TOPIC 2.4: DIGESTIVE SYSTEM Flashcards
(20 cards)
WHAT IS THE DIGESTIVE TRACT? HOW MUCH TIME DOES FOOD SPEND IN IT’S MAJOR COMPONENTS?
digestive tract: long muscular tube running from the mouth to the anus
mouth >1min
stomach: ~1-2 hours
small Intestine: ~7-8 hours
large intestine: ~12-14 hours
HOW MUCH OF OUR BODY WEIGHT IS REPLACED EVERYDAY? HOW OFTEN ARE CERTAIN CELLS REPLACED?
5% of body weight replaced every day
taste cells: 7 days
RBC: 120 days
skin cells: month
intestinal lining cells: 3 days
WHAT ARE THE 2 ASPECTS OF DIGESTION? LIST ELEMENTS OF THE PHYSICAL ONE
mechanical digestion
- chewing, peristalsis, segmentation, stomach action, sphicter contractions
chemical action: digestive juices
EXPLAIN THE PROCESSES OF ABSORPTION AND CIRCULATION
Absorption: nutrients arre taken in through the lymphatic and circulatory sustem
circulation moves nutrients and delivers to all cells so they can grow and regenerate
HOW LONG IS THE GI TUBE AND WHAT ARE THE END PRODUCTS OF MACRONUTRIENTS? WHAT ABOUT VITAMINS AND MINERALS?
25-30ft long
carbohydrates: monosacchardies, glucose, fructose
protein: amino acid
fat: glycerol and fatty acids
Vitamins and minerals released during digestion
EXPLAIN THE DIGESTIVE PROCESS FROM THE ORAL CAVITY TO THE STOMACH
Oral cavity +tongue: masticaiton chews up food and tongue mixes it with saliva to create bolus
- saliva contains salivary amylase and lipase which begins carb (starch) and fat digesiton. food is transferred to the esophagus where it will deliver bolus to stomach via peristalsis. stomach digests proteins via pepsin and fats float on top of mixure, stomach liquifies solids in 1hr and liquids in 1min.
WHAT ARE THE COMPONENTS OF GASTRIC JUIC AND FUNCTION OF EPITHELIAL CELLS?
gastric juice: water, HCl (denatures proteins for enzymes), enzymes
epithelial cells: produce mucus to protect stomach lining from acidity
EXPLAIN THE DIGESTIVE PROCESSES FROM THE ACCESSORY ORGANS TO THE ANUS
liver: produces bile to emulsify fat
gallbladder: stores bile and deliver to SI via bile duct
pancreas: secretes pancreatic juice containing many enzymes (pancreatic amylase, pancreatic lipase, trypsin) and bicarbonate for neutralization.
small intestine: is where bulk of absorption occurs. carbs, proteins, and fats are also digested here
large intestine: home to most intestinal bacteria and site of water absorption. carbs and some fiber digested by bactera
rectum: waste storage
anus: holds rectum closed and opens for elimination
EXPLAIN THE STRUCTURE OF INTESTINES
the intestines are around 657 square feet, absorption and digestive capabilities are enhanced by Vili
- tissue in the intestine is high mainenance, 50% SI and 80% LI nutrient needs are met by digested food
EXPLAIN THE STRUCTURE OF VILLI
- contains microvilli
- contains arteries which pick up CHO, PRO, and other breakdown products
- veins take away waste
- lymphatic system picks up fats, lympjatic fluid has substances that bind to fat and carry it to the blood strea, near the heart where systems merge into one vessel
EXPLAIN ELEMENTS OF FIBER IN THE GI TRACT
- fiber exits in the same form it enters
- humans cannot breakdown fiber (no enzyme)
- high fiber meals pass LI faster than low fiber meals
- some fiber is digested in LI via bacteria
WHAT IS THE FUNCTION OF THE LARGE INTESTINE
- home to many bacteria, absorb water, sodium and some bacterial products
- unabsorbed substances collect here to be excreted in stool
WHAT PERCENTAGES OF CARBS, PROTEINS, AND FATS ARE ABSORBED?
carbs:99%
protein: 92%
fat: 95%
WHAT IS IBS? WHAT ARE ITS SYMPTOMS AND TREATMENTS
IBS= irritable bowel syndrome
symptoms: bloating, diarrhea, constipation
treatment: probiotics+meds, low fat diet, fiber
WHAT CAUSES CONSTIPATION AND HEMORRHOIDS AND WHAT ARE SOME TREATMENT OPTIONS?
causes: low fiber diet and low physical activity
treatment: fiber intake 25-30g/day, high fluids
WHAT CAUSES ULCERS AND HEARTBURN AND WHAT ARE SOME TREATMENT OPTIONS
cause: coffee, alcohol, fatty foods, soft drinks, citrus
treatment: high fiber diet
WHAT CAUSES DIARRHEA? WHAT CAN OCCUR AFTER 2 WEEKS OF IT?
- zinc or viral contamination in water
- vitamin a, zinc, or other nutrient deficiency
- After 2 weeks, dehydration, kidney and heart malfunction can occur, or possibly death
HOW CAN YOU PREVENT DIARRHEA?
- food and water sanitizaiton, immunizations, proper diet
- rehydration fluids (pedialyte), post 4-6 hours of rehydration drink foods like yogurt, potatoes, etc provide nutrients for intestinal repair
- avoid sugary beverages
WHAT IS DIVERTICULOSIS? HOW IS IT DEVELOPED AND HOW CAN YOU TREAT IT?
Diverticulosis: intestinal wall develops buldges in weak areas –> can worsen constipaiton
caused: trapped fecal matter in pockets caused inflammation and infection
treatment high fiber diet = increase fecal mass = stimulated muscle contractions = muscles get stronger
WHAT IS FLATULENCE?
people pass gas around 14x/day (produce 1-1 1/2 L)
cause: swallowed air, breakdown of digested food via. bacteria (specifically carbs)
- heartburn, Gi disorders, and meds associated with flatulence
