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Science For Forth Primary - Term Two - Human respiratory system
The Respiratory system:
* The respiratory system is the system which works to supply the body with (Oxygen) and to take away (carbon dioxide) and (water vapour).
* It is found in the chest (thorax) cavity.
The respiration process:
It is the process in where the air "rich in oxygen" enters the two lungs and the air "rich in carbon dioxide" released outside the two lugs.
Note:
The more active your body is, the more your respiration times increases.
Digested food:
The main parts of the respiratory system:
1- The Nose:
It contains nostril opening that oxygen enters the body through
The nose contains:
A- Hair:
To obstruct and filter dust and microbes before the entering of air to the lungs.
B- Mucus:
To moisten air.
C- Blood:
- Capillaries (Tiny blood vessels)
- To warm air
2- The Pharynx:
- It is the common cavity for digestive system and respiratory system.
- It allows air to pass from the nose to the larynx.
3- The Larynx:
It is a duct connecting between pharynx and trachea, it is called voice organ.
The larynx contains:
A- Epiglottis:
To close the (trachea) during (swallowing) to prevent food from entering the respiratory system.
B- Two vocal cords:
They produce sound when they vibrate.
4- The trachea & two bronchus (wind pipe):
* Their walls contain "cartilage rings" to be opened all time for berating breathing.
* They have "mucosal membrane with cilia" to sweep out any strange bodies.
* The bottom of the trachea "branches into two narrow tubes is called bronchi" enter the lungs.
5- The two lungs:
* The two lungs occupy the (thoracic cavity) and they are interiorly surrounded by (the ribs).
* They are on both sides of the heart.
* They contain millions of tiny (air sacs) called (alveoli), these alveoli are surrounded by networks of (blood capillaries) in which gas exchange takes place.
* The walls of (alveoli) and of the (blood capillaries) are (thin) to permit the gas exchange.
* (Diaphragm) separates the (thoracic) cavity from the (abdominal).
Mechanism of Respiration:
Exhalation: is the process of getting air rich in carbon dioxide out of the lungs.
Inhalation: is the process of entering air rich in oxygen into the lungs.
Exchange of gases:
(Exchange) of gases occurs between the air existed (in alveoli) and (the blood) flows in the capillaries via (through) their (thin walls) where blood leaves (carbon dioxide) and carries the (oxygen) and distributes it all over the body cells
The Respiratory system:
* The respiratory system is the system which works to supply the body with (Oxygen) and to take away (carbon dioxide) and (water vapour).
* It is found in the chest (thorax) cavity.
The respiration process:
It is the process in where the air "rich in oxygen" enters the two lungs and the air "rich in carbon dioxide" released outside the two lugs.
Note:
The more active your body is, the more your respiration times increases.
Digested food:
The main parts of the respiratory system:
1- The Nose:
It contains nostril opening that oxygen enters the body through
The nose contains:
A- Hair:
To obstruct and filter dust and microbes before the entering of air to the lungs.
B- Mucus:
To moisten air.
C- Blood:
- Capillaries (Tiny blood vessels)
- To warm air
2- The Pharynx:
- It is the common cavity for digestive system and respiratory system.
- It allows air to pass from the nose to the larynx.
3- The Larynx:
It is a duct connecting between pharynx and trachea, it is called voice organ.
The larynx contains:
A- Epiglottis:
To close the (trachea) during (swallowing) to prevent food from entering the respiratory system.
B- Two vocal cords:
They produce sound when they vibrate.
4- The trachea & two bronchus (wind pipe):
* Their walls contain "cartilage rings" to be opened all time for berating breathing.
* They have "mucosal membrane with cilia" to sweep out any strange bodies.
* The bottom of the trachea "branches into two narrow tubes is called bronchi" enter the lungs.
5- The two lungs:
* The two lungs occupy the (thoracic cavity) and they are interiorly surrounded by (the ribs).
* They are on both sides of the heart.
* They contain millions of tiny (air sacs) called (alveoli), these alveoli are surrounded by networks of (blood capillaries) in which gas exchange takes place.
* The walls of (alveoli) and of the (blood capillaries) are (thin) to permit the gas exchange.
* (Diaphragm) separates the (thoracic) cavity from the (abdominal).
Mechanism of Respiration:
Exhalation: is the process of getting air rich in carbon dioxide out of the lungs.
Inhalation: is the process of entering air rich in oxygen into the lungs.
Exchange of gases:
(Exchange) of gases occurs between the air existed (in alveoli) and (the blood) flows in the capillaries via (through) their (thin walls) where blood leaves (carbon dioxide) and carries the (oxygen) and distributes it all over the body cells
