intro to respiratory Flashcards
whats the main function of respiratory system?
Respiratory gas exchange
how is gas exchange rate determined?
O consumption and CO2 production ratio
so change in this ratio affects the gas exchange rate
how is respiratory coefficient affected?
die
what are the other functions of respiratory system?
1- Acid base balance
2- Metabolic function ( ACE enzyme production , uptake of biogenic amines, removal of prostaglandins )
3- Blood filter and reservoir ( cuz 100% of co goes to the lung )
4- body temperature ( not in human)
5- Elimination of volatile substances )
7- phonation
whats the anatomy of the respiratory tract from up to down?
1- Nasa cavity
2- pharnyx
3-larynx
4- trachea
5- bronchus
6-bronchioles
7- alveoli
whats the difference between right and left lungs?
Right lung –> 3 lobes
wider and more vertical and shorter
Left lung –> 2 lobes
narrower
whats the function of conduction zone?
responsible for transporting air from outside to inside
Cleans and humidfies and warms the air because cold could damage the lungs tissue
whats the function of respiratory zone?
its the site of exchange
whats the function of the cartilage in trachea and bronchi?
keeps the airway open
what happens when your born and when you grow to the respiratory system?
from birth to 8 years the number of the alveoli increases a lot
as you are growing the alveolar surfaces increase
what forms alveolar wall?
- Type 1 cell
- Type 2 cells
- Capillary
- Fibroblasts
- Pore of kohn
- Macrophages
-Thin wall
-Thick wall
describe type 1 cells?
Squamous epithelial cells joined to other type 1 or type 2 cells
how are the pneumocytes connected together?
tight junctions
describe type 2 cells?
Large cuboidal cells with LAMINAR bodies that produce surfactants
what are the 2 functions of type 2 cells?
1- surfactant production
2-stem cells in case of injury and become type 1 cells if needed
where do the capillaries come from?
branches of pulmonary artery
what also happens in the capillaries in alveolis?
Site of conversion of ang 1 to ang 2
- synthesis of hormones and degradation
whats the function of fibroblasts?
Source of elastic and collagen fiber
whats the function of elastic and collagen fibers?
Elasticity of bronchi
Keeps the small bronchi and bronchioles open because they dont have cartilage
describe pore of kohn?
small pore in the septum
whats the function of pore of kohn?
keeps the pressure same in all the alveoli cells
where are the macrophages located?
septum of alveoli and lumen
whats the function macrophages?
engulf foreign materials and sometimes called dust cells and phagocyte the rbc during heart failure
whats the function of the thin wall in alveolar wall?
optimal for gas exchange
whats the function of the thick wall in the alvolar wall?
provide structural stability
whats the general layers of the alveoli wall from outside to inside?
1- Alveolar air
2- Fluid layer ( surfactant )
3- Alveolar epithelium
4- fused basement membrane (Interstitial space)
5- capillary endothelium
6-capillary plasma
7- RBC membrane
8-RBC cytoplasm
whats the fused basement membrane which is also called interstitial space
the fusion between the capillary endothelium and alveolar epithelium
whats alveolar epithelium mainly formed from?
Type 1 cells
whats the blood supply of the lungs?
the pulmonary circulation
describe pulmonary circulation?
deoxygenated blood from the heart goes to the lung via pulmonary artery
the pulmonary artery ends at the alveolar capillaries where it becomes OXYGENATED BLOOD
The pulmonary circulation has 100% of co because blood from the heart directly
what do the pulmonary arteries accompany?
the bronchi and bronchioles and divide with them
where do the pulmonary veins run?
they DO NOT PARALLEL THE ARTERIES
they travel in the connective tissue between PULMONARY LOBULES
whats the function of pulmonary lymphatics?
Very important for draining the excessive interstitial fluid and keeps the lung dry
where do the pulmonary lymphatics run?
like p- veins they run between c.t and pulmonary lobules
how is the bronchi and trachea supplied?
bronchial circulation
Because the cells are far from the oxygen and cant oxygen by diffusion
describe bronchial circulation
gets a branch from the left heart side and capillaries and these will end in the adventitia of the bronchi
less than 5% of the co
where do the arteries of the bronchial circulation come from?
branches from the aorta and travel to the adventitia of the bronchi as capillaries
where do the veins of the bronchial circulation veins come from?
the capillaries will EMPTY DIRECTLY TO PULMONARY VEINS
whats the problem that happens in bronchial circulation
some of the deoxy blood that come from the bronchi will go to the pulmonary veins which has oxy blood so this produced a SHUNT
but its insignificant
what are the 3 processes by which respiration is accomplished?
Ventilation
Perfusion
Diffusions
Describe ventilation ?
Mechanical process by which air is supplied to the lungs a portion of the total ventilations goes to dead space ( conducting tract and ineffective alveoli )
describe perfusion?
process by which blood is supplied to the alveoli
portion of the perfused blood bypasses ventilated alveoli and is to said to be shunted ( bronchial circulation)
describe diffusion?
process by which respiratory gases are exchanged between alveolar air and pulmonary capillary blood
Resulting in O2 in the blood and removal of co2 from blood
whats daltons law?
in a gas mixture the total gas pressure is equal to the pressure of all individual pressures combined
PB =PN2 + PO2 + PH2O + PCO2
whats partial pressure?
pressure that is exerted by individual gases alone
PO2 = PB + FO2
Pressure = barometric pressure + concentration of the gas
whats the main composition of air?
Nitrogen ( 79%)
oxygen ( 21%)
what do we ignore in the air that is outside and dry?
Water vapor
CO2
when do we start considering water vapor?
when it gets inside the body it becomes important and we count it
whats the partial pressure of oxygen?
160 –> air (outside )
150 —> trachea
100 —>alveoli
100—> arteries
40—> mixed veins
whats the partial pressure of CO2
0–> Air ( outside )
0—> trachea
40—> alveoli
40–> arteries
46–> mixed veins
whats minute ventilation ? (expired minute ventilation )
is the amount of air that enter/exit the lung per minute
how to calculate minute ventilation?
expired ventilation = tidal volume ( air volume entering and existing the lung ) x frequency of breathing
Ve = Vt x f
whats alveolar ventilation?
amount of fresh air reaching the alveoli per minute ( you have to exclude the dead space air that doesnt reach )
how to calculate alveolar ventilation?
alveolar ventilation = (tidal volume - dead space volume) x breath frequency
Va = ( Vt - Vd ) x f
whats velntilation/perfusion ration?
pulmonary blood flow
this measures how much air supplies the alveoli before it reaches the blood flow for example ratio of 23% this means that 23% of the air supplies the alveoli b4 reaching the blood
whats anatomical dead space? ( Vd)
the air that stays in the conducting airway and is not used in gas exchange
how to calculate anatomical dead space?
Tidal volume = anatomical dead space + air reaching alveoli
Vt = Vd + Va
Vd = Vt - Va
whats alveolar dead space? Alveoli Vd
air that goes to non functioning alveoli and is not used in gas exchange
whats physiological dead space?
physiological dead space = anatomical dead space + alveolar dead space
Physiological Vd = anatomical Vd + alveolar Vd
how to calculate dead space ventilation?
dead space x frequency
whats the most effective way of increasing alveolar ventilation?
increasing the depth of the breathing which will also increase the tidal volume and not the frequency
whats borh equation ?
when air is moved out any CO2 in the air exhaled came from the alveoli that were ventilated so CO2 in the blood )
how to calculate the physiological deadspace?
physiological dead space = Tidal volume x ( PCO2 in blood - PCO2 in exhaled air )/ PCO2 in blood
PCO2 in blood
why is outgoing co2 is usually higher than incoming o2?
because of deadspace not all o2 reaches the alveoli and blood
whats fowlers test?
measurement of anatomical dead spaces
whats a cough reflex?
bronchi and trachea got irritated by foreign so they use this reflex to get rid of the foreign material
Larynx and carina and terminal bronchioles are also sensitive but to gases and chemicals
how are the 3 components of the cough reflex?
afferent nerve
central control
efferent and effects
whats the afferent nerve of the reflex cough?
Vagus nerve
whats the central control?
medulla of the brain
describe the effects?
2.5 liter of air is inhaled
Epiglottits close
abdominal muscle contracts forcefully with the intercostal muscles to increases the pressure and build it up
Epiglottis open suddenly under the pressure
Strong compression of the lung and trache and bronchi they narrow the airway
Air leaves at incredibly fast speed
whats the sneeze reflex?
similar to cough except its due to irritations of the nasal passageway not lower respiratory passages
whats the afferent nerve of sneeze reflex?
5th cranial nerve
whats the effect of sneeze reflex?
uvula depresses and large amount of the air pass through to the nose and clear out the passage and get rid of any foreign matter
