Structure of the human gas-exchange system

Question 1

Mammalian lungs
Location reason

Answer 1

Located inside the body because,
-Air is not dense enough to support and protect these delicate structures
-The body as a whole would otherwise lose a great deal of water and dry out.

Question 2

Parts of Lungs and functions

Answer 2

1. Ribcage
+A bony box that protect and support the lungs
2. Lungs
+A pair of lobed structures made up of a series of highly branched tubules= Bronchioles which end in tiny air sacs=Alveoli
3. Trachea
+A flexible airway that is supported by rings of cartilage and it prevent it from collapsing from the air pressure.
+The walls are made up of muscle lined with ciliated epithelium and goblet cells.
4. Bronchi
+Two divisions of trachea.
+Similar to trachea, produce mucus to trap dirt particles and have cilia the move dirt up to the throat.
+Bronchi made up of cartilage. less with small size
5. Bronchioles
+Series of branching subdivisions of the bronchi
+Muscle lined with epithelial cells
+The muscles constrict so they can control the flow of air.
6. Alveoli
+Minute air sacs with a diameter of 100μm-300μm
+Between them, there are some collagen and elastic fibres and the alveoli are lined with epithelium.
+The E.fibres all the alveoli to stretch as they fill with air
The alveoli surface is the gas-exchange surface.