Quiz 4 Flashcards
simply what is an amphibian lung
simple sac with moderate surface area elaboration
what kind of pressure inflation do reptile lungs have
positive pressure
are amphibian or reptile lungs more complex
reptile are more complex
what kind of pressure dynamic do most vertebrate lungs have
most vertebrate lungs have a negative pressure system
what is a negative pressure dynamic
use bucal cavity to push air into lungs creating a positive pressure (bucal cavity contracts pushing air positively into lungs)
what animal has one functional lung
snakes within reptiles (other lung is vestigial)
how do reptiles compensate for exchange since the integument doesnt have any meaningful O2 exchange
have more sacculations in their lungs to increase surface area without necessarily creating a bigger lung
what is a faveoli
a sac within the lungs of reptiles
where is the most sacculation (faveoli) in the lungs of snakes
primarily in first 1/3 of the snakes lung (1st 1/3 cranially)
what does the last 2/3 of the snake lung act as
acts as bellows which activates pressure cycles
what is a bellows
an area that allows contraction or expansion
how does a snake lung act as a bellows
old air in last 2/3 of lung is pushed towards outward creating an inner pull for new air to come in
all amphibians have sacculated lungs, why
to increase surface area and increase gas exchange
what is a thoracic cavity
present in mammalian lungs, pleural space, drained by lymphatic system)
simply what are mammalian lungs
paired lungs with lobes
how is air modified before coming into the lungs
air is conditioned to make it wetter, warmer, and cleaner
where is the diaphragm
below the lungs
how many lobes does a human heart have
5
why is there no gas exchange on the conduction zone
its too thick
why is gas exchange possible in the respiratory zone
because of millions of microscopic bubble like alveoli
what does the respiratory tree begin with
trachea that is superior to the thoracic cavity
the respiratory tree has successive branching, what are the main types of branching here
generations and alveoli
how many generations are there in mammalian lungs
23 (0-16 conducting zone, 17-23 respiratory zone)
what causes branchiolar constriction
smooth muscle walls of middle passagewats
what was branchiolar constriction
reduced airflow
what kind of constriction is present in asthma
hyperconstriction
how many alveoli are in the lungs
300 million
when would you use nearly all of the alveoli
when exercising
what surface area does 300 million alveoli create
85m^2 surface area
why do overweight individuals have a higher chance of having asthma
adipocytes release lung imflammatory protein (fatter you are, 3x more protein released and inflammation causes asthma)
what promotes relaxation and increased airflow of bronchioles when having asthma attack
sympathetic division with epinephrine
when would the bronchioles change in diameter
when they are inflammed they close up (asthma), when theyre relaxed theyre open
as the diameter of the bronchioles increases, the resistence of fluid movement ….
decreases
what affects the fluid movement of air in the bronchioles
tubule length and diameter
what is the size of a single alveolus
300microns
the main wall of the alveolus is made of what kind of cells
simple squamosal
what are the type 1 epithelial cells
main all of alveolus
what are the type 2 epithelial cells
between successive alveoli, secretory mitochondria
what are secretory mitochondria
lamellated bodies
what do secretory mitochindria produce
surfactant (dipalmitoyl lecithin)
what does a lack of surfactant (dipalmitoyl lecithin) cause
can cause respiratory distress syndrome in children
what do fibroblasts do
build connective tissue
what do macrophages do
remove pathogens (defensive function)
what kind of cells are type 2 epithelial cells
cuboidal
whats the function of surfactant
reduces cohesion of water molecules, reducing surface tension
what is the function of fibrocartilage in alveoli
ribrocartilage helps to keep alveoli open so gas exchange can continue
what are ventilation dynamics
pressure volume changes (tissue fluid pressure in pleural cavity)
why is tissue fluid pressure in pleural cavity higher than lung pressure
without the pressure difference lungs can collapse (pneumothorax)
what is the pressure difference between pleural cavity and lungs during inhalation
3-4mmHg
what is the pressure difference bwteen pleural cavity and lungs during exhalation
1-2mmHg difference from exhalation
what is pneumothorax
when pressure between pleural cavity and lung is compromised, lung collapses and pleural cavity fills with air
what forces lungs to move involuntarily
diaphragm will be activated to contract
what direction do intercostals move
outward and up
how much CO2 is in the body at all times
about 40mmHg
how much CO2 is in the environment usually
about 100mmHg
is inspiration or expiration always an active process
inspiration is ALWAYS an active process
what are the types of volume changes
inhalation and exhalation
how does inspiration happen
cavity boundaries expand and lung follows
how does exhalation happen
cavity boundaries recoil, lungs follow
how can exhalation be active or passive
passive because elastic recoil can force air from lungs, active because muscles (intercostals, rectus abdominus) can force air out of lungs
what is anatomical dead space
the residual volume of air in lungs that cannot be forced out
how much oxygen is found in alveoli
100mmHg
how much oxygen is found in environment
160mmHg
what is the exchange time to equilibrate blood to lung air
about 1/4 of a second
what is the resting transit time to equilibrate blood to lung air
about 3/4 of a second
what is the exercise transit time to equilibrate blood to lung air
about 1/3 of a second.
equilibrating blood to lung air is a feature of which type of epithelial cells
type 1 epithelial cells
elephants lack a pleural cavity, how do they keep their lungs from collapsing
lungs are tethered open
what is west’s argument for elephant lungs being tethered open
evolved for snorkeling behavior, water compression would otherwise collapse the lungs
what is elasticity
readily recoils to original shape
what is compliance
stretches easily
when is elasticity and compliance opposite of each other
at extreme ends of the spectra (if excessively elastic then lose compliance and vice versa)
what are obstructive lung diseases
COPD and asthma
what is COPD
chronic obstructive pulmonary disease
how is COPD caused
cigarettes, volatile chemicals get in the middle of the respiratory tree and causes imflammation that can lead to emphazema meaning air cant get to alveoli because air tubing was blown apart, non reparable
what do obstructive lung diseases do
increase airway resistance
what do restrictive lung diseases do
increase elasticity of lungs
whats an example of a restrictive lung disease
fibrotic lung disease
how does fibrotic lung disease work
air bourse particles not being filtered out so they go in conductive or respiratory zone, tubercles are made in defense where fibroblasts trap off that part of the lung eventually reducing lung capacity
what does VC=
VC=TVr+IRV+ERV
what is vc
vital capacity
what is tvr
tidal volume resting
what is irv
inspiratory reserve volume
what is erv
expiratory reserve volume
what is vital capacity
maximum amount of air that can move through lungs
what is the typical total lung capacity
around 4-6L
what is vital capacity volume
3-5L
what is residual volume typically
1L
what is residual volume
excess air in lungs that cant be pushed out
what is tidal volume
amount of air moved in a breathing cycle
what is a typical tidal volume at rest
about 500ml
what is a typical inspiratory reserve
3L
what is a typical expiratory reserve
1L
inspiratory and expiratory each have their own ___ potantial
pacemaker
what is the purpose of increasing depth and rate of breathing for tetrapod vertebrates
maintaining hemoglobin saturation of O2 and CO2
what does branchiolar dialation do
lowers resistance
where in the brain is breathing controlled
medulla oblongata
what does the VRG of the medulla have
inspiratory and expiratory neurons
what does the DRG of the medulla have
modifies VRG activity
where does the pacemaker potention of inspiration and expiration happen
in the medualla
