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The Respiratory System. Main Structures : Mouth & Nose. Brings air into the body (Ventilation) Nasal hairs in nostrils trap dust. Main structures: Nasal cavity. Warms & moistens air Glands that produce sticky mucus line the nasal cavity
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Main Structures:Mouth & Nose • Brings air into the body (Ventilation) • Nasal hairs in nostrils trap dust
Main structures:Nasal cavity • Warms & moistens air • Glands that produce sticky mucus line the nasal cavity • traps dust, pollen, and other materials that were not trapped by nasal hairs • cilia sweep mucus and trapped material to the back of the throat where it can be swallowed
Main structures Pharynx • Tube-like passageway used by food, liquid, and air • At the lower end of the pharynx is a flap of tissue called the epiglottis • covers the trachea during swallowing so that food does not enter the lungs
Main structures Larynx • “Voice box” • The airway to which two pairs of horizontal folds of tissue, called vocal cords, are attached
Main structures Trachea • Air-conducting tube • Connects the larynx with the bronchi • Lined with mucous membranes and cilia • Contains strong cartilage rings
Main structures Bronchi • Two short tubes that branch off the lower end of the trachea • Carry air into the lungs. • Singular - bronchus
Main structuresLungs • Lungs: lie in the thorax and are separated by the mediastinum. • Right lung has 3 lobes. • Left lung has 2 lobes. • Each lung has numerous lobules. • Each lobule consists of a group of air chambers attached to a terminal bronchiole.
Main structures Bronchioles • Tiny branches of air tubes in the lungs • Connect bronchi to alveoli
Main structures Alveoli • Tiny, thin-walled, grapelike clusters at the end of each bronchiole • Surrounded by capillaries • Where carbon dioxide and oxygen exchange take place (external respiration) • Singular - alveolus
Diffusion http://www.borg.com/~lubehawk/hrespsys.htm
Functions of the respiratory system: • Gaseous exchange: oxygen from the air dissolves in the thin film in moisture on the cells lining the alveoli. • This then diffuses into the red blood cells and combines with haemoglobin to form oxyhaemoglobin
Function cont • Oxyhaemoglobin breaks down to allow the oxygen to diffuse out of the blood to be used by the cells of the body. • Blood that arrives at the alveoli from the body rich in carbon dioxide diffuses out of the blood into the air in the lungs, which can then be breathed out.
Main structures Pleura • Membrane lining the lungs and chest cavity
Main structures Diaphragm • Muscle wall between the chest and the abdomen that the body uses for breathing
Intercostal muscles • When you inhale: • the intercostal muscles contract, expanding the ribcage. • the diaphragm contracts, pulling downwards to increase the volume of the chest. • pressure inside the chest is lowered and air is sucked into the lungs. • When you exhale: • the intercostal muscles relax, the ribcage drops inwards and downwards • the diaphragm relaxes, moving back upwards, decreasing the volume of the chest. • pressure inside the chest increases and air is forced out.
Activity 1 • On your worksheets label the diagram of the respiratory system.
Activity 2 • Complete the self assessment quiz worksheets.
Learning outcomes reviewed • At the end of this session you will be able to: • List the main structures within the respiratory system. • Define respiration and gaseous exchange. • Describe two main functions of the respiratory system. • Utilise the theory provided for completion of task 2 (P3).
