The aortic bodies are peripheral chemoreceptors sited around the inferior surface of the aortic arch. They are small masses of glomus tissue around 3-4mm in diameter - smaller than the carotid bodies. They have a very high rate of metabolism which is mirrored by a high blood transit rate through them.

There are two types of cell within the aortic bodies:

• type I cell: main sensory cells for stimulation by hypoxia, acidaemia
• type II cell: glial supporting cells

The aortic bodies are supplied by fibres of the vagus nerve:

• efferent: modulate sensitivity to hypoxia by regulating blood flow through the bodies
• afferent: signal extent of chemical changes within the blood