INCREASES cross-sectional area, speed of flow DECREASES
how to calculate total flow
speed (decreases) x area (increase) - therefore unchanged
what does diffusion require
airflow - inspired air entering alveoli
blood flow - via pulmonary capillaries
how is boyle’s law expressed
P ∞ 1/V
what is the pressure in the pleural cavity at rest
negative
what does the negative pleural pressure in the pleural cavity at rest
what does the negative pleural pressure in the pleural cavity at rest
what is the figure for functional residual capacity
2.5L
what are problems of the trachea + primary bronchi keeping clean
problems: smoking- ciliary arrest, asthma/inflammation- increased viscosity mucous
what does the big gradient between blood + tissues do
drive oxygen down the latter
