Week 3 - Respiratory system Flashcards
Main goal of respiratory system
Gas exchange overview
Basic Anatomy
URS
LRS
Air enters through nose/mouth
warmed and moistened so not to damage LRS
Trachea branches into L and R main bronchi then becomes a tree
smooth muscle lining bronchioles regulates airflow
Alveoli
Where gas exchange occurs
Type I
Type II
Alveolar macrophages
Type I alveolar cells
97% of alveolar SA
25 nm thick permeable
Allows for transport or exchange
Type II alveolar cells
Secretes pulmonary surfactant
Create surfactant which is a lubricant for coral sack of lungs
Alveolar macrophages
Immune cell
Removes debris and pathogens
Immune cell
Phagocyte
Gross anatomy of the lungs
Left lung - 2 lobes
Right lung - 3 lobes
If one segment becomes affected with disease, it can be treated independently
Each lung sits in pleural membrane
Why does left lung have 2 lobes
Cardiac notch for heart
Inspiration and expiration
Boyle’s Law
Pulmonary ventilation (PV)
Inspiration
Boyle’s law
The higher the volume, the less the pressure
lower the volume, higher the pressure
PV
Difference in pressures drive PV
Air flows from high to low
Pulmonary ventilation and gas diffusion is moving from high to low
Inspiration
Decreasing pressure in lung
Creating gas differentiation from atmospheric pressure from around
Lower Respiratory System, Gas exchange & ventilation perfusion relationships
Respiratory volumes and capacities
Dead space
Spirogram: Normal vs. COPD
Blood flow to lungs
Respiratory volume: various volumes of air in, entering or leaving the lungs
Tidal volume
Expiratory reserve volume
Inspiratory reserve volume
Residual volume
Total lung capacity
Vital capacity
Inspiratory capacity
Functional residual capacity
Tidal Volume
TV
Normal quiet breathing
When sitting in class or reading
Expiratory reserve volume
ERV
Amount you can push out past a normal tidal volume expiration
Inspiratory reserve volume
IRV
deep inhalation - everything above normal breath
Residual volume
Amount of air left after you push out as much air as you can
If all air left, lungs would collapse
Total lung capacity
Sum of all lung volume
Vital capacity
VC
Amount one can move in or out of lungs, except RV
Inspiratory capacity
amount of air inhaled past normal tidal volume
Functional residual capacity
FRC
Amount f air that remains after normal tidal expiration
Dead space
Anatomical dead space
Alveolar dead space
total dead space
Anatomical dead space
Air left in airway that doesn’t reach alveoli
- not enough pressure to
change
Never interacts in gas exchange
Alveolar dead space
Air found in alveoli that are dysfunctional
Gas not used in exchange
Total Dead space
Anatomical dead space & alveolar dead space
All air that does not interact in gas exchange
Spirogram: Normal vs. COPD
Showing use of forced expired airflow to diagnose airway obstruction
Blood flow to lungs
Pressure in pulmonary circulation are relatively low
When person is standing, blood flow is greatest at bottom of lung due to gravity
Respiratory Rate
Total number of breaths/minute
Controlled by medulla
responds mainly to CO2
Involves both acquiring O2 and removing CO2 from blood
Normal adult breathing rate
12-18 bpm
RR controlled by brainstem
Medulla and pons
Ventilation
Movement of air into and out of lungs
Perfusion
Flow of blood in capillaries
Relationship between ventilation and perfusion
Allowing gas exchange to happen
Partial pressure
measured in pressure
In atmospheres, many different gases
Oxygen
nitrogen
CO2
External respiration
In lungs
when we inhale air, we go from high to low pressure
ppCO2 in tissue
way higher than that of blood
this allows for easy diffusion
Hemoglobin does what for transport in blood
binds oxygen
4 oxygen binding sites per Hb
if all 4 are bound, this means full saturation
Full blood oxygen saturation is
95-99%
Oxygen Dissociation from Hb
Gases travel from high to low pressure
the higher the pp of O2, the more will be bound by Hb
Lower the pp of O2, the less will be bound
Temperature affecting oxygen dissociation
High temperature allows for O2 to dissociate faster
pH affecting oxygen dissociation
more acidic pH causes more O2 dissociation
3 major mechanisms for transporting CO2 in blood
Carbaminohemoglobin
bicarbonate
blood plasma
Carbaminohemoglobin
20% of transport
CO2 binds to amino acids in Hb
Bicarbonate
70% of transport
Enzyme
Enzyme
Carbonic anhydrase
Blood plasma
CO2 dissolves in plasma
7-10% of CO2 transport
