Job of assistant 1: Pancreas Endocrine (“Endo-” = within) function: secretes insulin & glucagon Help keep blood glucose level within normal limits Exocrine (“Exo-” = from outside) function: pancreatic cells produce pancreatic juice Juice contains: 1) Sodium bicarbonate: neutralizes acid chime from stomach 2) Digestive enzymes: amylase digesting starch, trypsin digesting protein, lipase digesting fat

Regular Blood Glucose Levels High Glucose Levels (Hyperglycemia) Pancreas releases INSULIN → Storage of glucose as glycogen in Liver & Muscles Regular Blood Glucose Levels (Homeostasis) Pancreas releases GLUCAGON→ Release of glucose from breaking down glycogen in Liver & Muscles Low Glucose Levels (Hypoglycemia)

Pancreas in detail

Diabetes mellitus Most body cells are unable to take up glucose as they should Diabetics’ glucose levels remain elevated for several hours Cells have no glucose although there are plenty of glucose molecules in the blood

Type 1 Diabetes (insulin-dependent) Pancreas does not produce insulin Cause: a virus which causes cytotoxic T cells to destroy pancreatic islets Fat is used as main source of energy, which leads to a build up of ketones (acidic) in the blood Injection of insulin required, but with overdose of insulin or missing a meal, hypoglycemia can result Symptoms of hypoglycemia: perspiration, pale skin, shallow breathing, anxiety Pancreas transplants possible

Type 2 Diabetes (insulin-resistant) Obesity can lead to type 2 because adipose tissue produces a substance that impairs insulin receptor function Blood insulin level = low Cells do not have enough insulin receptors Prevention by diet/life-style changes possible If left untreated, effects can be as serious as type 1

Long-term complications of both types Blindness Kidney disease Cardiovascular disorders Atherosclerosis Heart disease Stroke Reduced circulation

What do these organs look like in real life? Look at the microscopic slides of: Pancreatic islet cells Draw what you see Label parts using the internet/textbook Relate structure to function

Job of assistant 2: Liver (“hepatic”) Largest gland in the body Upper right section of abdominal cavity, under diaphragm Approximately 100, 000 lobules Triads in between lobules: Bile duct = takes bile away from the liver Hepatic artery = brings oxygen rich blood to liver Hepatic portal vein = transports nutrients from intestines

Job of assistant 2: Liver (“hepatic”) Removes poisonous substances from the blood coming through the hepatic portal vein Bile production and excretion Metabolism of fats (glycerol → glucose), proteins (amino acids→ glucose), and carbohydrates (maintains blood glucose level at about 0.1 %) Enzyme activation Storage of glycogen, vitamins (A, D, E, K and B12), iron and minerals Synthesis of plasma proteins (helps regulate cholesterol level), such as albumin, and clotting factors

What is Bile? Dark green to yellowish brown liquid Stored in the Gallbladder Bile acids, salts, phospholipids, cholesterol, pigments, water, electrolyte chemicals Emulsifies fats: sound familiar?

What do these organs look like in real life? Look at the microscopic slides of: Hepatic lobule Draw what you see Label parts using the internet/textbook Relate structure to function

Failure of assistant 2: Liver Hepatitis Inflammation of the liver A: usually from sewage-contaminated drinking water B: usually spread by sexual contact, blood transfusions or contaminated needles C: usually spread by contact with infected blood Can result in “Jaundice” = yellowish tint to whites of eyes or skin due to bilirubin deposited in the skin Can result in chronic hepatitis, liver cancer

Failure of assistant 2: Liver 2. Cirrhosis Organs become fatty → Liver tissue replaced by inactive fibrous scar tissue Often in alcoholics: malnutrition and excessive amounts of alcohol Liver transplantation preferred treatment for liver failure Liver can regenerate itself just from 25% of its original mass

Job of assistant 3: Gallbladder Pear-shaped, muscular sac attached to surface of the liver About 1 L or bile produced by liver each day, therefore any excess bile is stored in the gallbladder Water reabsorbed from bile Bile becomes thick, mucus-like Cholesterol in bile can come out of solution → Form crystals → Crystals grow in size → Gall-stones → Gallbladder passage (common bile duct) blocked → Obstructive jaundice