Lung function 1, 2 and 3 Flashcards
The angiotensin converting enzyme in the respiratory system converts angiotensin I to what?
angiotensin II
What does angiotensin II do?
it is a potent vasoconstrictor that regulates blood pressure
What is the conducting zone of the respiratory system?
- it conducts air to and from the respiratory zone.
- Airflow to and out of lungs ( nose to terminal bronchioles)\
- Heat, hydrate and clean the air
- Heat exchange, water vapor pressure equilibration, and remove particulate load
- mucociliary clearance.
what is the respiratory zone in the lungs?
- important for gas exchange
- End of respiratory tree ( respiratory bronchioles, alveolar ducts, and alveolar sacs
- Gas- exchange surface
- epithelial layer and an extracellular matrix
- Surrounded by capillaries.
In the conducting zone what kind of flow exists?
bulk flow: air moves into lung during inspiration towards alveoli with bulk flow and then from the respiratory zone to environment via bulk flow. uses a pressure gradient.
In the respiratory zone, alveoli gas moves across the alveolar capillary membrane by…?
diffusion
oxygen moves from alveoli in high concentration to the blood where it is in low concentration.
carbon dioxide moves from blood stream in high concentration to the alveoli where it is in low concentration
what is the difference between bulk flow and diffusion?
bulk flow= different gas particles moving along a pressure gradient
diffusion= individual particles moving along a concentration gradient.
what does Fick’s law look at /
the rate of gas diffusion.
rate of gas diffusion= diffusion coefficient times surface area available for gas exchange/ diffusion barrier thickness ( pressure difference)
V gas= D A/t (P1-P2)
LOOK AT WALL.
Where does gas exchange occur in the lungs?
alveoli (75m^2)
what is the most extensive network of capillaries in the body?
pulmonary circulation
With a large surface area in Fick’s law, what is said about gas exchange?
there will be a large rate
The rate of gas diffusion in fick’s law is _________ proportional to the diffusion barrier thickness
V gas= D A/t (P1-P2)
t= diffusion barrier thickness and here you can see it is indirectly proportional. to the rate of gas diffusion.
what track does oxygen have to take to drivefrom alveoli to blood stream?
- thin surface fluid that lines the alveoli
- then alveolar epithelium cells ( type 1 pneumocytes) plus associated basement membrane
- Thin layer of interstitial fluid
- Pulmonary capillary endothelial cells, plus associated basement membrane
- blood stream where it binds to hemoglobin
What do type 1 pneumocytes/ alveolar cells make up?
make up alveolar wall and occupy most of the surface area
what do type 2 pmneumocytes/ alveolar clells make? What does surfectant do to surface tension in alveoli and lung compliance?
surfactant: important for reducing surface tension in alveoli and increase lung compliance.
compliance= ability to distend= important to accommodate air..
surfactant keeps lung dry and prevents pulmonary edema
main component is dipalmitoylphosphatidylcholine
Airway generation tree 0-16 represents what zone?
conducting zone
what do zone 0, 1, 2, 16 represent in the conducting zone? what kind of epithelium is found here?
0 The trachea, 1 bronchi, 2 and 16 are the bronchioles..
ciliated pseudostratified columnar epithelium with goblet cells
-the goblet cells make mucous
-have glands here/ make fluid to hydrate air
-cartilage maintain patency of airway
-alot more cilia
- have smooth muscle
- elastic fibers
bulk flow/heating hair/hidrating/cleaning it
what numbers represent the transitional/ respiratory zone?
17-23
what do 17, 19, 20, 22, and 23 represent in the transitional respiratory zone?
17 and 19- Respiratory bronchioles
20 and 22 Alveolar ducts
23 Alveoli
epithelium is thinner= simple squamous created by type 1 alveolar cells ( wall of alveoli)= increased gas diffusion cus of thinner walls.
- no cilia
- only see smooth muscle in both
- elastic fibers in both
what are some disease that effect the conducting zone?
airflow is affected; affected;obstruction
ventilation problems/ flow velocity problems,
asthma, COPD, bronchitis, bronchiolitis, cystic fibrosis ( viscous mucous)
what are some disease that affect the respiratory zone?
gas exchange is affected. The alveoli/lung/parenchyma
Gas exchange problems present with volume problems
Pulmonary fibrosis= hardening of the wall of the alveoli (including pneumocniosis) hypersensitivity pneumonitis, pneumonia
What is affected by smoking?
cilia, it affects the movement of mucous that traps foreign particles
what are serous cells important for?
hydrating the air and ensuring that the mucous is at the right level of viscosity.
how is someone with ciliay dyskinesia affected?
they will not be able to move the cilia towards the oralpharaynx
in what disease is mucous too viscous?
in cystic fibrosis
What is the clinical correlation of chronic bronchitis?
- inflammation of bronchi
- common from cigarette smoking
- number of goblet cells might increase and mucous glands may hypertrophy
- cilia movement is impeded
- increased mucous gland secretion and increased viscosity of mucus leads to coughing and obstruction.
- a cough with sputum expectoration for at least 3 months a year during a period of 2 consecutive years.
what is included in the superior structure of the thoracic cavity?
ribs and muscles of chest wall
what is in the most inferior structure of thoracic cavity?
diaphragm
More inward in the thoracic cavity is the pleura, what are the two membranes associated with it?
visceral= associated with lung
in between this is the pleural space.
parietal= associated with chest wall
what is inside the pleura ?
the lungs
what occurs when the diaphragm contracts?
it moves down during inspiration opening a space
what occurs when the diaphragm relaxes?
this occurs during expiration, it relaxes and moves upward
what law indicates the relationship between pressure and volume?
Boyle’s law
At constant temperature, as pressure increases volume what?
decreases
what does Charles law show?
relationship between volume and temperature in an ideal gas where the pressure is constant
what is the Charle’s law equation?
V1/T1=V2/T2
As temperature increases, the volume of the gasses…?
also increases
what is atmospheric pressure?
760 mm Hg
when the air pressure in the alveoli gets lower than the atmosphere, what occurs?
air moves from the environment into the alveoli
ex= Inspiration the pressure of alveoli in the lungs is -1 and the atomospheric pressure is 0 and you breath in
If the opposite is true, more alveolar pressure, than the lungs alveoli have +1 and the atmosphere has 0 at expiration
why does airflow?
because of pressure gradients.
what are the muscles involved in inspiration?
Diaphragm, external intercostal, scalene, sternocleidomastoid, pectoralis muscles, serrates anterior, Latissimus dorsi
what are the muscles involved in expiration?
Internal intercostal, Innermost Intercostal, Rectus abdominis, Transverse oblique, internal oblique.
