NUTR 207 Study Guide - Final Guide: Pylorus, Esophagus, Sphincter

• School: McGill University
• Department: Nutrition and Dietetics
• Course: NUTR 207
• Professor: Linda Wykes

Document Summary

Need to break down food and absorb (cells take up nutrients and transport to body) Food is crushed (chewed) in mouth, lubricated with saliva (contain enzymes to break down carbs, enables tasting, easier to swallow) Goes down esophagus (food tube), trachea protected by epiglottis. Esophagus has upper and lower sphincter (muscle ring) to control entrance/exit of food. Bolus retained in upper part of stomach, slowly mixed with juice and goes to lower part, slowly released through pyloric sphincter. Gallbladder and pancreas add secretions through bile duct. Nutrients absorbed in small intestine (duodenum, jejunum, ileum). Colon absorb water, bacteria digest some fibre and remaining nutrients. Rectum/anal canal hold back waste until expelled through anus (2 sphincters) Peristalsis: consecutive contractions down the gi tract by the rings of muscle (rings tighten, longitudinal loosens). Speed varies depending on location and presence of food (ex: stomach speed up when food is inside). Stomach: thickest walls, has extra layer of diagonal muscles (churning action)