Breathing and Oxygen Flashcards
What is breathing rate? (f)
Number of inspirations and expirations per minute
What is tidal volume?
Volume of air inspired or expired per breath
What is minute ventilation? (VE)
Volume of air inspired or expired per minute (product of f and TV)
What is the correct order for pulmonary ventilation?
- MMVPA
- Muscle
- Movement
- Volume
- Pressure
- Air movement
What type of breathing is passive?
Expiration at rest
What changes happen to inspiration during exercise?
- More dramatic, stronger contractions
- More muscles recruited
What are the additional inspiratory muscles?
- Sternocleidomastoid
- Pectoralis minor
What changes happen to expiration during exercise?
- Becomes an active process
- Additional expiratory muscles recruited
What are the additional expiratory muscles?
- Internal intercostals
- Rectus abdominis
What centre is ventilation controlled by?
RCC (respiratory control centre)
What are the normal inspiratory muscles?
- External intercostals
- Diaphragm
What is the process of respiratory control?
- Receptor Feedback
- RCC
- Action
What are the elements of the RCC?
- Inspiratory centre
- Expiratory centre (inactive at rest)
What nerves and muscles are active in ventilation at rest?
- Intercostal nerve stimulates external intercostals
- Phrenic nerve stimulates the diaphragm
What receptors are used by the Inspiratory CC?
- Chemoreceptors (CO2 in air)
- Proprioceptors (movement at lungs)
- Thermoreceptors (higher temperature)
What receptors are used by the Expiratory CC?
- Baroreceptors (detect tissue stretch)
What changes occur at the muscles during exercise?
- PO2 decreases
- PCO2 increases
What does the change in gas pressure at muscles during exercise cause?
Steeper diffusion gradient means more diffusion takes place
What is the role of haemoglobin and myoglobin?
Oxygen binding proteins. Myoglobin is in the blood and has a higher affinity
What is the saturation of blood leaving the lungs?
Always 100%
What changes in terms of saturation during exercise?
At rest, only around 25% of oxygen is dissociated at the muscles, increasing to 75% during exercise
What impacts on haemoglobin’s O2 affinity?
- Partial pressure of O2 (High means affinity)
- Partial pressure CO2 (Low means affinity)
- Acidity (Acidic means low affinity)
- Temperature (High temp means low affinity)
What is the Bohr Shift?
A right shift in the oxygen dissociation curve due to acidity, CO2, temperature, O2 levels at muscles. More oxygen is dossociated at intense levels of exercise
