Assignment 4 – Respiratory System
, The Respiratory System diagram
Epiglottis/
Nasal
Pharynx
cavity
Larynx
Trachea
Lungs
Bronchioles
Bronchus
Alveoli
Diaphragm
Nasal cavity – This starts in the nose, and leads to the epiglottis. It is lined with hair to filter
the air, removing debris, and to moisten the air.
Epiglottis/Pharynx - The epiglottis is a flexible flap at the start of the larynx. It acts as a
switch between the larynx and the oesophagus. It protects you from choking on food that could
obstruct the airway.
Larynx - The larynx is a tough, flexible part of the respiratory tract connecting the pharynx to
the trachea in the neck. It plays a vital role in the respiratory tract by allowing air to pass
through it while keeping food and drink from blocking the airway. The larynx is also the body’s
“voice box” as it contains the vocal folds that produce the sounds of speech and singing.
Trachea - The trachea, also called the windpipe, filters the air that is inhaled. It branches into
the bronchi, which are two tubes that carry air into each lung.
Bronchus – This is where the air enters the lungs. It is the biggest passageway, and it send air
into the left and right lung. They branch off into the bronchioles, smaller tubes.
Bronchioles – These are small tubes that split off from the bronchus. There are lots of them to
make the respiration process more efficient. It means that more air will get sent to the alveoli.
Alveoli – These are located at the end of the bronchioles. They are tiny air sacs that allow the
exchange of gases. Surrounding the alveoli, there is a dense network of capillaries to allow to
exchange. Capillaries are one cell thick, and the alveoli are thin walled to allow the diffusion of
gases. There are loads of bronchioles and alveoli so that the air can be spread out, to lower
blood pressure, so they don’t burst or break.
Diaphragm – This is located underneath the lungs. It is a respiratory muscle, the main muscle
involved in breathing at rest. It is dome-shaped, which determines the space in the thoracic
cavity. It contracts and moves down during inspiration, and relaxes and moves up during
expiration.