Respiration Flashcards
(25 cards)
External respiration
Gas exchange between blood capillaries and air sacs of the lungs
Internal Respiration
Gas exchange between blood capillaries and body cells
Cellular respiration
The breakdown of organic molecules in the cell to release energy
Structures of the respiratory system
Nose and mouth
Air passages and associated structures
Lungs
Diaphragm, ribs and intercostal muscles
How is the nose supported?
By bone and cartilage, providing an entrance for air
Lining of the nose
It is lined with mucous and contains fine hairs
Purpose of hair and mucous in the nose
Hair - filters the air
Mucous - warms it
What separates the air from food?
Hard and soft palates in the mouth
What is the larynx made up of?
Cartilages
Where is the larynx located?
On the trachea
Role of the larynx
Prevents particles from entering the trachea
Houses the vocal cords
Where is the trachea located?
In the mediastinum, anterior to the oesophagus
How is the Trachea kept open?
By C-shaped cartilages, which also allow the oesophagus to expand whilst swallowing
Inner wall of the trachea
lined with mucous membrane composed of ciliated epithelium with many goblet cells
Lungs
Spongy, cone-shaped organs which occupy most of the space in the thoracic cavity
How are the lungs separated?
Medially, by the mediastinum
Enclosed by the diaphragm and thoracic cage
What is attached to the surface of the lung?
Visceral pleura
What lines the thoracic cavity?
Parietal Pleura
Alveoli walls
Thin walls of simple squamous epithelium and a rich supply of blood capillaries
The Diaphragm
Large, semi-circular sheet of muscle and tendon, attached to the base of the ribs and vertebral column
Ribs
Intercostal muscles which protect the heart and lungs, used in breathing
Inspiration
The Diaphragm contracts and moved downwards
External intercostal muscles contract to raise the ribs and sternum
Thoracic cavity increases, the lungs enlarge and air pressure in the alveoli drops
Fresh air enters the lungs
Expiration
The Diaphragm relaxes and moved back upwards
The intercostal muscles relax to allow the ribs to move downwards and inwards
Chest cavity becomes smaller and air pressure in the alveoli increases
Air is forced out of the lungs
Total lung volume
3-5 litres
