Pulmonary structure And Function Flashcards
What are the main functions of the respiratory system?
Provide a means of gas exchange between the external environment and the body
Maintaining blood gas homeostasis during exercise
Define pulmonary ventilation
Movement of air in and out of the lungs to provide environment for gas exchange
Define ventilation
The volume of air breathed in and out per min (tidal volume x breathing frequency)
Define tidal volume
Amount of air breathing and out per breath
Define chemoreceptors
Nerve cells which monitor the blood and detect a raise in carbon dioxide levels and decrease in pH levels
Describe lung structure
As air is breathed in through the nasal cavity to pharynx to larynx to tranches to bronchi to bronchioles
The lungs provide the gas exchange surface that separates blood from the surrounding alveolar gaseous environment.
Oxygen transfers from alveolar air to alveolar capillary blood
Describe the alveoli
The lungs contain alveoli
Alveoli are elastic, moist and permeable and surrounded by a network of capillaries
Gas exchange happens in the alveoli
Oxygen diffused from the alveolus to the blood from a high to a low partial pressure
Define ventilation breakpoint
The point during intense exercise at which ventilation increases disproportionally to the oxygen consumption
Excess ventilation comes directly from carbon dioxide release from th buffering of lactic acid
What is Henry’s law of gases?
Gases dissolve in liquids in proportion to their partial pressures, depending on their solubility in the specific fluids and depending on temperature
Describe the mechanics of inspiration at rest
Lower the air pressure in the lungs by increasing the volume
digraph muscles contract and flatten
Intercostal muscles between the ribs contract and lift the ribcage up and out
Decrease in air pressure allows air to be drawn in as it travels from a high pressure outside to a low pressure inside the lungs
Describe the mechanics of expiration at rest
External intercostal muscles and the diaphragm relaxes
Volume of the thoracic cavity decreases
Air pressure increases
Air forced out
Describe the mechanics of breathing during exercise
The chemoreceptors detect an increase in carbon dioxide levels and therefore a change in the ph levels. The receptors sends a message to the medulla. The medulla sends a message down the phrenic nerve to the respiratory control centre
The respiratory control centre sends a message to the muscles to increase the rate and depth of breathing
