Respiratory System Flashcards
What is cellular respiration?
The way that cells obtain their energy- usually using oxygen to break down the glucose in the cell
What is the function of the respiratory system?
Transport gases to and from the circulatory system
What is external respiration?
Exchange of gases between atmosphere and blood. O2 in co2 out
What do the lungs do?
Take O2 from atmosphere (inhale) Facilitate gas exchange of O2 for co2 Remove co2 (exhale)
What is the thorax?
Air tight chamber formed by rib cage, intercostal muscles and diaphragm
Internal surfaces lined with pleural membrane which secretes pleural fluid - lubrication
Describe the structure of the lungs?
Lungs connect the pharynx at back of mouth by trachea. Air reaches trachea by passing through larynx.- 2 bronchi- bronchioles- alveoli.
Alveoli are made of elastic tissue and a vast capillary system surrounds them.
How are the lungs adapted for gas exchange?
Large surface area
Good blood supply
Moist linings
Thin walls
How are dirt, dust and particles removed from the air we inhale?
Cilia and mucus. Mucus made by goblet cells - dirt and germs carried up to mouth and swallowed- HCL in stomach kills the germs
Describe alveolar structure and gas exchange?
700 million alveoli- total SA 70 metres squared per lung
Walls 1 cell thick and close to capillary
Blood coming to lung high in co2 and low in O2-exchange by diffusion
O2 dissolves in surface film of h2o and combines with haem to form oxyhemoglobin - co2 diffuses from blood to alveolus and exhaled.
Describe the process of inhalation?
Intercostal muscles contract- ribs move up and out Diaphragm flattens Volume of thorax increases Pressure inside thorax decreases Air drawn into lungs
Describe the process of expiration?
Intercostal muscles relax- ribs move down and in Diaphragm moves up and domed shaped Volume of thorax decreases Pressure inside thorax increases Air is expelled from lungs
How is breathing regulated?
Controlled by the medulla oblongata
Lungs have a capacity of about 6 litres
Only 0.6 lit exchanged during normal respiration- tidal volume
What is vital capacity?
During exercise, deep breathing forces out much more of the total lung capacity - up to 4.5 lit of air can be inhaled or exhaled
What is residual volume?
Vital capacity is always 1- 1.5 lit less than the total capacity because of air trapped in the trachea and bronchi = residual volume
What are the diseases of the respiratory system?
Asthma- allergy causing constriction of airway
Bronchitis- inflammatory reducing airflow causes smoking, irritants
Cystic fibrosis- genetic defect- excessive mucus produced clogs airways
COPD
