Digestive System Process

Mouth and Esophagus

• Mechanical Breakdown: Teeth chew food into smaller pieces, increasing surface area for enzyme action
• Chemical Breakdown: Saliva contains amylase, breaking down carbohydrates into simple sugars
• Swallowing: Food mixed with saliva forms a bolus, which is swallowed, passing through the pharynx and into the esophagus
• Peristalsis: Muscular contractions propel food through the esophagus and into the stomach

Liver and Pancreas Function

• Liver:
  • Produces bile, stored in the gallbladder, which emulsifies fats
  • Regulates blood sugar levels by storing and releasing glucose
  • Detoxifies the blood by removing waste and toxins
• Pancreas:
  • Produces digestive enzymes, such as amylase, lipase, and trypsin, which break down carbohydrates, fats, and proteins
  • Regulates blood sugar levels by producing insulin and glucagon

Stomach and Gastric Digestion

• Gastric Juice: Mix of hydrochloric acid, pepsin, and mucus
• Protein Breakdown: Pepsin breaks down proteins into smaller peptides and amino acids
• Gastric Mixing: Muscular contractions mix food with gastric juice, breaking down proteins and releasing nutrients
• Gastric Emptying: Partially digested food, chyme, enters the small intestine

Small Intestine and Absorption

• Most nutrient absorption occurs here
• Microvilli: Finger-like projections increase surface area for absorption
• Brush Border Enzymes: Break down carbohydrates, proteins, and fats into absorbable nutrients
• Absorption: Nutrients absorbed into the bloodstream, transported to the liver for processing and distribution

Large Intestine and Rectum

• Water and Electrolyte Absorption: The large intestine absorbs water and electrolytes, regulating the body's water balance
• Feces Formation: Water and electrolyte absorption creates a solid waste, feces, which is stored in the rectum
• Defecation: Feces eliminated from the body through the anus

Macromolecules

• Carbohydrates: Broken down into simple sugars (e.g., glucose) for energy production
• Proteins: Broken down into amino acids for energy production, growth, and repair
• Fats: Broken down into fatty acids and glycerol for energy production
• Nucleic Acids: Broken down into nucleotides for energy production and genetic material synthesis

Mouth and Esophagus

• Teeth mechanically break down food into smaller pieces, increasing surface area for enzyme action
• Saliva contains amylase, which breaks down carbohydrates into simple sugars
• The mixture of food and saliva forms a bolus, which is swallowed and passes through the pharynx and into the esophagus
• Peristalsis, a series of muscular contractions, propels the bolus through the esophagus and into the stomach

Liver and Pancreas Function

• The liver produces bile, stored in the gallbladder, which emulsifies fats
• The liver regulates blood sugar levels by storing and releasing glucose
• The liver detoxifies the blood by removing waste and toxins
• The pancreas produces digestive enzymes, such as amylase, lipase, and trypsin, which break down carbohydrates, fats, and proteins
• The pancreas regulates blood sugar levels by producing insulin and glucagon

Stomach and Gastric Digestion

• Gastric juice is a mix of hydrochloric acid, pepsin, and mucus
• Pepsin breaks down proteins into smaller peptides and amino acids
• Gastric mixing involves muscular contractions that mix food with gastric juice, breaking down proteins and releasing nutrients
• Partially digested food, chyme, enters the small intestine through gastric emptying

Small Intestine and Absorption

• Most nutrient absorption occurs in the small intestine
• Microvilli increase the surface area for absorption
• Brush border enzymes break down carbohydrates, proteins, and fats into absorbable nutrients
• Nutrients are absorbed into the bloodstream and transported to the liver for processing and distribution

Large Intestine and Rectum

• The large intestine absorbs water and electrolytes, regulating the body's water balance
• Water and electrolyte absorption creates a solid waste, feces, which is stored in the rectum
• Feces are eliminated from the body through the anus during defecation

Macromolecules

• Carbohydrates are broken down into simple sugars (e.g., glucose) for energy production
• Proteins are broken down into amino acids for energy production, growth, and repair
• Fats are broken down into fatty acids and glycerol for energy production
• Nucleic acids are broken down into nucleotides for energy production and genetic material synthesis

Mouth and Esophagus

• Mechanical breakdown of food occurs in the mouth through chewing
• Saliva containing enzyme amylase breaks down carbohydrates into simpler sugars
• Formed bolus is swallowed, passing through the pharynx and into the esophagus
• Esophagus uses peristalsis to propel the bolus into the stomach

Stomach and Gastric Digestion

• Stomach secretes gastric juices containing pepsin, HCl, and mucus
• Pepsin breaks down proteins into smaller peptides and amino acids
• HCl provides an acidic environment for pepsin to work effectively
• Mucus protects the stomach lining from acid and enzymes
• Stomach churns and mixes food with gastric juices for about an hour

Small Intestine and Absorption

• Partially digested food (chyme) enters the small intestine
• Walls of small intestine are lined with villi and microvilli, increasing surface area for absorption
• Nutrients are absorbed into the bloodstream through the walls of the small intestine
• Absorbed nutrients are transported to the liver for processing

Large Intestine and Rectum

• Remaining waste products enter the large intestine (colon)
• Water and electrolytes are absorbed in the large intestine
• Large intestine is home to a diverse community of microbiota
• Waste becomes more solid as it moves through the colon and eventually forms feces
• Feces are stored in the rectum until eliminated through the anus

Liver and Pancreas Function

• Liver produces bile, which emulsifies fats and helps with fat absorption
• Liver regulates blood sugar levels and detoxifies the blood
• Pancreas produces digestive enzymes, such as amylase, lipase, and trypsin
• Pancreas regulates blood sugar levels

Macromolecules

• Carbohydrates are broken down into simple sugars (e.g., glucose) in the mouth and small intestine
• Carbohydrates are absorbed into the bloodstream and transported to the liver for processing
• Proteins are broken down into amino acids in the stomach and small intestine
• Proteins are absorbed into the bloodstream and used for various bodily functions
• Lipids are broken down into fatty acids and glycerol in the small intestine
• Lipids are absorbed into the bloodstream and transported to the liver for processing