Week 1
Gastrointestinal Tracts & Nutrient Utilization |
 |
 |
Instructions for listening to audio clips
- Download the QuickTime
Player to listen to the audio files.
- Read the QuickTime
Instructions for installation help.
- Download the RealPlayer to listen to the audio files
- Instructions are on the RealPlayer download page
Anatomy and Physiology
-
Text Transcript
Time: 5.52
Follow along with the audio...
- Anatomical components
- Similarities allow basic digestive functions
- Variations allow species specific digestive functions
- Mouth and associated structures
- Functions
- Saliva
- Added during mastication
- Functions
- Aids bolus formation
- Coats bolus
- Moistens feed
- Provides enzymes
- Acts as buffer
- Esophagus
- Tube from mouth to stomach or reticulorumen
- Functions
- Transports bolus via muscular contractions
- In nonruminants: downward
- In ruminants: downward and upward
- Glandular stomach
- Functions
- Storage
- Mixing
- Initial protein digestion
- Bactericidal via hydrochloric acid (HCl)
- Cumulative activities produce chyme
- Small intestine
- Primary site for enzymatic digestion
- Three regions
- Duodenum
- Chyme neutralized by bile salts
- Bile salts
- Liver; gall bladder; duodenum
- Also, emulsify fats
- Pancreatic enzymes digest proteins, carbohydrates (CHO),
and lipids
- Additional enzymes for proteins and CHO
- Enzymatic digestion continues in the jejunum and ileum
- Absorption via villi and microvilli
- Increase surface area and absorption efficiency
- Figure 1.5 – Villi and microvilli
- Villi
- Microvilli
- Projections from each cell
- Large intestine
- Three regions
- Functions of cecum and colon
- Absorption of some organic compounds
- Absorption and resorption of water
- Primary digestion: microbial digestion
- Other functions of the GI tract
- Route for excretion of toxicants and minerals
- Synthesis of nutrients by microbes
- Examples: water-soluble vitamins, amino acids, proteins, CHO,
and lip
- Location and extent varies
- Location determines utilization efficiency
|
|
|
|
