Key Nutrients in Digestion and Metabolism Flashcards
Discuss the process of digestion ?
Digestion breaks down food into its basic nutrients so that these nutrients can be absorbed and transported to the cells.
Once absorbed, these nutrients can be used to fuel our cells for growth, fight infection and provide energy to our muscles and our brain to perform daily activities.
What is the gastrointestinal tract?
A long hollow tube containing several layers that begins with the mouth and ends at the anus.
What are the three processes that the body can use to absorb nutrients from the GI tract into the blood or lymph system and eventually into the cells?
- Passive Diffusion - substances move easily in and out of cells with out the use of energy.
- Facilitated Diffusion - special protein carriers are needed to help substances cross into or out of the cell. No energy is required.
- Active Transport - energy is needed to get the substance into or out of the cell.
What kind of stimuli initiatates the digestive system before any food even enters the mouth?
- Cognition - thoughts about food can start the flow of saliva.
- Sound - hearing a description of the meal.
- Odor - the smell of food stimulates your hunger response and aids in the taste of food.
- Appearance - seeing the food.
- Taste - or mouth feel begins as the food enters your mouth.
What are the five flavors that can be tasted?
Sweet, sour, salty, bitter and umami (a meaty flavor)
What is the role of the salivary glands?
They secrete saliva into the mouth which contains mucus, enzymes and other substances.
Salivary amylase breaks down starch and lingual lipase begins to act on fats. During this process, mucus is being mixed with the food particles to lubricate, and make it easy to swallow a mouthful of food.
What is the esophageal sphincter?
This is a circular muscle that constricts (closes) once food moves through to the stomach to prevent backflow of stomach contents into the esophagus.
In the stomach the food particles are mixed with _____________
gastric juice and enzymes… The acid in the gastric juice prepares proteins for digestion and activates enzymes
Pepsin is an enzyme that breaks down proteins
Gastric lipase is an enzyme that begins fat digestion
What hormone controls the overall process of the release of acidsa and enzymes in the stomach?
Gastrin plays a major role in controlling the concentration of acid in the stomach
What is intrinsic factor?
a substance produced in the stomach that is absolutely needed for the absorption for Vitamin B-12
Where does most of the digestion and absorption of food occur in the GI tract?
The small intestine, which is approx 10 feet long
What is the shortest and longest section of the small intestine?
The shortest is the duodenum and the longest is the ileum
Where do the fat soluble nutrients go in the small intestine?
The fat soluble nutrients go into the lymph system, while the other nutrients are absorbed into the blood stream.
The liver produces _____________ which is stored in the __________ and enters the ____________ through the common bile duct. The bile begins to break down ____ into smaller pieces that can be mixed with water.
bile; gallbladder; duodenum; fat
Discuss the role of the pancreas….
The pancreas is an accessory digestive organ that releases pancreatic juice and hormones. The pancreatic juice is a mix of water, bicarbonate and enzymes that break down carbohydrates, protein and fats. The bicarbonate neutralizes the acidity of the chime to protect the intestinal wall. Without the bicarbonate, the high level of acid would destroy the lining leading to an ulcer. The hormones glucagon and insulin are also released to help with glucose regulation.