The Oral Cavity allows the introduction of food to the Digestive System. It is the first step and allows for both mechanical and chemical breakdown. Several features are involved and will be discussed.
The Esophagus is the second step to digestion and closely follows the oral cavity – once swallowing has initiated.
The Cephalic phase begins in the mouth and starts even prior to the introduction of food. Taste and smells stimulate release gastric secretion and saliva is secreted. Salivary amylase begins the process of digestion. Starches are broken down here.
– Marks the transition from skin to the mucous membrane
– Helps in the mechanical breakdown of food in the digestive system
3 Primary Glands:
– These are Exocrine glands
– They release saliva and mucous
– They help with the breakdown of starch and maltose
– Salivary amylase found in saliva
– It is a large and powerful muscle – classified as a skeletal muscle.
– Help manipulate food for swallowing
– It has a primary function to help with taste
– Are papillae and come in 3 out of 4 forms
1.) Filiform (thread-shape)
2.) Fungiform (mushroom-shape)
3.) Circumvallate (ringed-circle)
4.) Foliate (leaf-shape)
– Filiform are the only form that has no taste buds
Other Important Factors:
1.) Motor innervation – Hypoglossal nerve – (Cranial nerve XII)
2.) Some smaller muscle innervations – Vagus nerve – (Cranial nerve X)
3.) Sensory innervations – Trigeminal nerve, Facial nerve, and Glossopharyngeal nerve