6.6,6.7,6.8: Human gas exchange, breathing and lungs Flashcards
Mammalian lungs
Site of gas exchange in mammals
Why are the lungs located inside the body
- air isn’t dense enough to support and protect them
- body as a whole would lose a lot of water and dry out
Ribcage
bony box that supports and protects the lungs
Lungs
Pair of lobed structures made up of bronchioles which end in alveoli.
Trachea
Flexible airway that is supported by rings of cartilage
Role of rings of cartilage in trachea
prevents trachea from collapsing as the air pressure falls inside when breathing
Bronchi
Two divisions of the trachea, each leading to one lung. each produce mucus to trap dirt particles and cilia.
Bronchioles
Series of branching sub-divisions of the bronchi with walls made of muscle which allows them to contract and is lined with epithelial cells. Control air flow in and out of alveoli.
Alveoli
Minute air sacs at the end of the bronchioles.
Alveolar membrane function
gas exchange surface
What is between the alveoli
collagen and elastic fibres
Role of elastic fibres between alveoli
Allow them to stretch as they fill with air when breathing in
Ventilation
Air is constantly moved in and out of the lungs.
aka breathing
Diaphragm
Sheet of muscle that separates the thorax from the abdomen
Intercoastal muscles
Lie in between the ribs
2 sets
