Respiratory System Revision

Respiratory System The respiratory system is mainly concerned with breathing The function of the respiratory system is to get oxygen into the body and carbon dioxide out of the body. The parts of the respiratory system are: air passages lungs diaphragm

Respiratory system

Respiratory System

Passage of Air Enters the nasal cavity, here the air warms, moistens & is filtered. Air then passes into the larynx Air is then passed down the trachea (windpipe) Air then moves through the bronchi (left & right bronchus) Air then passes into the bronchioles Air then goes into the alveoli

Gaseous Exchange

Gaseous exchange The O² breathed in goes through the mouth or nose, down the trachea, into the lungs and into the alveoli. The O² passes through the alveoli walls into the red blood cells, via the capillaries. The O² joins with haemoglobin to make oxyhaemoglobin. The oxyhaemoglobin is used by the working body and is transported by the circulatory system to cells needing to release energy. CO² is produced as a waste product This is converted into a gas and passes back through the alveoli walls, via the capillaries into the blood plasma. Blood takes it back to the capillaries in the lungs. CO² passes through the capillary and alveoli walls into the alveoli. It is then exhaled from the body.

Mechanism of Breathing Inspiration Diaphragm pulls down Intercostal muscles contract Air pressure is reduced Air is sucked through the tubes into the lungs Chest expands Expiration Diaphragm relaxes into its dome position Intercostal muscles relax Chest becomes smaller Pressure increases on lungs Air is forced out

Composition of Air Inhaled 79% = Nitrogen 20% = Oxygen Exhaled Trace = Carbon Dioxide Exhaled 79% = Nitrogen 16% = Oxygen 4% = Carbon dioxide

Definitions Vital Capacity The maximum amount of air that can be forcibly exhaled, after breathing in as much as possible. Residual Volume The amount of air left in the lungs after a maximal breath. Respiratory Rate Number of breaths per minute Tidal Volume Amount of air breathed in or out at rest Minute Volume Volume of air breathed in, in 1 minute.

Respiratory System during exercise Tidal volume increases Breathing rate increases and becomes deeper and more regular Heart beat increases, supplying the demand for more O² in the working muscles Gaseous exchange in alveoli increases

Long-term effects of training on the respiratory system Endurance Increased training makes gaseous exchange in the alveoli more efficient. Muscles are able to work at a harder level for longer without tiring – increasing the vital capacity of the lungs. Interval over short distances at high speeds New capillaries are formed, heart muscle is strengthened and delivery of O² improves.