Respiratory Flashcards
What are the four major functions of the respiratory system?
- gas exchange such as oxygen and carbon dioxide between the blood and the atmosphere
- regulation of body pH - H+ + HCO3- —-> H2CO3 —->CO2 + H20 - works with blood buffers and kidneys
- Protection from inhaled pathogens and irritants - this can be viruses and bacteria and other pathogens
- Vocalization - through vibration of vocal cords in the larynx
How is pH regulated by the kidneys, lungs, and blood buffers and on what time scales do they work?
kidneys - all the time - get rid of bicarbonate and H+
lungs - blow off CO2 - minutes
blood buffers - seconds and sequester charged species
We have two lungs one on each side which lung is bigger?
right is bigger than left cause left needs to make space for heart
What are the three lobes of the lungs?
superior, middle, and inferior lobes
What are the total number of orders of brinchi branching?
23 orders of branching into bronchioles which terminate in alveoli
What causes bronchodilation and constriction?
smooth muscle surrounding the bronchioles
What are the bronchioles reinforced by?
c shaped cartilaginous rings
What does a type i alveolar cell do?
gas exchange is only one epithelial cell thick
What does a type ii alveolar cell do?
make surfactant and mucus
What happens to the chest wall when you inhale versus exhale?
chest wall moves outward when you inhale and moves inward when you exhale
Where do the lungs sit?
inside the pleural cavity
What is the distance between an alveoli and red blood cell?
one micron or 0.5 micron and this is due to interstitial fluid
What is around the alveoli?
alot of blood vessels and capillaries for gas exchange
What are the three types of fluids in nature?
gases liquid or plasma
How does fluid move pressure gradient wise?
from high to low pressure
What characterizes flow or Q?
Q is directly proportional to the delta P and inversely to R
What can cause resistance?
the friction of the fluid moving against the wall of the capillaries and turbulence which dissipates energy
What is Dalton’s Law?
the total pressure of a gas mixture is the sum of the partial pressures
What is Boyle’s law?
P1V1=P2V2 - pressure and volume are inversely related
What is the tidal volume?
the air going in and out during quiet breathing and tends to be 500-750mL
What is the inspiratory reserve volume?
the maximum inspiration not counting the tidal volume inspiration - 2L
What is the expiratory reserve volume?
the maximum expiration not counting the tidal volume expiration - 1L
What is the residual volume?
The volume remaining in the lungs post maximum expiration due to the elastin proteins and surface tension in alveoli keeping the lung from completely compressing
What is the vital capacity?
the IRV + ERV + TV
What is the inspiratory capacity?
IRV + TV - max amount of air you can stuff in the lungs
What is the functional residual capacity?
ERV + RV - air left in the lung during quiet breathing
What is the total lung capacity?
IC + FRC or the total of everything
What is the FEV1?
force expiratory volume in one second - how much air is moved out in first second
What is the FVC?
forced vital capacity is the total amount of air you exhaled
What does the FEV1/FVC ratio show?
-if it is greater meaning the FEV1 is bigger than the FVC - restrictive disease because lungs are not as compliant
-if it is smaller meaning that the FEV1 is smaller than the FVC then obstructive disease cause airways are blocked
What happens in a pneumothorax?
Puncture in intrapleural space so the lungs collapse air gets trapped there and the chest expands and IP pressure decreases more
Understand this graph
Inspiration Occurs when Alveolar Pressue Decreases cause Lung Volume Increases
-when the diaphragm contracts it drops towards the abdomen the ribs and pulled upwards and outwards during inhalation
-negative numbers are sub atmospheric pressure and positive numbers are above atm
-in brief pause between breaths teh alveolar pressure is 0mmHg like the air causing not net flow of air
-during inspiration the increase in thoracic volume leads to a drop in alveolar pressure which is now -1mmHg and air flow into the alveoli - because thoracic volume changes faster than air can flow the alveolar pressure reaches its lowest volume about halfway through inspiration
-as air continues to flow into the alveoli pressure increases until the thoracic cage stops expanding just before the end of inspiration - air flow will continue intil pressure inside the lungs equals the atm —– at the end of inspiration the air volume in the lings is at the max and the pressure in alveoli equals taht of the outside environment
Expiration occurs when alevolar pressure increases because lung volume decreases
-at end of inspiration somatic MNs stop impulses in inspiratory muscles and air pressure increases and reaches a max of about 1mmHg and since the alveolar pressure is higher than the outside the air flows out until 0mmHg is reaches again and the outside equals the inside
Intrapleural Pressure Changes during Ventilation
-the intraplerual pressure between the pleural membranes is subatmospheric
-the combination of the outward pull os the thoracic cavity and inward pull of the elastic recoil of the lungs creates an IP of -3mmHG
Pneumothorax -collapses lung due to air flowing into IP when punctured causing thorax to inflate and lung to collapse
Intrapleual pressure during respiratory cycle
-as the inhalation is occurring the lungs move with expsanding thoraci cavity but the cinnectuve elastic recoil of the kings increases causing the IP to become more negative -6mmmHG and then during expiration it returns ti -3mmHG
-IP pressure never equilibriate with the atm because it is closed off