Topic 9: Gas Exchange Flashcards
Name all the structures of the gas exchange system
Trachea, lungs, bronchus, bronchiole, alveoli, diaphragm, ribs, intercostal muscle
Name all features in the trachea
Smooth muscle, lumen, C-ring of cartilage, ciliated epithelium, connective tissue (elastic fibres, collagen), goblet cells, cilia, mucus glands
What do bronchi and the trachea have that the bronchioles don’t?
Goblet cells, submucosa, cartilage
What type of epithelial cells do bronchioles have?
Ciliated cuboidal epithelium cells
What type of epithelial cells do bronchi and the trachea have?
Ciliated epithelium cells
What type of epithelial cells do alveoli have?
Squamous epithelium cells
What is the purpose of cartilage?
Support, to stop the trachea and bronicholes from collapsing
How is cartilage fit for purpose?
- made of collagen and elastic fibres, providing mechanical strength, and stretch and recoil
- stretches and recoils during ventilation
What is the purpose of cilia?
To sweep mucus up out of the lungs to remove microorganisms and dust to keep lungs clean
What is the purpose of goblet cells?
Secrete mucus to keep lungs clean
What is the purpose of mucus glands ?
To produce mucus secreted by goblet cells
What is the purpose of smooth muscle?
To contract and relax to change diameter during ventilation
What is the purpose of elastic fibres?
To provide elasticity by stretching and recoiling during ventilation
What are adaptations of alveoli for efficient gas exchange?
- liquid surfactant for oxygen to dissolve in
- large surface area
- thin walls (one layer of squamous epithelium)
- elastic fibres for stretch and recoil
- surrounded by blood capillaries
- short diffusion distance
What is the process of gas exchange?
- air is cleaned and warmed
- alveoli expand
- oxygen dissolves in surfactant
- oxygen diffuses into blood stream and enters red blood cell
- carbon dioxide diffuses out of blood stream
- elastic fibres recoil and air leaves the lungs
