CH 4 Digestion and absorption Flashcards
(26 cards)
What are the organs of the digestive/gastrointestinal (GI) tract?
Mouth, Esophagus, Stomach, Small Intestine, Large Intestine, Rectum, Anus
What is the difference between digestion and absorption?
Digestion breaks down food into smaller pieces. Absorption transfers nutrients from D.I tract to bloodstream
How are the contents of the GI tract propelled along its length?
Through peristalsis a wavelike contraction of smooth muscle
How do enzymes aid digestion?
they speed up chemical reactions, including the breakdown of food into absorbable nutrients
What substances are found in saliva?
water, mucus, lysozyme, amylase, lingual lipase
What are the 5 basic taste sensations?
Sour, salty, sweet, umami, bitter
How does the swallowing process prevent food from entering the trachea?
The epiglottis closes over the larynx/ trachea
What are the 6 components of gastric juice?
hydrochloric acid, pepsinogen, mucus, intrinsic factor, gastric lipase, electrolytes
How do HCl and the enzyme pepsin aid in digestion?
HCI activates pepsinogen and created pepsin that breaks down proteins into peptides
Describe the locations and functions of the 5 sphincters along the GI tract.
Upper Esophageal (UES): Prevents air from entering the esophagus.
Lower Esophageal (LES): Prevents acid reflux into the esophagus.
Pyloric Sphincter: Regulates stomach emptying into the small intestine.
Ileocecal Valve: Prevents backflow from large to small intestine.
Anal Sphincters: Controls defecation
Where is bile synthesized and what is its function?
synthesized in the liver and helps breakdown fats, aids in absorption of fat, eliminates waste
What is the role of the pancreas in digestion?
exocrine gland, producing enzymes and bicarbonate to aid in breaking down food
What is the role of the liver in digestion?
produces substances essential for digestion and nutrient processing
Describe key digestion regulatory hormones.
Gastrin: Stimulates Stomach Acid Secretion
Secretin: Stimulates Bicarbonate Secretion & Inhibits Acid
Cholecystokinin (CCK): Stimulates Digestive Enzyme & Bile Release
Gastric Inhibitory Peptide (GIP): Slows Gastric Activity & Promotes Insulin Release
Motilin: Stimulates Gut Motility
Where does the majority of absorption happen?
Small intestine (jejunum and ileum)
Explain the three main types of absorption that we discussed. Which type of absorption requires energy?
Passive Diffusion (Simple Diffusion): more nutrients than lumen. (energy not required)
Facilitated Diffusion: uses carrier proteins to help transport nutrients (energy not required)
Active Transport: needs carrier proteins and ATP (requires energy)
What are the nutrients that are transported by the cardiovascular system?
Water soluble nutrients such as carbohydrates, proteins, certain vitamins, minerals, water
What are the nutrients that are transported first in the lymphatic system?
fat soluble nutrients such as lipids and vitamins ADEK
Which organ first receives nutrients from the cardiovascular system?
The liver
What are the main functions of the large intestine?
Water and electrolyte absorption, processing waste, immune defense, waste elimination
What are some of the beneficial actions of the bacteria in the large intestine?
Digest fiber, makes vitamins, protect against harmful bacteria, aid in waste breakdown
What is the difference between a pre and a probiotic? Where can they be found in the diet?
Probiotics: Live beneficial bacteria that help gut health (Yogurt, kefir, kimchi, sauerkraut, miso, kombucha)
Prebiotics = Food for probiotics, fibers that help good bacteria grow ( Bananas, onions, garlic, asparagus, oats, apples)
What is the most common cause of peptic ulcers?
Helicobacter pylori (H. pylori) bacteria
What are nutritional factors that can increase the risk of gallstones? Who is at a higher risk?
High fat, low fiber, high sugar, low calories (women, obese people, people over 40, diabetics)
