Pancreas

Pancreas Anatomy Located retroperitoneal, posterior to stomach Midportion from the upper right to the left quadrant Parts Head Body Tail

Pancreas Complex organ Two types of function Exocrine function Endocrine function

Function of Pancreas Exocrine function Compound acinar gland – connects to small ducts – connects to larger ducts – joins the pancreatic duct – joins the common bile duct and enters the duodenum (small bowel)

Function of Pancreas What are the secretions and what do they do? Hco3 Enzymes to digest protein Trypsin Chymotrypsin Carboxypeptidases Nuclease Enzyme to digest Carbohydrate Pancreatic amylase Enzymes to digest Lipids Pancreatic lipase

Function of Pancreas Control of function Form Initiating factor Result Hormonal Secretin Acidic chyme Large amounts of HCO3 to neutralize acid Cholecystokinin Fatty acids and amino acids Digest fatty acid and amino acids Neural Parasympathetic stimulus food Secretion of enzymes into the gut

Function of Pancreas Endocrine function Specialised cells (tissue) – secretes hormones directly into blood stream

Digestion Digestion – breaking down of food to molecules Mechanical – larger to smaller Chemical – breaking of covalent bonds

Digestion, Absorption and Transport

Digestion Digestion – breaking down of food to molecules Carbohydrates – monosaccharides Protein – aminoacids Fats – fatty acids and glycerol

Absorption Absorption – begins in the stomach Mainly alcohol,asprin but NOT the three main food products

Transport Transport – move the molecules across the intestinal wall Facillitated diffusion- no need energy e.g glcose from cell to blood Cotransport – requires energy e.g glucose from intestine to cell Active transport – requires energy e.g amino acid from blood to organs

Carbohydrate, Lipid Protein , Water and Mineral

Carbohydrate Cellulose Starches Glycogen Sucrose Fructose Lactose (plant cell- fiber not carbohydrate) Starches (plant energy storage molecule) Glycogen ( muscle energy storage molecule) Sucrose Fructose Lactose Complex carbohydrate Disacharide

Carbohydrate Digestion Complex carbohydrate Polysaccharides Salivary amylase Complex carbohydrate Polysaccharides Pancreatic amylase Disacharides Polysaccharides Disacharidase-intestine Disacharide Monosaccharides

Carbohydrate Monosacharide Disaccharide Digestion Glucose + Glucose Glucose + Maltose Glucose + Galactose Sucrose Fructose Lactose Disaccharidase Monosacharide Disaccharide

Carbohydrate Absorption and Transport Glucose is the end product in blood is a source of energy is stored and use by the cells and increased/decreased by the presence of insulin Intestine Intestine cell Blood/capillary Cotransport Facillitated diffusion

Lipids Triglycerides Phospholipids Steroids – three fatty acids and glycerol Phospholipids – required for transport and solubility of fat Steroids Cholesterol, corticosteroid, esters

Lipids Digestion Transforms large lipid into smaller droplets Lipid Emulsification by bile salts Transforms large lipid into smaller droplets Lipid Pancreatic amylase Transforms large lipid into smaller droplets Fatty acid and monoacylglycerides

Lipids Absorption and Transport Carried in lacteals as chyle into liver and stored as cholesterol, LDL, HDL Within Intestine cell they are packed into chylomicron Intestine Simple diffusion Exocytosis LDL,HDL, Triglyceride and cholesterol is the end product in blood is a source of energy is stored and use by the cells

Proteins Plant protein Animal protein

Proteins Digestion Protein Polypeptides Polypeptides Peptides Pepsin Protein Polypeptides Trypsin,chymotrypsin,carboxypeptidase Polypeptides Peptides Peptidases Amino acids Peptides

Protein Absorption and Transport Carried in blood to liver and throughout the body Within Intestine cell they brokendown to amino acid Intestine Cotransport Active transport Amino acid is the end product in blood is a source of building block and the rest is metabolised to release energy and indirectly converted to small amounts of glycogen and the rest as fat which is stored and use by the cells. Transport is stimulated by growth hormone and insulin

Water and Mineral 9 liters enters the digestive tract 2l – food 1l – salivary gland 2L – Gastric secretion 1.2L – Pancreatic secretion 0.7L – Bile 2L – Small intestine 97% absorbed in small intestine 6-7% in large intestine 1% excreted in faeces

Water and Mineral Absorption and Transport Na ,K, Ca, Mg, PO4, Cl- Intestine Within Intestine Blood Osmosis Osmosis Na ,K, Ca, Mg, PO4, Cl- Blood Active transport Passive transport in duodenum /Active transport in ileum