Nutrition in Humans

• Head area

  • Mouth
  • Buccal cavity
  • Teeth
  • Tongue
  • Salivary glands
  • Pharynx
  • oesophagus

  A) Mouth

  B) Buccal cavity

  C) Teeth

  D) Tongue

  E) Salivary glands

  F) Pharynx

  G) Oesophagus

  
• Mid to Lower area

  • Diaphragm
  • Liver
  • Gall bladder
  • Bile duct
  • Small intestine - duodenum and ileum
  • Large intestine - Colon, Rectum and Anus
  • Stomach
  • Pancreas

  A) Diaphragm

  B) Liver

  C) Gall bladder

  D) Bile duct

  E) Duodenum

  F) Ileum

  G) Stomach

  H) Pancreas

  I) Colon

  J) Rectum

  K) Anus

  
• Nutrition is the process by which organisms take in food for energy for growth, repair and maintenance of the body
• Ingestion is the intake of food
• Digestion is when large food molecules are broken down into smaller molecules that can be absorbed into the body
• Absorption is the process when nutrients move from the small intestine into the blood stream
• Head

  • Buccal cavity
  • Tongue
  • Epiglottis
  • Glottis
  • Trachea
  • Pharynx
  • Oesophagus
  • Larynx

  A) Buccal cavity

  B) Tongue

  C) Epiglottis

  D) Glottis

  E) Trachea

  F) Pharynx

  G) Oesophagus

  H) Larynx

  
• Epiglottis acts as a valve to prevent food from reaching the larynx and reaching the trachea
• The Oesophagus consists of circular muscles ( inner layer ) and longitudinal muscles ( outer layer ). These muscles are present all the way to the rectum.
• Peristalsis is the rhythmic contraction of the muscles of the alimentary canal. It propels food along the gut.
• The circular and longitudinal muscles are antagonistic. When one contracts, the other relaxes. the movement of bolus is similar to a toothpaste tube.
• Table of Stuff

  A) Salivary glands

  B) Gastric glands

  C) Liver

  D) Pancreas

  E) Epithelial cells

  
• Nutrients are absorbed in the small intestine via small finger like projections known as villi. The villus is made up of a one cell thick wall known made up of epithelial cells. These cells also have many microvilli which increase the surface area for absorption. Each villus has many blood capillaries and a lacteal. The capillaries allow for transport of glucose and amino acids into the bloodstream. Fatty acids and glycerol enter via diffusion and are transported by the lacteal. Epithelial cells also contain much Mitochondria to provide energy for active transport of nutrients.
• Assimilation is the process by which some nutrients are converted into new cytoplasm
• the hepatic portal vein transports nutrients from the small intestine to the liver. After passing the liver, the hepatic vein distributes remaining nutrients throughout the body.
• The hepatic artery supplies the liver with oxygenated blood.
• Excess glucose is stored as glycogen in the liver.
• Excess amino acids have their amino groups removed and are converted to urea in a process known as deamination. Urea is removed from the body as urine.
• Excess fats are converted into protoplasm like the cell membrane or are converted into energy when glucose levels are low.
• Islets of Langerhans secretes the hormone glucagon to increase blood glucose levels by triggering the breakdown of glycogen into glucose and insulin to reduce blood sugar levels by triggering the conversion of glucose into glycogen.
• Alcohol is broken down by alcohol hydrogenases to form acetaldehyde in the liver.
• Hormones are small secretions from the endocrine glands that travel through the bloodstream to target organs.
• Liver cirrhosis is the break down of liver cells and the formation of fibrous tissue in its place cause by excess consumption of alcohol.
• Alcohols effects on a person

  • Slowed brain function
  • Reduced self control
  • Effect on reaction time
  • Dementia
  • Shrinkage of brain volume