Structure of the Respiratory System Flashcards
The Respiratory System (29 cards)
How does air enter the body?
Through the mouth and nose
Describe the lining of the nose/nasal cavity
The lining of the nose and nasal cavity is complex and lined by mucous membranes.
Describe the passage of air through the nose
As the air passes over the membranes, it is warmed and humidified.
There are also hairs and mucus lining the nose.
These trap debris, preventing it from reaching the lungs.
What is the pharynx?
The pharynx, or throat, is the region from the nasal cavity to the top of the trachea and oesophagus.
Describe the passage of air through the pharynx
Air travels through it before being diverted into the trachea by the epiglottis, a flap of elastic cartilage.
What is the role of the epiglottis?
During inhalation the epiglottis covers the oesophagus, guiding the air into the trachea; when swallowing, the epiglottis covers the larynx, preventing food from entering it.
What is the larynx?
The larynx is a cartilage structure joining the pharynx and trachea.
Describe the structure of the larynx
Contains the vocal cords, which are mucous membranes that are able to vibrate as air passes over them. This is why the larynx is also known as the voice box.
What is the trachea?
The trachea is also known as the windpipe because it carries the air into and out of the lungs
Describe the structure of the trachea
It is made up of C-shaped cartilage rings that hold the structure open.
At its base, the trachea splits into two branches, one branch taking air into each lung.
What does the c-shaped cartilage allow the trachea to do?
This ensures that air can always pass through it.
What is the role of mucus in the trachea?
The epithelial lining of the trachea produces mucus, which is able to trap dust and debris. This prevents it from entering the lungs.
What is the role of cilia in the trachea?
The cilia that also line the trachea are able to move in a wave-like motion to take the mucus and debris up to the pharynx so that it can be swallowed and digested.
What are the bronchi?
At the end of the trachea, the structure splits into two primary bronchi, one for each lung.
These then split further into secondary bronchi which take the air into each lobe of the lung.
The secondary bronchi continue to divide, forming tertiary bronchi.
Describe the structure of the bronchi
The structure of the bronchi is very similar to the trachea, with C-shaped cartilage rings.
What happens as the bronchi get smaller?
As the bronchi get smaller, the cartilage is more spread out, with smooth muscle and elastin forming more of the structure.
What is the role of cilia and mucus in the trachea?
As in the trachea, cilia and mucus work together to trap and remove dust and other particles from the airways.
What are bronchioles?
When the tertiary bronchi divide, they form smaller airways called bronchioles, which continue to split until they end in millions of terminal bronchioles
Describe the structure of the bronchioles
Unlike bronchi, bronchioles do not contain cartilage; instead, they are made of smooth muscle and elastin.
Relate the structure of the bronchioles to its function
This allows the bronchioles to control the flow of air in the lungs, expanding when the body needs more oxygen.
What is the role of cilia and mucus into the bronchioles?
Cilia and mucus are also present in the bronchioles, protecting the lungs from contaminants.
What are the lungs?
The two lungs take up the whole of the chest cavity, except for the space between them, called the mediastinum, that is occupied by the heart and blood vessels.
Describe the structure of the lungs
Each lung is divided into lobes. The left lung has two lobes; the right lung has three
What is pleura?
A membrane that covers the surface of the lungs (the visceral pleura) and also lines the inside of the chest (the parietal pleura).
