Important embryological structures across vertebrate species

There are six in humans (but no fifth arch!)
The first three arches contribute to structures above the larynx while the last two contribute to the larynx and trachea

Buccinator: derived from the second pharyngeal arch and is supplied by the facial nerve but plays a role in mastication
Digastric: derived from both arches. Anterior belly supplied by trigeminal and posterior belly by facial.

	First pharyngeal arch (mandibular)	Second pharyngeal arch (hyoid)
Skeletal	Malleus	Stapes
	Incus	Temporal styloid process
	Maxilla	Stylohyoid ligament
	Mandible	Lesser cornu of hyoid
	Spine of sphenoid
	Sphenomandibular ligament
	Palatine
	Squamous temporal
Muscles	Masseter	Frontalis
	Medial and lateral pterygoids	Orbicularis oris and oculi
	Temporalis	Platysma
	Mylohyoid	Occipitofrontalis
	Anterior belly of digastric	Stylohyoid
	Tensor veli palatini and tensor tympani	Posterior belly of digastric
		Stapedius
		Auricular
		Buccinator
Nerve supply	Mandibular and maxillary branches of trigeminal	Facial
Arteries	Maxillary	Stapedial artery
	External carotid	Hyoid artery
Other	Thyroid (derived from both.C-cells are derived from the fourth laryngeal pouches)

## Third arch

## Fourth arch

## Tongue

Developed from first, third and fourth pharyngeal arches
Intrinsic muscles derived from occipital myotomes
Sulcus terminalis divides the tongue into anterior two-third and posterior one-third

Hypoglossal nerve (almost all muscles)
Vagus nerve (supplies palatoglossus)
Parasympathetic and sensory/taste fibres to the posterior third derived from the otic ganglion (from glossopharyngeal)
Taste supply to the anterior two-thirds from the chorda tympani
Sensory supply to the anterior two-thirds from the mandibular branch of the trigeminal