Respiratory Zone Flashcards
What is the entire process of gas exchange in the body?
Pulmonary ventilation
External respiration
Internal respiration
Gas transport
Where does external respiration occur?
Between the lungs and blood
Where does internal respiration occur?
Between blood and body tissues
What changes volume and pressure in the thoracic cavity and lungs?
Contraction and relaxation of respiratory muscles
What is used to move air?
A pressure gradient
How does pressure move in respiratory system?
High to low
What is the main respiratory muscle?
The diaphragm
What is the diaphragm innervated by?
Right and Left phrenic nerves C3,4,5
Diaphragm gets ___ when it contracts?
Flat
Where does diaphragm attach to?
Sternum
Last 6 ribs
costal cartilage
lumbar vertebrae
What are the respiratory muscles?
Diaphragm
External Intercostals
Internal Intercostals
Transversus thoracis
Which muscles are used for deep exhalation only?
Internal intercostals
Tranversus thoracis
As pressure increases volume ?
Decreases
What are the steps to normal inhalation?
Respiratory Muscles contract
Volume increases
Lung pressure decreases
Air moves in the lungs
Step 1: Respiratory muscles contract
Diaphragm flattens
External Intercostal muscles lift the rib cage and parietal pleura pulling on the lungs
Step 2: Volume increases
Thoracic cavity expands as it pulls on parietal pleura, which pulls on visceral pleura, which pulls the lungs outward
What are the steps to normal exhilation?
Inspiratory muscles relax
Volume decreases
Lung pressure increases
Air moves out the lungs
Step 1: Inspiratory muscles relax
Diaphragm becomes dome shaped
Ribs return to original position
Step 2: Volume decreases
Ribs return to original position which push on the lungs
What is Tidal Volume (TV)?
Amount of air moved in a single normal breath (inhilation and exhalation)
What is inspiratory reserve volume (IRV)
Air volume you can take in above TV during FORCED inhilation
What is expiratory reserve volume (ERV)?
Air volume you can exhale past TV during FORCED Exhalation
What is residual volume (RV)?
Air volume remaining after forced exhalation
Cannot be measured by spirometry
Volume of air that lingers in your respiratory system
What happens in forced inhilation?
Increased thoracic cavity volume and decreased internal pressure pulling more air into lungs
What are the kinds of forced inhilation and exhilation
Chest breathing
Belly breathing
What happens during chest breathing? (inhilation)
Maximal contraction of the external intercostals pulls ribs superior
Sternocleinomastoid and scalene muscles pull ribs 1 and 2 superior
Erector spinae extends the vertebral column to straighten thoracic curvature
What happens during belly breathing? (inhilation)
Maximal contraction of the diaphragm to push diaphragm inferior
What happens in forced exhilation?
Decreased thoracic cavity volume and increasing internal pressure pushing more air out the lungs
What happens during chest breathing? (exhilation)
Contraction of the internal intercostals and transverse thoracis moves ribs infeiror
What happens during belly breathing? (exhilation)
Contraction of the rectus abdominis and lateral hypaxial muscles to compress abdomen and push diaphragm superior which flattens the belly
What is inspiratory capacity (IC)?
Tidal volume + inspiratory reserve volume
How much you can inhale
What is functional residual capacity (FRC)?
Expiratory reserve volume + residual volume
Volume of air that you can exhale
What is vital capacity? (VC)
Expiratory resserve volume + tidal volume + inspiratory reserve volume
All the air you can inhale and exhale
What is total lung capacity? (TLC)
Vital capacity + residual volume?
How much volume your lungs have in total
Describe restrictive diseases
Damage to pleura, lungs, or chest
Lungs cannot inflate completely
Decrease VC, RV, FRC, TV, and TLC
Describe obstructive diseases
Lungs inflate but cannot deflate due to obstruction
Increase RV and FRC because air is in the lungs for longer periods
What are pulmonary function tests used for?
Test for obstructive or restrictive lung diseases
What are the pulmonary function tests?
Forced vital capacity (FVC)
Forced expiratory volume (FEV)
What is forced vital capacity? (FVC)
Maximal inhale then rapid force exhale
What is forced expiratory volume? (FEV)
A percentage of the FVC that can be exhaled within 1,2,3 seconds
How to know if you have an obstructive disease?
Low FVC
Low FEV 1
Low FEV1/ FVC < 80%
How to know if you have a restrictive disease
FVC and FEV1 are lower than normal
but FEV1 /FVC = 80%.
Where does gas exchange start?
respiratory bronchioles
Where is respiratory zone?
Lobules
Describe respiratory bronchioles
First structure of the respiratory zone
Send air to lobule
What is true about lobules?
Each lobule is an alveolar duct and alveolar sac
What do alveolar sacs contain?
Several alveoli that are the main surface for gas exchange
What are alveoli made of?
Single layer of simple squamous cells
What are the types of alveolar cells?
Type 1
Type 2
Type 3
What are type 1 alveolar cells?
Thin flattened cells where gas exchange occurs
Makes up the respiratory membrane
What are Type 2 alveolar cells?
AKA Septal cells
Secrete surfactant which helps prevent the collapse of alveoli
What are type 3 alveolar cells?
Alveolar macrophages
Immune cells of the lungs
What does respiratory membrane consist of?
Type 1 alveolar cells
endothelial cells of pulmonary capillaries
External respiration
Blood has low O2 while air has higher O2 which favors movement of O2 from lungs into blood
Blood has high CO2 while air has lower CO2 which favors movement of CO2 from blood to lungs
Internal respiration
Tissues have high CO2 while systematic capillaries have low CO2 favoring movement of CO2 from tissues into the blood
Cells use oxygen constantly so there is low O2 in tissue, while systemic capillaries have high O2, favoring the movement O2 from the blood into tissues
How is oxygen transported?
In blood plasma by hemoglobin
What are the ways to transport carbon dioxide?
70% In the blood as Bicarbonate (HCO3-)
20% binds to hemoglobin as carbaminohemoglobin
10% dissolved in the blood
What determines the ph of blood?
Carbon dioxide
What does more CO2 in blood mean?
Lower blood PH
Less than 7.35
Respiratory Acidosis
Homeostatic response to respiratory acidosis
Common corotid and aortic arch chemoreceptors send message to medulla oblongata
Increased breathing rate and depth occurs
What does less CO2 and more O2 in blood mean?
Higher PH
More than 7.45
Respiratory Alkalosis
Homestatic response to respiratory alkalosis
Common carotid and aortic arch chemoreceptors send message to medulla oblongata
Results in decreased breathing rate and depth
