Digestion: The pancreas, gallbladder and digestive enzymes Flashcards
Pancreas:
Exocrine functions; Enzymes
The pancreas is an accessory digestive organ that has both exocrine and endocrine functions.
* The key exocrine function of the pancreas is to produce enzymes that digest carbohydrates, proteins and fats. These enzymes are secreted into the small intestine
* Pancreatic enzymes are imperative for digestions and are part of ‘pancreatic juice’ (1.2 – 1.5 L / day)
* Pancreatic enzymes include:
o Pancreatic amylase: carbohydrate-digesting
o Pancreatic lipase: fat-digesting
o Proteases (trypsin, chymotrypsin): protein-digesting
Endocrine = secreted directly into the blood, exocrine = secreted into duct/s
Pancreas:
Anatomy and main function
The pancreas is about 6 inches long and sits in the posterior abdomen, behind the stomach
* It is connected to the duodenum by the pancreatic duct, which is used to secrete pancreatic juice into the duodenum
* If pancreatic enzyme production is poor, foods ferment in the intestines, resulting in symptoms such as bloating, flatulence and abdominal pain about one hour after eating. The lack of digestion can also lead to weight loss
Digestive enzymes:
Summary; Saliva
- Location: Saliva
- Enzyme: Salivary amylase
- Digesting: Carbohydrates (Starches) Into smaller-chained carbohydrates
Digestive enzymes:
Summary; Stomach
- Location: Stomach
- Enzyme: Gastric lipase
- Digesting: Fats into fatty acids
- Enzyme: Pepsinogen = pepsin
- Digesting: proteins into smaller peptide chains
Digestive enzymes:
Summary; Pancreas
- Location: Pancreas
- Enzyme: Pancreatic amylase
- Digesting: Carbohydrates (starches) Into even smaller-chain carbohydrates such as maltose
- Enzyme: pancreatic lipase
- Digesting: Fats into fatty acids
- Enzyme: pancreatic proteases
- Digesting: proteins into smaller peptides chains
Digestive enzymes:
Summary; Small intestine brush border (Microvilli)
- Small intestine brush border (Microvilli)
- Enzyme: Sucrase
- Digesting: Sucrose into glucose + Fructose
- Enzyme: Maltase
- Digesting: Maltose into glucose + glucose
- Enzyme: Lactase
- Digesting: Lactase into glucose + galactose
- Enzyme: Dipeptidase
- Digesting: Dipeptides into single amino acids
Over-eating
When eating often and too much, digestive enzymes are used up. Not all food can then be digested, resulting in malnutrition and bodily dysfunctions.
* Eating junk food leads to the cravings of nutrients. The body is hungry. Adding more junk food worsens the situation
* By over-eating, organ such as the pancreas and stomach are placed under stress. They are constantly under demand to produce digestive juices, potentially depleting their capacity. Furthermore, Energy is directed away from healing/repair, increasing the risk of disease.
Over-eating:
Energy expenditure
Individuals eating a well-balanced nutritious diet use about 10% of their daily energy expenditure digesting and absorbing food. This can increase to 50% in those who eat dense forms of protein (meat, soya) and junk food
Therefore, overeating and the excessive ingestion of animal proteins compromises other body functions leading to fatigue, reduced immunity and so on
Over-eating:
Tips
To support digestive system health:
* Do not eat more than three meals a day
* Avoid over-eating and snacking between meals
* Don’t drink with meals
Over-eating:
Bernard Jensen
- Bernard Jensen found that undigested materials are stored in the mucus– secreting lining of the intestines, impairing the absorption and delivery of nutrients to body tissues. The thicker the lining of undigested materials, the worse the absorption of nutrients
- This would create an optimal environment for parasites and candida to flourish, as well as under nourishing body tissues and organs
- Supporting the body’s detoxification is key to aid the body’s elimination of these wastes. Intermittent fasting and dietary changes to minimize the digestive system load also important
- Jensen also recommended vegetable broths
Gallbladder:
Bile
The gallbladder is a pair-shaped sac that sits under the liver.
* The gallbladder stores and releases bile that is produced by the liver. Bile consists mostly of water, as well as bile salts (conjugated the amino acids glycine and taurine in the liver), cholesterol and bilirubin
* Bile ducts collect bile produced by hepatocytes, before pooling in the gallbladder. Bile enters the small intestine via the common bile duct
* Predominantly after ingesting fat, the gallbladder contracts and ejects bile down the common bile duct into the duodenum
Hepato – liver, cyte = cell
Gallbladder:
Functions
The gallbladder have the following functions:
* Fat emulsification: Bile breaks lipids into smaller molecules. This increases the surface area for pancreatic lipase
* Carries detoxified products from the liver: after the liver has detoxified harmful materials, it excretes them into bile, which provides a medium for excreting these substances
* Stimulates peristalsis: bile stimulates intestinal peristalsis (and hence the removal of waste via the bowels)
* Excretes excess cholesterol: bile contains excess cholesterol that the body wishes to excrete
Poor bile flow does affect fat digestion and the body’s ability to eliminate toxins via the bowel
Emulsify = to disperse
Biliary tree
Bile is carried from the hepatic ducts into the gallbladder by the ‘cystic duct’. Here, bile is stored.
* Upon stimulation (i.e. by CCK), the gallbladder contracts and ejects bile
* The Pancreatic duct (carries pancreatic enzymes) meets the common bile duct and carries both bile and pancreatic juice through the sphincter of Oddi into the duodenum
* The adequate production and release of bile and pancreatic juice is dependent upon sufficient water consumption
* Bitters also stimulate the release of pancreatic juice and bile via the biliary tree, supporting digestion
