2.1 Structure and function of the ventilatory system Flashcards
What are the three main functions of the conducting airways?
- Low resistance pathway for airflow
- Defence against chemicals and other harmful substances that are inhaled
- Warming and moistening the air
Outline the function of low resistance
Nasal passages are a low resistance pathway for airflow. Allows ventilation to occur easily. Important for supplying the body with oxygen.
Outline the function of defence
The nose and throat contain tiny hairs, called cilia. They filter the air and trap particles that are present. This stops them from entering the lungs and causing infections.
Outline the function of warming and moistening the air
Air needs to be warmed to aid with thermoregulation of the body - cold air in the lungs could cause capillaries to vasoconstrict (get smaller). Environment of the lungs needs to remain moist to allow for gas exchange to take place. The nose and trachea moisten the air that is inspired.
Define pulmonary ventilation
Inflow and outflow of air between the atmosphere and the lungs (also called breathing)
Define total lung capacity (TLC)
Volume of air in the lungs after a maximum inhalation
Define vital capacity (VC)
Maximum volume of air that can be exhaled after a maximum inhalation
Define tidal volume
Volume of air breathing in and out in any one breath during normal breathing
Define expiratory reserve volume
Volume of air in excess of tidal volume that can be exhaled forcibly
Define inspiratory reserve volume
Additional inspired air over and above tidal volume
Define residual volume
Volume of air still contained in the lungs after a maximal exhalation
Draw the pulmonary ventilation diagram
Explain the mechanics of ventilation regarding inspiration
External intercostal muscles contract which makes the ribs move up and out. This lowers the pressure relative to the outside pressure. The volume increases. This all makes air move into the lungs. Air moves from high to low pressure. Diaphragm contracts which increases volume.
Explain the mechanics of ventilation regarding expiration
Internal intercostal muscles relax which makes the ribs fall. This decreases the volume in the lungs which increases the air pressure relative to the air outside. This all makes air move out of the lungs. Air moves high to low pressure. Diaphragm relaxes which decreases the volume.
What is haemoglobin?
Main protein in the red blood cells that transports oxygen around the body
Where are red blood cells produced?
Erythrocytes (red blood cells) are found i the red bon marrow (spongey bone) of long bones
Which hormone regulates the production of haemoglobin?
Erythropoetin (EPO)