Changes

==Structure==

==Structure==

*The trachea contains numerous rings of hyaline cartilage which are C-shaped, being dorsally incomplete, connected to eachother by elastic connective tissue. The ends of the incomplete rings are joined by smooth muscle - ''Trachealis'' muscle.

*The trachea contains numerous rings of [[Bones and Cartilage - Anatomy & Physiology#Hyaline Cartilage|hyaline cartilage]] which are C-shaped, being dorsally incomplete, connected to eachother by elastic connective tissue. The ends of the incomplete rings are joined by smooth muscle - ''Trachealis'' muscle.

**The structural conformation of the trachea prevents collapse due to traction forces, whilst allowing it to adjust in length and diameter as the neck moves and the diaphragm contracts.  

**The structural conformation of the trachea prevents collapse due to traction forces, whilst allowing it to adjust in length and diameter as the neck moves and the [[Diaphragm - Anatomy & Physiology|diaphragm]] contracts.  

*The trachea's walls are made up of a number of layers: Inner Mucosa, Fibrocartilaginous middle layer, and and adventitia (in the neck) or serosa (in the thorax).

*The trachea's walls are made up of a number of layers: Inner Mucosa, Fibrocartilaginous middle layer, and and adventitia (in the neck) or serosa (in the thorax).

*The inner mucosa contains glands which produce mucus. This mucus traps debris and is constantly moved upwards towards the pharynx where it is swallowed. This mechanism is known as the ''Muco-Ciliary escalator''.

*The inner mucosa contains glands which produce mucus. This mucus traps debris and is constantly moved upwards towards the [[Oropharynx - Anatomy & Physiology|oropharynx]] where it is swallowed. This mechanism is known as the [[Respiratory Epithelium - Anatomy & Physiology#Mucociliary Escalator|''Muco-Ciliary escalator'']].

==Function==

==Function==