Respiratory 1 Flashcards
What is the breathing ?
Breathing is the process of oxygen and car-oxygen exchange between the atmosphere and body tissue
What are the steps of breathing
1-external breathing (exchange of gases between the atmosphere and lungs )
2-gases diffusion throughout aerohematic barrier
(Between alveoli and blood )
3-transport of gases
4-diffusion of gases through the capillaries walls
(Between blood and tissue)
5 - internal breathing , oxidative reaction in the cell ( mitochondria)
The first step of breathing done by ?
Lungs
Lung contents ?
-Alveoli
- airways ( bronchial tree ) includes
Tracheas
Bronchi
Bronchioles
Explain the Airways
airways ( bronchial tree ) includes
Tracheas
Bronchi
Bronchioles
- there is 22 binary fission generation of airways
-1- the first one is trachea division into two main bronchi
-2- the 16 generation is bronchi transferring to terminal bronchioles ( which don’t take a part in gas exchange)
-3- from the 17th binary fission generation respiration bronchi begin ,
up to the 19th generation there Are single alveoli
-4- the amount of alveoli increasing by each bronchioles division
When the amount of alveoli is increasing
Its increasing by each bronchioles division
What is the alveolar duct
Its the alveolar sacs that fully covering the 20-22 respiratory bronchioles divisions
What is the dead space ?
Dead space its space which there is no gas exchange reaction in the airway
Until the level of terminal bronchioles where its the dead space end and the gas exchange begin
What is the volume of the dead space?
150 ml
Why respiratory dead space was used to be called ” harmful “
Bcs it decreases the volume if the air involved in the gas exchange
What the significance importance of the respiratory dead space ?
Higher value in clinical situation for diagnostic and prognostic and therapeutic, through it we can messur the expired Co2
In normal condition what is active and what is passive ?
Inhalation , exhalation
Inhalation is active
Exhalation is passive
Explain the exhalation effector
Is implemented by graviton and elastic qualities of pulmonary parenchyma , that of airways and thorax
Forced inspiration and expiration are always active ? ( yes or no )
Yes
What is the pleural sac function
Its fundamental importance in implementation of inspiration and expiration mechanism
Explain the pleural sac ( pleural cavity ) pressure
In the pleural sac the pressure is always negative which is -4 mm hg
In other way Lung pressure ( inter pulmonary pressure) is equal the atmospheric pressure which is 760 mm hg
So while the lung trying to expands the atmospheric pressure is pushing and the pleural cavity in between them
What is the transpulmonary pressure
Its gradient of pressure between the pleural cavity and alveolar ( interpulmonary )
What is the thoracic pressure?
Its pressure between pleural cavity and atmospheric
What is the respiratory pressure ?
Its pressure between alveolar and atmospheric
What is the forces that control the movements or the pressure of the lungs ?
1 - the transpolmonary pressure which is always directed from alveoli to the pleural cavity from inside to out side and aims to expand the lungs
2 - the elastic recoil of the lungs
Which aims to compress the lungs
If these 2 forces are equal thats mean the lung doesn’t move
Explain the mechanism of inhalation
Start with reducing inspiratory mc , the pleural cavity expands and the it pressure get even more negative , transpolmonary pressure increases and elastic recoil of the lungs becomes greater , the lungs expands , air enters inhalation takes place
Explain the exhalation mechanism?
Its begins with relaxation of the inspiratory mc , in this case , due to gravity the thorax is lowered, pleural cavity decreases , and it pressure get even less negative , the transpolmonary pressure decreases and becomes less then the elastic recoil
And because id the action if the lungs parenchyma subside and exhalation takes place
How is elastic recoil created ?
- 1- first by the elastin of alveoli and bronchial tree
- 2- by cartilage tissue of the bronchi
- 3- and 2/3 of this force is created by a surfactant
What is the surfactant ?
Its a think layer of liquid , which the alveoli are covered from the inside
And bcs its liquid, it has the force of surface tension
And this force its the main component of the elastic recoil of the lungs
And the function of it to squeeze the lung on the other side it has low density and accordingly has low surface tension
If the surfactant had a water density , this would lead to a sharp increase in elastic properties and the lung would completely shrink ?
No , bcs the surfactant is liquid and its incompressible , this prevent the collapse of the alveoli at the most for ed expiration and adhesion of their walls
How o2 and co2 transported ?
By two ways
1-Free stats
2-connected states
What is the free states mean ?
Free states are physically dissolved species
Any gas can dissolved in the liquid ?
Yes
Explain the ways of transporting of o2
1- in dissolved form
2- in connection with Hb which named
Oxyhemoglobin
Explain the ways transporting of Co2
1- in dissolved form
2- in connection with Hb which named
Carbhemaglobin
3- in form fo acidic salts of carbonic acid
Ex: hydrocarbons and potassium and sodium
Why do we need free forms of gas transportation?
Bcs its necessary for gas exchange during the breathing duo the 2 and 4 stages of breathing are carried out
The bound forms can’t diffuse so they can’t participate in gas exchange
Also bcs the pressure
The free form when it’s dissolve its make partial pressure
And gases moves always from higher to lower partial pressure
Partial pressure how its created ?
Its created only by dissolving the gas in the liquid
If there is no dissolved gas there is liquid?
No
How gases moves betwen the pressure
They move from one medium to another but should be there is different in the medium
By simple way from higher pressure to lower partial pressure
When o2 dissolved in the liquid how much pressure created ?
O2- Arterial 100 mm hg
Venous -40 mm hg
Explain the gases moving
The difference in partial pressure of o2 between the alveoli and venous blood , as well as between arterial blood and tissue
Cussed the diffusion of the gas from the alveoli into the blood and from the blood into the tissue
What is the important component in the lung volume list much of practical significance
Vital capacity
Functional residual capacity
And its depends on the number of parameters
What can effect the VC and functional resdual
- Age ,especially after 40 years old owning to loss of the lung elasticity and increasing restriction of thoracic mobility
- sex : the average vc of women is smaller about 25% then the men
- size
- position of the body
- trained people
what is the main component of elastic recoil of the lungs
and what is function ?
the surface tension
its function to squeeze the lung
