1. Lecture 2b- 17 January 2019
Lecture based largely on chapter 1 of
Advanced Nutrition and Human Metabolism
by Gropper et al -5th edition-on 2 hour reserve in library
plus
Chapter 7 of Understanding Normal and Clinical
Nutrition-10th edition

2. Lecture 2ab- 15,17 January 2019
Main components of this lecture are:
    a) overview of metabolism
    b) the cell and how it works in metabolism
    c) digestion and how it contributes to
metabolism

3. Outline of lecture 2ab
a) Overview of Metabolism
        -definition
        -catabolism
        -anabolism
        -metabolic regulation
                    - why is regulation necessary?

4. Metabolism cannot take place without the cell
       
b) The cell
    -required as a location to house some metabolism
and to produce components for metabolism no
matter where such metabolism occurs
    -specific aspects of metabolism occur at specific points in the cell
    -must know where metabolism occurs to
understand what is happening and why

5. The cell   
- cell components
                -plasma membrane
                -cytoplasmic matrix
                -mitochondrion
                -nucleus
                -endoplasmic reticulum
                -golgi apparatus
                -lysosomes and peroxisomes

6. The cell  
     -cellular proteins
                -receptors and intracellular signalling
                -transport proteins
                -catalytic proteins

7. The cell -apoptosis -programmed cell death
-cellular enzymes that take the cell offline- implications for disease

8. c) digestion and how it contributes to metabolism
         -cells are essential for digestion
        -overview of the structure of the digestive tract
        -structures of upper gastrointestinal tract
        -structures of lower gastrointestinal tract and accessory organs

9. -coordination and regulation of digestive processes
                -regulatory peptides
                -neural regulation

10. MORE DETAILED COMMENTS
-the process of digestion-secretions and enzymes required for nutrient digestion
                -oral cavity
                -esophagus
                -stomach
                -small intestine
                -colon or large intestine

11. c) Digestion and how it contributes to metabolism
                -cells are essential for digestion- impossible to have and regulate digestion and therefore all other metabolic processes without cells note the use of cells-plural-why?

12. Overview of the structure of the digestive tract
        -structures of upper gastrointestinal tract
                        -oral cavity- mouth and pharynx
                        -esophagus
                        -stomach

13. Overview of the structure of the digestive tract
-structures of lower gastrointestinal (gi) tract and accessory organs
                    lower gi tract
                        -small intestine
                        -large intestine
                    accessory organs
                        -liver
                        -pancreas
                        -gall bladder

14. Coordination and regulation of digestive processes
  -regulatory peptides
         -gastrin-stimulates release of HCl
         -cholecystokinin
-stimulates release of pancreatic juices and enzymes
-stimulates bile release from gall bladder
        
               

15. Coordination and regulation of digestive processes
  -regulatory peptides
        
        -secretin-stimulates release of pancreatic
juices
-inhibits gut motility-why is this important in conjunction with stimulation of release of pancreatic juices
               

16. Coordination and regulation of digestive processes
 -regulatory peptides
         -gastric inhibitory polypeptide
-inhibits gastric secretions and motility
         -somatostatin
-inhibits release of gastrin, gastric inhibitory peptide, secretin and
vasoactive intestinal peptide
                                       

17. Coordination and regulation of digestive processes
  -regulatory peptides
          -motilin
-causes contraction of smooth muscle in
intestinal wall
          -vasoactive intestinal peptide
-stimulates intestinal secretions
-relaxes most gi sphincters
-inhibits gastric acid secretion
-stimulates pancreatic bicarbonate secretion into the small intestine
                         

18. Coordination and regulation of digestive processes  
   -regulatory peptides
              -gastrin releasing peptide
-stimulates release of HCl, gastrin and CCK
              -neurotensin
-may mediate gastric emptying, intestinal motility and gastric acid secretion after fat ingestion
              

19. Coordination and regulation of digestive processes
   
  -regulatory peptides
              
              -substance P-increases blood flow to gi
tract, inhibits acid secretion,
inhibits small intestine motility

20. Coordination and regulation of digestive processes
-neural regulation
               enteric nervous system-nervous system of gastrointestinal tract

21. Coordination and regulation of digestive processes
-neural regulation
             
What is a plexus?
                       -myenteric plexus
controls peristaltic activity and/or
gastrointestinal motility
                       -submucosal plexus
controls mainly gastrointestinal
secretions and local blood flow

22. Coordination and regulation of digestive processes
-neural and hormonal regulation
             
why have both?

23. The process of digestion-secretions and enzymes required for nutrient digestion
                -oral cavity
                        -teeth-function in digestion
                        -saliva
                               -alpha amylase
-starch
                                -linguinal lipase
-triglycerides
                                -mucins
-lubricate food

24. The process of digestion-secretions and enzymes required for nutrient digestion
-esophagus
                    -peristalsis
                    -lower esophageal sphincter
-regulates entry of food into stomach
why have sphincters at all?

25. The process of digestion-secretions and enzymes required for nutrient digestion
      
          -stomach
                    -parietal cells
secrete HCl and intrinsic factor
-intrinsic factor essential to absorption of vitamin B12
                    -chief cells
secrete precursors of pepsin used to
degrade protein
                  

26. The process of digestion-secretions and enzymes required for nutrient digestion
      
          -stomach
                    -endocrine cells
secrete hormones related to digestion eg gastrin
                    -pyloric valve
-controls dumping in duodenum

27. The process of digestion-secretions and enzymes required for nutrient digestion
-small intestine
           -involvement of liver, gall bladder and pancreas                      
                            -lipases
                            -proteases
                            -carbohydrases
           -absorption which ultimately leads to transport within the body- significance for metabolism?
          -ileocecal valve-controls dumping into colon

28. The process of digestion-secretions and enzymes required for nutrient digestion
-colon or large intestine
             -water retention-why not let the kidney worry solely about this?
             -bacterial digestion of certain nutrients undigested prior to colon
-primarily dealing with carbohydrate
and to some extent proteins and amino acids
             

29. The process of digestion-secretions and enzymes required for nutrient digestion
-colon or large intestine
             -short chain fatty acid absorption
2-4 carbon fatty acids produced by bacterial fermentation of carbohydrate
used for energy in the body

30. The process of digestion-secretions and enzymes required for nutrient digestion
-colon or large intestine
             -vitamin K(some bacterial production) and biotin absorption
             -sodium, chloride and potassium absorption- again why not let the kidney worry solely about ion retention?
              

31. Next 2 lectures
metabolism of
carbohydrates not including fibre