Mouth cavity:

1. Floor of foregut (Endoderm)
2. Stomodeum (Ectoderm)

In between is the Buccopharyngeal membrane which ruptures at the end of the 3rd week

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Salivary glands

1. Parotid gland: Ectodermal

• Ectodermal groove appears behind the angle of the mouth
• Closes to form the parotid duct
• Branches repeatedly and canalizes to form acini
• Duct recedes from the angle of the mouth
• Duct opens in vestibule, opposite maxillary 2nd molar

2. Submandibular gland: Endodermal

• Endodermal groove appears between tongue and gums
• Closes to form submandibular duct
• Branches repeatedly and canalizes to form acini
• Anterior end of duct proceeds forwards , and opens close to frenulum of tongue

3. Sublingual gland: Endodermal

• Arise as small buds from submandibular groove
• Attain common sheath
• Has several openings in floor of mouth

Clinicals:

1. Cyst formation – Lymphoepithelial cysts/branchial cysts commonly found in the anterior triangle of the neck
2. Agenesis (failure to develop) of gland
3. Atresia (no canalization) of duct