Class two Flashcards
Henrys Law
Gases diffuse (move) from high pressure areas to low pressure areas.
Often called a pressure gradient
Pressure gradient is a force (p) that acts in a direction from higher toward lower pressure.
How does oxygen get into the blood stream?
Inhale
Pressure of oxygen in alveoli is greater than pressure, the pressure of the oxygen in the blood entering pulmonary capillaries
Oxygen leaves the alveoli and enters the blood stream to be circulated and supply tissues with oxygen
How carbon dioxide leaves the blood stream?
Pressure of carbon dioxide in blood stream is greater than the pressure of carbon dioxide in the alveoli
So, carbon dioxide enters the alveoli, and we exhale
Effect of smoking on lungs:
Smoking introduces particulate carbon (from pollution and tobacco) into the lungs
● Macrophages in the lungs engulf these particles but they cannot be broken down leading to black spots in the lung tissue.
● Loss of elasticity and lung volume which usually enables them to inflate efficiently
Gases exchange:
refers to the movement of oxygen into the blood and carbon dioxide out of the blood.
Components of the Pleural linkage
Pleura
Visceral pleura
Parietal pleura
Interpleural space
Pleura
single celled membrane
small amount of fluid produced by pleura Creates smooth surface for lungs to expand and get smaller within the ribcage
Visceral pleura
encloses lungs
Parietal pleura
lines inside of chest wall (rib cage)
Interpleural space
- Between the parietal and visceral pleura ,contains a small amount of fluid which helps lungs move smoothly within the chest during breathing
Negative pressure
Pleural membranes constantly absorb the fluid and gases that exist in the space between them.
This constant absorption causes negative pressure
Because of the negative pressure, visceral and parietal pleura are sucked together
Maybe referred to as “pleural cavity pressure” – always negative
Pleural linkage
Forces both lungs and ribcage away from their normal rest positions .. Definition: The connection between the lungs and the chest wall, maintained by negative pressure in the pleural space.
● Function: This linkage forces the lungs to expand and the ribcage to contract, allowing for breathing.
Lungs-Thorax Unit
Lungs are naturally in a collapsed state – will recoil to 1/3 of their size when thorax is opened
Thorax is naturally expanded
Resting Expiratory level
The point in the respiratory system where the opposing forces of the lungs and thorax are in balance
Balance point to which we always return after a quiet exhalation
moving above or below this determines how much and what type of muscle effort is required
This is because of the Pleural linkage.
Muscle activity is needed to breathe in but not out.
Pleurisy
Inflammation of visceral and parietal pleura
inflammation of the pleura
The condition can make breathing extremely painful.
Sometimes it is associated with another condition called pleural effusion, where excess fluid fills the area between the membrane’s layers.
