Respiratory system Flashcards
what is the conduction and respiratory zones?
conduction zone only refers to ventilation areas —> area’s involved in the movement of air between the lungs and the atmosphere.
Respiratory zone refers to area’s of actual gas exchange i.e. respiration
Explain the effects of hyper and hypoventilation on blood pH.
CO2 converts to carbonic acid which creates an acidic pH in the blood.
If we hyperventilate, we are releasing lots of CO2 which increases the pH causing an alkalosis.
If we hypoventilate, we are allowing CO2 to add up which decreases the pH causing an acidosis.
explain the pathway of air to the lungs (conduction + respiration zone)
nose –> nasal cavity –> pharynx —> through the epiglottis into the larynx –> trachea –> primary bronchi –> terminal bronchioles –> respiratory bronchioles –> Alveolar ducts –> alveoli
what are columnar epithelial cells, simple squamous epithelial cells, and cuboidal epithelial cells? where are they found in the respiratory tract.
Within the conduction zone there are columnar epithelial cells which are too thick for gas diffusion to occur.
the alveoli are made up of two kinds of cells
Type 1 alveolar –> simple squamous and allows for gas exchange
type 2 alveolar –> cuboidal cells which secrete surfactant which reduces surface tension.
what is the mucociliary escalator system?
between the columnar cells of the conduction zone are goblet cells which secrete mucus (secretory cells are typically cuboidal like type 2 alveolar cells)
this mucous is swept by cilia on the columnar cells which accumulates by the pharynx to be coughed up or swallowed. This is an immune function.
true or false, alveolar type 1 cells secrete surfactant
false, type 1 are simple squamous which allow gas exchange.
explain the parietal pleura and visceral pleura. What is the pleural space?
each lung is surrounded by a pleural sac.
The inner layer of the sac is called the visceral pleura which lines the lungs. The outer layer of the sac is the parietal pleura which lines the chest cavity.
between the two layers is the pleural space
what is the main force which keeps the lungs open at all times?
the pleural space is always at a negative pressure. this negative pressure pulls the visceral pleura towards the chest cavities parietal pleura allowing the lungs to remain open
what would occur if the pleural space was punctured and exposed to air?
since the pleural space is always negative, air would rush into the space causing it to become 0 or +. now nothing is holding the lungs open and they will collapse.
what muscles control inspiration and expiration
inspiration: diaphragm descends and external intercostal muscles
expiration: relaxation of inspiratory muscles + (for forced exp.) internal intercostals
what happens to alveolar pressure and pleural pressure during inspiration?
- diaphragm and intercostals contract
- chest cavity expands
- Pleural pressure decreases becoming more negative
- alveolar pressure becomes negative
- air fills the lungs
as air fills the alveolar pressure becomes slowly more positive until expiration
what is FRC, VC, RV, and TLC?
FRC - functional reserve capacity. This is the amount of air left in your lungs after a normal expiration
RV - residual volume: air that always remains in lungs
VC - total volume of air we can inspire and expire (TV + IRV + ERV)
TLC - total lung capacity (VC + RV)
what would occur if the left atrium pressure increased a lot
blood would not be able to come back to the heart as easily. as a result, blood would be expelled from the pulmonary vein into the lungs giving a pulmonary edema.
A similar thing would happen if hydrostatic pressure in the pulmonary capillaries increased a lot.
true or false, gases become less soluble in water when temperature rises.
true! increased temp will decrease gas solubility in contrast to that of solids
what is Henrys law?
concentration of a gas in a liquid depends on the partial pressure of that gas and its solubility in the liquid
for our purposes, alveolar partial pressure = arteriolar partial pressure
