Anatomy and Physiology of Digestive System Syahruramdhani, MSN, M.Sc School of Nursing Medical Faculty and Health Sciences Universitas Muhammadiyah Yogyakarta Objectives • Name and locate the organs • Describe the general appearence of the organs • Describe the function of the organs Digestive System • The digestive system is the organ system that processes food, extracts nutrients from it, and eliminates the residue. • The digestive system has two anatomical subdivisions, the digestive tract and the accessory organs. Digestive System • The digestive tract also known as the alimentary canal. It includes the mouth, pharynx, esophagus, stomach, small intestine, and large intestine. • The accessory organs are the teeth, tongue, salivary glands, liver, gallbladder, and pancreas. Digestive System 1. Ingestion 2. Secretion 3. Mixing and propulsion (Motility) 4. Digestion (Mechanical and Chemical) 5. Absorption and 6. Defecation Mouth (Teeth and Tongue) • The mouth, also referred to as the oral or buccal cavity. • The cheeks and lips play important roles in procuring food and keeping it in the mouth. • The palate is a wall or septum that separates the oral cavity from the nasal cavity, and forms the roof of the mouth. Mouth (Teeth and Tongue) • The teeth are collectively called the dentition. • They serve to masticatethe food, breaking it into smaller pieces. • This not only makes the food easier to swallow, but also exposes more surface area to the action of digestive enzymes and thus speeds up chemical digestion. Mouth (Teeth and Tongue) • The tongue although muscular and bulky, is an agile and sensitive organ with several functions: • it aids in food intake; • it has sensory receptors for taste, texture, and temperature that are important in the acceptance or rejection of food; • it compresses and breaks up food; it maneuvers food between the teeth for mastication; Mouth (Teeth and Tongue) • it secretes mucus and enzymes; • it compresses the chewed food into a soft mass, or bolus ,that is easier to swallow; • it initiates swallowing; and • it is necessary for articulate speech. Salivary Gland • Saliva moistens the mouth, digests a small amount of starch and fat, cleanses the teeth, inhibits bacterial growth, and moistens food and binds particles together to aid in swallowing. • It is a solution of 97.0% to 99.5% water Salivary Gland • salivary amylase,an enzyme that begins starch digestion in the mouth; • lingual lipase,an enzyme that is activated by stomach acid and digests fat after the food is swallowed; • mucus, which binds and lubricates the food mass and aids in Swallowing; Salivary Gland • lysozyme, an enzyme that kills bacteria; • immunoglobulin A (IgA),an antibody that inhibits bacterial growth; and • electrolytes, including sodium, potassium, chloride, phosphate, and bicarbonate salts. Salivary Gland • There are two kinds of salivary glands, intrinsic and extrinsic. • The intrinsic salivary include lingual glands in the tongue, labial glands on the inside of the lips, and buccal glands on the inside of the cheeks. • The extrinsic salivary include parotid, sublingual and submandibula glands. Salivary Gland Pharynx and Esophagus Stomach • Stomach is organ with “J” shaped that connect esophagus and small intestine. • Base on anatomy, histology and function divide into 3 parts, they are: 1. Fundus 2. Body 3. Antrum Stomach References • Tortora, G. J., & Derrickson, B. H. (2008). Principles of anatomy and physiology. John Wiley & Sons. • Guyton AC, Hall JE (2006). Textbook of Medical Physiology, 11th ed. Chapter 5, Pages: 307-326. • Saladin K (2003). Anatomy and Physiology: The Unity of Form and Function, 3rd ed. Chapter 23, Pages: 879-913. • Scanlon VC, Sanders T (2007). Essential of Anatomy and Physiology, 5th. Chapter: 18, Pages: 417- 438. .