BIOL 3070 Lecture Notes - Lecture 19: Salivary Gland, Digastric Muscle, Gastrointestinal Tract
Document Summary
Alimentary canal is continuous with the external medium as the mouth and anus form an opening and. Headgut: receives ingested material through the mouth, composed of: mouth, oral cavity, pharynx, teeth, tongue and salivary glands, tongue: assists in mechanical digestion and swallowing and taste through chemoreceptors, salivary gland: secretes amylase to digest partially. Salivary glands: secretes saliva that is made up of 99. 5% water and 0. 5% electrolytes and proteins: -amylase, lingual lipase (that is activated in the stomach at ph=4), mucus, Antimacrobial (lysozyme, lactoferrin and alctoperoxidase: process of formation of saliva: 1) acinar cells: active transport of sodium and chlorine and water will follow. 2) duct cells: salivary fluid moves down in the duct and undergoes modification by active reabsorption of nacl and adding potassium and bicarbonate. In mammals and vertebrates: swallowing is an all or none reflex. 1) oropharyngeal stage: moving food from the mouth to the pharynx and to the esophagus.
