Nutrition in Humans

• The various organs in the alimentary canal enable efficient digestion, absorption, and assimilation of food
• The small intestine is convoluted and contains many villi to increase surface-area-to-volume-ratio for better absorption
• The digestive system consists of the alimentary canal and associated organs that work collectively to break down large, insoluble molecules of food into smaller soluble molecules
• Enzymes in digestion:

  • Functions of enzymes (e.g. amylase, maltase, protease, lipase) in digestion, listing the substrates and end-products
• The hepatic portal vein transports blood rich in absorbed nutrients from the small intestine to the liver
• The liver's functions include:

  • Conversion of glucose to glycogen and vice versa
  • Fat digestion
  • Metabolism of amino acids and formation of urea
  • Breakdown of alcohol
  • Breakdown of hormones
• Insulin and glucagon regulate blood glucose concentration
• Type 2 diabetes mellitus is characterized by persistently higher than normal blood glucose concentration due to the body's resistance to insulin or insufficient production of insulin
• Risk factors for type 2 diabetes mellitus include unhealthy diet and sedentary lifestyle