Paper 1 - Physiology Flashcards
Ventilation
Getting air into and out of the lungs
External Respiration
Gaseous exchange between the lungs and the blood
Internal respiration
Exchange of gases between the blood capillaries and the body cells
Cellular respiration
The metabolic reactions that take place in cells to create energy
Pleural cavity
Stops the lungs and diaphragm sticking together
Alveoli
Air sacs responsible for swapping gasses between the lungs and blood
Alveoli’s structure
B - Big surface area
O - One cell thick
G - Good blood supply
Diffusion
The movement of molecules from an area of high concentration/partial pressure of the molecules to an area with a lower concentration/partial pressure
Passage of air
Nearly - Nose
Lobbed - Larynx
The - Trachea
Ball - Bronchi
Brilliantly - Bronchioles
Again - Alveoli
Mechanics of breathing
Increase of volume - Thoracic cavity (chest) reduces pressure
Decrease of volume - Thoracic cavity (chest) increase pressure
Inspiration
To get air into the body
- Increasing volume
- Decreasing pressure
Expiration
To get air out
- Decreasing volume
- Increasing pressure
Inhalation at rest
- Diaphragm contracts and flattens
- Intercostals contract
- Ribs move up and out
- Volume of thoracic cavity increases
- Pressure decreases
- Air moves in
Inhalation during exercise
- Diaphragm contracts and flattens - External intercostals, sternocleidomastoid contracts
- Ribs move up and out
- Volume of thoracic cavity increases
- Pressure decreases
- Air moves in
Exhalation at rest
- Diaphragm relaxes
- Intercostals relaxes
- Ribs move down and in
- Volume of thoracic cavity decreases
- Pressure increases
- Air moves out
Exhalation during exercise
- Diaphragm relaxes
- Internal intercostals, abdominals and obliques contract
- Ribs move down and in
- Volume of Thoracic cavity decreases
- Pressure increases
- Air moves out
Lung Volumes
Movement of air into and out of the lungs, at rest we inspire and expire approximately 0.5 litres of air
Minute Ventilation Equation
Number of breaths (per min) x tidal volume = minute ventilation
Tidal Volume
Volume of air inspired or expired per breath
Inspiratory Reserve Volume (IRV)
Volume of air that can be forcibly inspired after a normal breath
Expiratory Reserve Volume (ERV)
Volume of air that can be forcibly expired after a normal breath
Residual Volume
Volume of air that remains in the lungs after maximum expiration, keeping the lungs inflated
Minute Ventilation
Volume of air breathed in or out per minute
Changes of Lung Volumes During Exercise
Tidal Volume - Increases
Inspiratory Reserve Volume - Decreases
Expiratory Reserve Volume - Slightly Decreases
Residual Volume - Remains the same
Minute Ventilation - Large increase
Anticipa
