Unit 3 Flashcards
What is peristalsis?
Rhythmic muscle contractions of the intestines during digestion
What can effect transit time of digestion?
Diet, physical activity, emotion, medications, illness
What are enzymes?
protein molecules that speed up the breakdown of nutrients. Different enzymes are needed to break down different nutrients.
Describe regulation of GI Function
Digestive hormones are produced by cells lining the GI and accessory organs. They help prepare different parts of the GI for the arrival of food and help regulate digestion of nutrients and the rate that food moves through the GI
What is digestion ?
Is the process of breaking food into components small enough to be absorbed by the body
What is absorption?
Is the process of taking substances into the interior of the body where they are transported through the bloodstream or lymph
What are heartburn and GERD caused by?
The leakage of stomach contents into the esophagus
What are gallstones?
small, hard, pebble-like deposits made primarily of cholesterol, bile, and calcium. They can cause pain and interfere with fat digestion.
What is Total Parenteral Nutrition?
requires nourishing a patient by providing all needed nutrients directly into the circulatory system (via IV) when the gut is not able to digest and/or absorb nutrients.
What is enternal or tube feeding?
is a liquid diet provided directly to the stomach or intestine through a tube placed down the throat or through the wall of the GI.
What role does the mouth play in digestion and absorption?
The entry point of food is the mouth where mechanical and some chemical breakdown occurs. Saliva, released by the salivary glands, combines with masticated food to create a bolus. Salivary amylase is secreted by the salivary glands along with saliva and begins the chemical breakdown of carbohydrates in the mouth.
What role does the pharynx and esophagus play in digestion and absorption?
From the mouth, food passes through the pharynx and into the esophagus. Peristalsis propels the bolus down the esophagus to the stomach.
What role does the stomach play in digestion and absorption?
Acts as a temporary storage unit for food. The muscles of the stomach mix the bolus with stomach secretion into a semi-liquid mass called chyme, and gastric juice containing hydrochloric acid and pepsin begins protein digestion.
What role does the small intestine play in digestion and absorption?
Is the primary site for nutrient absorption. Bicarbonate neutralizes stomach acid, and pancreatic and intestinal enzymes digest carbohydrate, fat, and protein. The digestion of fat in the small intestine is aided by bile from the gallbladder. Secretions from the pancreas and liver are regulated by the hormones secretin and cholecystokinin (CCK), produced by the duodenum. The absorptive surface area of the small intestine is increased by folds, finger-like projections called villi, and tiny projections called microvilli, which cover the surface of the villi.
What role does the large intestine play in digestion and absorption?
Does not participate in digestion. It can absorb some water and some negligible vitamins and minerals. Slow movement through the large intestine favours growth of “good” bacteria (intestinal microflora) which acts on some unabsorbed materials, such as fibre, producing small amounts of nutrients that can be absorbed (fatty acids) and gas. The remaining unabsorbed materials are excreted in feces.
