Week 9- Respiratory system Flashcards
Describe the functions of respiratory system
Pulmonary gas exchange
Controls Ph of blood
vocalization
cleans inspired air
Describe function and structure of alveol
Pulmonary gas exchange occurs here
Structured like a clump of balls all together
grapevine ish
type 1 cells function
simple squamous- thinnest layer
allow for exchange of gases
type II cells function
secrete surfactant (protein)
alveolar macrophages function
phagocytes that protect alveoli
What is the purpose of surfactant?
decrease surface tension which prevents alveoli from collapsing
What can happen if there is no surfactant?
collapsed lung
alveoli will collapse/close- causing no air to get in or out
Boyle’s law
Increased volume= decreased pressure
Decreased volume = increased pressure
inhalation-
Diaphragm will contract- will straighten and pull lung tissue down with it
increased volume of lungs= decreased pressure,
air outside of lungs is forced into lungs to equal out pressure
Exhalation
diaphragm will relax
decrease volume in lungs-increase pressure
air is forced out of lungs b/c of changes in pressure
what nerve innervates the diaphragm?
phrenic nerve
Describe how compliance can affect ventilation
ability of lungs to stretch(allow in) and recoil(allows air out)
Too high- cant recoil to let air out
Too low-cant stretch to let air in
Describe how airway resistance (including sympathetic and parasympathetic effects ) can affect ventilation
Para- increase resistance by contracting airways (decreases diameter)
symp- dilate airways, allows more air to come in
inflammation- narrows airways-too much fluid will come in
spams of smooth muscle- narrows airways by constriction
Describe the specific details of pulmonary gas exchange (where are gases specifically going and why are they going in certain direction?)
is the diffusion of O2 from air in the alveoli of the lungs to blood in the pulmonary capillaries and the diffusion of CO2 in the opposite direction
Each gas diffuses from an area of higher partial pressure to an area of lower partial pressure
alveoli/lung- starts w/ high 02 and low co2
blood-starts w/ high co2 and low 02
swap-blood is high 02 and lung is high co2
Describe the specific details of systemic gas exchange (where are gases specifically going and why are they going in certain direction?)
The respiratory system provides the
oxygen so that the systemic circuit can
deliver the oxygen to body cells and
tissues
Each gas diffuses from an area of higher partial pressure to an area of lower partial pressure
Blood- starts w/ high 02 and low co2
tissues-starts w/ high co2 and low 02
swap-tissues is high 02 and blood is high co2
How is oxygen transported in the systemic circuit so that it can get to the cells?
oxygen will bind to the rbc because of hemoglobin
hemoglobin will use iron to help stick to cells
What is tissue perfusion?
with blood flow, oxygen delivery or a combination of flow and nutritional supply including that of oxygen.
Why is it important to maintain tissue perfusion?
vital for all metabolic processes
influences tissue repair and resistance
linked to blood flow and oxygen delivery
Describe the concept of “affinity” and how it relates to oxygen transport on red blood cells
When high partial pressure of 02, increased affinity-cell will be sticky and keep oxygen in
when low partial pressure of 02, low affinity- hemoglobin will release 02 to where it needs to go
How is CO2 transported in blood so that it can get to the lungs? How is it primarily transported and how does it get exhaled? Be able to describe the specifc transport starting at tissues and ending at alveoli–this includes the chemical reaction and chloride shift
Body cells get rid of 02, and will pick up Co2 inside of capillaries
Co2 will combine with water, will go through bicarbonate shift, and enter plasma
Bicarbonate will go from tissues to lungs, into alveoli and reverse reaction, back to c02 where lungs can now breathe it out
Chemical reaction/ chloride shift reaction
Co2 + h20 <–> H2Co3<–> Hco3 +H
cl will fill in for hco3 until it is ready to reverse reaction, then turn back into hco3
How would inflammation or excess fluid in lungs affect pulmonary gas exchange?
inflammation- decrease rate of exchange- not getting enough 02
pulmonary edema- decrease rate of exchange
What could cause fluid in the lungs (alveoli)?
- Partial pressure difference of gases
- Surface area available for gas exchange
- Diffusion distance (through respiratory
membrane) - Molecular weight and solubility of gase
What can you check for in an Arterial Blood Gas test?
partial pressure of 02
partial pressure of co2
blood ph
oxygen saturation
