Biomechanics - Respiration Flashcards
What is necessary for respiration to occur?
O2 must be obtained form environment and CO2 removed from body back into it
What is the cellular respiration equation?
C6H12O6 + 6O2 –> 6CO2 + 6H2O + ATP
What kind of sources can O2 be extracted from?
water or air
How much air is in water and the atmosphere?
Air = 21% Water = 3-5%
How does respiration occur in worms?
O2 and CO2 diffuse directly between the blood vessels just underneath their skin
For terrestrial animals such as humans, what main organ do we have that allows us to exchange gases?
Lungs
What structure does O2 and CO2 go through to get into our lungs?
Airways
What are the three phases of gas exchange in an animal which has lungs?
1 - Breathing
2 - Transport of gases by circulatory system
3 - Diffusion of gases from blood to cells
What is the order of air flow during inhalation through the different structures of the lungs?
Larynx, trachea, bronchi, bronchioles then alveoli
What is a key feature of alveoli that allows for efficient gas exchange?
High SA:V ratio (FYI there are ~500million alveoli which have a radius of ~125μm and is only one cell thick)
What is the technical term for breathing?
Ventilation
What does ventilation refer to?
The moment of air into and out of the lungs
What is the process of air entering our lungs called? Why does this occur?
- Inhalation
- alveolar pressure decreases below atmospheric pressure
What is the pressure of air leaving our lungs called? Why does this occur?
- Exhalation
- alveolar pressure increases above atmospheric pressure
What is the physical mechanism of ventilation?
- Inhalation: rib cages expand (as rib muscles contract) and diaphragm contracts (moves down)
- Exhalation: rib cage gets smaller (rib muscles relax) and diaphragm relaxes (moves up)
What does a pressure volume charge for the lungs describe?
The change in pressure in the lungs as there is a change in volume
How is the work done by the lungs calculated?
The area between the curves
How does a pressure volume chart differ between one for the lungs and heart?
For lung PV chart the pressure is on the x-axis and volume and y-axis, for heart it is the other way around (e.g. volume on y-axis and pressure on x-axis)
What is the slope of the PV lung diagram called?
Compliance
What is compliance?
A measure of show much the lung volume changes for a given change in pressure
What is the equation for compliance?
∆V/∆P
How does compliance change as volume increases?
Compliance decrease as lung volume increases
What are the three factors that work is required to overcome while breathing?
1 - over come surface tension
2 - expand elastic lung tissue
3 - overcome air resistance as it flows through airways