Lecture 3 Flashcards
What are the three types of digestive system?
- Simple system (w/o caecum)
- Simple system (w/ functional caecum
- Multiple system: Ruminant
What are the 7 parts of the GI tract?
Mouth, esophagus, stomach, small intestine, large intestine, caecum, rectum
What is solubility?
Is a carbohydrate soluble in the aqueous environment of the digestive tract?
Yes = soluble, No = insoluble
What is digestibility?
Does the host organism have the enzymes necessary to digest a carbohydrate?
Digestible CHO vs non-digestible CHO (Fibre)
What is fermentability?
Do gut bacteria have the enzymes necessary to break down a carbohydrate?
Yes = fermentable, No = non-fermentable
What are the key features of a simple system without a caecum?
Monogastric
Non-functional caecum
Considered a hindgut fermenter - fermentation occurs in the large intestine
Suited for a nutrient dense, low fibre diet
What are the features of the oral cavity?
Food is chewed, food is mixed with saliva, the two enzymes alpha-amylase and lingual lipase break down carbs and lipids
What are the features of the stomach?
The stomach empties every 2-6 hours, the pH of the stomach is 2, the food in the stomach becomes ‘chyme’, the gastric glands in the stomach secrete gastric juice, different cells in the stomach differentiate 4 different regions
What are the four regions of the monogastric stomach?
Cardia, fundus, body, antrum
What are the features of the small intestine?
Main site for nutrient digestion and absorption - nutrient gateway
Surface area is 30 m^2
Intestinal motility is controlled by longitudinal (push food forward) and circular (mix and break down food) muscles
Chyme acidity is neutralized by pancreatic juice
Food is digested by pancreatic juice/bile
What are the features of the large intestine/colon?
Site of fermentation
Production of short chain fatty acids/volatile fatty acids
Site for water absorption
What are the 3 surface areas of the small intestine?
- Kerckring folds - cells are absorbing food through the intestine
- VIlli/Crypts
- Micro villa - brush boarder
What are some features of gut bacteria?
Unique to every person
Most bacteria are anaerobic
Bacteria increases as we move along digestive system
Why are gut bacteria very important?
Fermentation of non-digestible CHO - which produces SCFA
What are the key features of a simple system with a functional caecum?
Pseudo-ruminant
Hindgut fermenter
Functional Caecum
All other regions of the gut function similar to the monogastric system
Suited for a diet with large amounts of fodder and foraging