Respiration
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Respiration
من طرف srimathi الإثنين أبريل 13, 2020 8:52 am
04.13.2020
08:48:51
Biology/ grade 9- Today’s topic- The human breathing system- course book- pages144 to 146.
Main points-
The human gas exchange system
Aerobic respiration needs oxygen, and it produces carbon dioxide as a waste product. The human respiratory system contains the organs that allow us to get the oxygen we need and to remove the waste carbon dioxide we do not need. It contains these parts:
two lungs
tubes leading from the mouth and nose to the lungs
various structures in the chest that allow air to move in and out of the lungs.
Connecting the outside to the inside
Air passes from the mouth into the trachea, often called the windpipe. The trachea divides into two bronchi, with one bronchus for each lung.
Each bronchus divides further in the lungs into smaller tubes called bronchioles. At the end of each bronchiole, there is a group of tiny air sacs. These air sacs have bulges called alveoli to increase their surface area.
Ventilation
Ventilation or breathing involves movements of the ribs, intercostal muscles and diaphragm to move air into and out of the lungs:
when we breathe in, we inhale
when we breathe out, we exhale.
Gas exchange in the lungs
We need to get oxygen from the air into the blood, and we need to remove waste carbon dioxide from the blood into the air. Moving gases like this is called gas exchange.
Features of the alveoli
The alveoli are adapted to make gas exchange in lungs happen easily and efficiently. Here are some features of the alveoli that allow this:
They give the lungs a really big surface area.
They have moist, thin walls. (just one cell thick)
They have a lot of tiny blood vessels called capillaries.
The gases move by diffusion from where they have a high concentration to where they have a low concentration:
Oxygen diffuses from the air in the alveoli into the blood
carbon dioxide diffuses from the blood into the air in the alveoli.
Some water vapour is also lost from the surface of the alveoli into the lungs - we can see this condensing when we breathe out on cold days.
No homework
08:48:51
Biology/ grade 9- Today’s topic- The human breathing system- course book- pages144 to 146.
Main points-
The human gas exchange system
Aerobic respiration needs oxygen, and it produces carbon dioxide as a waste product. The human respiratory system contains the organs that allow us to get the oxygen we need and to remove the waste carbon dioxide we do not need. It contains these parts:
two lungs
tubes leading from the mouth and nose to the lungs
various structures in the chest that allow air to move in and out of the lungs.
Connecting the outside to the inside
Air passes from the mouth into the trachea, often called the windpipe. The trachea divides into two bronchi, with one bronchus for each lung.
Each bronchus divides further in the lungs into smaller tubes called bronchioles. At the end of each bronchiole, there is a group of tiny air sacs. These air sacs have bulges called alveoli to increase their surface area.
Ventilation
Ventilation or breathing involves movements of the ribs, intercostal muscles and diaphragm to move air into and out of the lungs:
when we breathe in, we inhale
when we breathe out, we exhale.
Gas exchange in the lungs
We need to get oxygen from the air into the blood, and we need to remove waste carbon dioxide from the blood into the air. Moving gases like this is called gas exchange.
Features of the alveoli
The alveoli are adapted to make gas exchange in lungs happen easily and efficiently. Here are some features of the alveoli that allow this:
They give the lungs a really big surface area.
They have moist, thin walls. (just one cell thick)
They have a lot of tiny blood vessels called capillaries.
The gases move by diffusion from where they have a high concentration to where they have a low concentration:
Oxygen diffuses from the air in the alveoli into the blood
carbon dioxide diffuses from the blood into the air in the alveoli.
Some water vapour is also lost from the surface of the alveoli into the lungs - we can see this condensing when we breathe out on cold days.
No homework
srimathi- المساهمات : 990
تاريخ التسجيل : 15/09/2018
. :: الصف التاسع GR9 :: الأحياء Biology
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