NUTRITION

1
NUTRITION

• DIGESTION

2
DIGESTION

• There are 2 processes involved in digestion
• Mechanical
• Physical breakdown of food (chewing, stomach
  muscle contraction)
• Chemical
• Chemicals act on the food to assist with digestion

3
MOUTH

• Mechanical mastication (chewing)
• Chemical mostly enzymes in the saliva
• Ptyalin acts on starches
• Lingual lipase acts on fats
• Note protein digestion is only mechanical in
  the mouth

4
STOMACH

• Mechanical
• Peristalsis churning of the stomach
• Chemical
• Chemical
• Hydrochloric acid breaks down all nutrients
• Gastric lipase breaks down fats
• Pepsin breaks down proteins
• Note rennin present in infants only helps to
  break down proteins

5
SMALL INTESTINE

• Primary absorption of nutrients occurs here
• Mechanical
• Peristaltic waves move the food along
• Segmentation rings contract and relax to chop
  the food
• Pendular movements, longitudinal rotation, and
  surface villi stir and mix the food

6
SMALL INTESTINE

• Chemical digestion primarily occurs here
• Intestinal secretions
• Sucrase, lactase, maltase, pancreatic amylase all
  break down carbohydrates
• Intestinal lipase breaks down fats
• Enterokinase assist with break down of protein
• Amino peptidase breaks off the end amino acids
  from proteins

7
SMALL INTESTINE

• Accessory organs
• organs outside the alimentary canal that secrete
  chemicals into the small intestine
• Gall bladder secrete bile breaks down fat
• Pancreas
• secretes pancreatic lipase and cholesteral
  enterase breaks down fat and cholesterol
• Secretes trypsin, chymotrypsin, carboxypeptidase
  all help break down protein

8
LARGE INTESTINE

• Primary responsibility is the absorption of water