VAN 221: Veterinary Splanchnology and Applied Anatomy (1+1)

TRACHEA
(Sheep, Goat, Horse, Pig, Dog, Rabbit, Fowl)

Species Difference

Sheep and Goat

• The average length of the trachea is about nine or ten inches and its caliber is little less than an inch
• In the sheep, the ends of the tracheal cartilages overlap in the cranial third of the trachea and in the caudal third, the left ends of the tracheal cartilages extend further dorsally than the right ends
• The trachea of the goat is U shaped on cross section with variable distance between the right and left ends of the cartilages

Horse

• It is longest; about 75 to 80 cm. Caliber is 5 to 6 cm
• The free ends of the rings overlap in the cervical part while they do not meet in the dorsal part
• It does not give any additional bronchus to the right lung and is not adherent to the lungs

Pig

• Consists of 32-35 rings, which overlap dorsally
• Occasionally, adjacent cartilages become partly or completely fused
• A special apical bronchus is detached for the apical lobe of the right lung

Dog

• It contains about 40 to 45 rings, which are C-shaped, and their ends do not meet dorsally
• Trachealis muscle is attached to the outside of the cartilages

Rabbit

• The trachea is about 6cm long and possesses no apical bronchus

Fowl

• The cartilage rings are complete
• The trachea connects the cranial larynx and syrinx or caudal larynx