chapter 3- digestion, absorption and transportation

what are some challenges of digestion?

• multiple tasks of the mouth

• passage through the diaphragm

• steady movement

• lubrication of food

• digestive enzyme functions

• excretion of waste

what is the order of organs in the digestive system?

mouth, esophagus, stomach, small intestine, large intestine, rectum, anus

what is the lumen?

the inner spaced of the intestines

what is bolus?

a mass of chewed food

what is the role of the mouth in digestion?

• process begins

• taste sensations = sweet, sour, bitter, salty, umami/savory

• passes through pharynx

what is the role of the esophagus/stomach in digestion?

• upper/lower sphincter = control movement

• chyme (semi-liquid mass)

intestines

• small intestines = 3 segments

• large intestines/colon = withdrawal of water

what is segmentation?

contraction of circular muscles in the small intestine

what are the (5) organs involved in the secretion of digestion?

• salivary glands

• stomach

• pancreas

• liver

• small intestine

what are the functions of saliva and gastric juice?

• saliva = moistens foods

• gastric juice = protein digestion

anatomy of the absorption

• villi

• microvilli

• crypts

• goblet cells

• specialized cells

• food combining

what is the function of the lymphatic system?

• one-way

• entry into bloodstream

• nutrients in lymphatic vessels

what are the influences of the gastrointestinal microbiome?

• prebiotics and probiotics

• environmental factors

how are gastrointestinal hormones and nerve pathways connected?

• homeostasis

• endo-nervous systems

• feedback mechanisms

what are examples of common digestive problems?

• choking

• vomiting

• constipation

what are the causes of ulcers?

• bacterial infection

• anti-inflammatory drugs

• excessive gastric acid secretion