physiology 1/2 Flashcards
the 4 functions of the respiratory system are
Puppies In Snowy Garden
pH, Infection, Speech, Gas exchange
what direction dose the pulmonary artery go
Artery goes Away
A - A
what is the function of the pulmonary circulation
2
to deliver CO2 to the alveoli
to take O2 in the pulmonary veins back to the systemic circulation
how does this differ from the systemic circulation
2
the pulmonary circulation does not supply nutrients to the lungs
veins and arteries are the ‘‘wrong way around’’
when does speech occur
expiration
what is the average volume of oxygen exchanged a minute
250 ml
what is the average volume of CO2 exchanged
200 ml
where is URT/LRT divide
At the larynx after the vocal chords
why do healthy people at rest breath through their nose
2
don’t need excess air - don’t need mouth
nasal cavity warms and moistens air
where is the last point of NO gas exchange in the lungs
the terminal bronchioles
where is the first place of gas exchange where do these lead to
the respiratory bronchioles
the alveoli
what can contract to decrease airway diameter
bronchial smooth muscle
what happens when a airway is contracted
decreased diameter = increased resistance
what happens when a airway relaxes
increased diameter = decreased resistance
where is the most resistance to air flow
why??
the ‘‘conducting zone’’
(trachea, bronchi, bronchioles)
road analogy - big roads have lots of traffic where as small roads have less
what cells are present in an alveoli structure
type 1 pneumocytes
type 2 pneumocytes
endothelial cells of capillary, alveolar macrophages
what do type 1 pneumocytes do
make up the majority of alveolar cell walls
what do type 2 pneumocytes do
secrete the suricant that lines in the inside of the alveoli
what is anatomical dead space in relation to the respiratory system
space in which gas exchange cannot occur (i.e. the trachea, bronchi and bronchioles)
what role dose the mucosa play in the function of the respiratory tract? (3)
moistens air on inhalation
traps particles
larger area for cilia to act on (i.e macrophage escalator)
from what cells is mucosa produced
goblet cells
what is the name of your throat
pharynx
what small flap of tissue prevents food going down your trachea
epiglottis
what is the larynx
the voice box, contains vocal chords
what does Boyles law state
that the pressure exerted by a gas is inversely proportional to its volume
what is a pleural cavity
the space on the ‘‘inside of the balloon’’ between the visceral and parietal pleura
what is pleurisy
inflammation of the pleura
what pleural membrane toughs the lung
the visceral pleural membrane
what pleural membrane touches the ribcage
the parietal pleural membrane
what is inside the pleural cavity
intrapleural fluid
what is the function of the intrapleural fluid
to lubricate the lungs
what is the intrapleural pressure
P = -3 mmHg
COMPARED TO ATMOPHERIC PRESSURE
what direction dose the elastic recoil pull the:
- lungs
- chest wall
the elastin within the lung tissue means that the lungs want to recoil inwards
and the chest wall wants to spring outwards
what muscles are used for inspiration
Diaphragm
External (BREATH OUT)Intercostal
sternocleidomastoid (NECK - forced inspiration)
Scalenes (raise ribs 1 and 2)
what muscles are used for expiration at rest
NONE!!! in a healthy person
what muscles are used during forced expiration
internal intercostal muscles
abdominal muscles
what attaches lungs to the rib cage
the cohesive force between the two pleura due to the intrapleural fluid
what are the two ‘‘handle’’ motions of the ribs
Pump handle and bucket handle
what happens in a pneumothorax
when the intrapleural pressure (-3) is lost and the lung recoils to its unstretched size
what is P(A)
intra-thoracic alveolar pressure can be -VE or +VE compared to the atmosphere
what is P(ip)
intra pleural pressure can only be -VE
what is P(T)
it is always +VE as P(T) = P(A) - P(ip)
describe the pressure changes in the lungs during reparation
Pip decrease from -3 down during inspiration and back up to -3 during expiration
PA fluctuates from -VE to a plateau then +VE
going from inspiration to expiration
what happens when Patmos = PA
there is no air movement
what is the major determinant of airway resistance
the radii of the airways
what is the approximate volume of dead space (PER LUNG)
approximately 150ml
what is vital capacity
the MAX volume of air that can be shifted through a set of lungs
what is FEV1
Force Expired Volume over 1 second
what is the residual volume
the volume of air that cannot be expired
what is alveolar ventilation
the volume of fresh air getting into the alveoli - partaking in gas exchange
why is breathing only 70% efficient
due to the 30% of air in dead space
what does partial pressure state
what doses this lead to
the sum of gasses = the pressure of the atmosphere
PO2 and PCO2 being proportional to each other
what gas is one gas in the atmosphere we don’t breath in
CO2
what is the innate gas that we breath in - what happens
nitrogen
it does nothing, unless you get decompression sickness (the bends)
what is surfactant
a detergent like fluid that mikes the air in with it, produced by type 2 pneumocytes
what dose surfactant do
3
reduces surface tension on alveolar surface membrane
increases Compliance and breathing is easier
prevents alveolar collapse
where is surfactant more effective - why?
in smaller alveoli (nearer the top)
as the concentration is greater leading to more ‘‘mixing’’
when does surfactant production start/end - why is this important
starts at 25 weeks
ends at 36 weeks
premature baby might not have fully developed surfactant
what do premature babies develop due to surfactant production not being complete?
infant respiratory distress syndrome
what is high compliance
large lung volume increase for little P(ip) increase
what is low compliance
small lung volume increase for large P(ip) increase
in general what dose compliance suggest
the stretchability of the lung
what is Emphysema
loss of elastic tissue in the lung
requires more work on expiration
what is fibrosis
stiffer tissue that increase the effort of inspiration
lower compliance
'’string that stops the elastic band from expanding’’
where is the greatest change in lung volume in proportion to the change in P(ip)
at the base of the lung
what declines from base to apex of the lung
alveolar ventilation, compliance (due to being more compressed because of lung weight)
what is the difference in FRC between the alveoli in the base vs apex
the Functional Residual Capacity is higher in the alveoli in the apex due to their low compliance and lack of weight on them
what is FRC
Functional residual capacity is the volume of air left in the flung after passive tidal respiration
what is restrictive lung disease
restriction of lung expansion
what is obstructive lung disease - when?
obstruction of air flow - especially on expiration
what causes fibrosis tissue formation (2)
Idiopathic
Asbestos
what is a common lung function test
spirometry
what should a health FEV1/FVC be
80%
what is a fit healthy adult males FVC
what would the FEV1 be
Forced Vital Capacity = about 5 litres
about 4 litres
how can FEV1/FVC be misleading
restrictive lung disease can lead to the same percentage yet a lower volume
what is an adult males total lung capacity (PER LUNG)
approximately 3 litres each
which primary bronchi is slightly wider than the other
the right is wider shorter and slightly straighter
which si the first airway to loose their cartilaginous rings
bronchioles have no carilagnous rings
what goes between the alveoli/ normally in the interstisium - why
elastic fibres
increase recoil
why does inspiration occur
thoracic volume increases
alveolar pressure decreases
air rushes in = inspiration
during what stage of respiration is airflow resistance the greatest
during inspiration
what is the rough estimate for residual volume
1200ml
what is roughly tidal volume
500ml
when the word capacity is used
it means there are more than one volume combined
what is tidal volume
the volume of air breathed in and out after every breath
what is roughly the expiratory reserve volume
1100ml
what is the functional residual capacity
2300ml
what is the roughly inspiratory reserve volume
3000ml
what is roughly vital capacity
4600ml
what dose the graph of fibrosis look like
normal but long and stretched out
what does the graph of emphysema look like
a budge out the back showing extra work is required
what would obstructive spirometry be
worse % = 40
what would restrictive spirometry be
could be normal even good %= 90
jut not enough
