digestive system Flashcards
proteins
what are the macromolecules
lipids
carbohydrates
4 stages of digestive system
ingestion
digestion
absorption
egestion
mechanical digestion
chemical digestion
peristalsis
muscular contractions of the digestive tracts; brings food down
involvement and structure of the stomach
pH (stomach)
pH 2-3
sphincters
rugae
gastric juices
mucosa cells of the stomach secrete enzymes, mucus and HCL forming gastric juices
involvement and structure of the small intestine
7m long
involvement and structure of the large intestine
enzymes involved in digestion
cardiac sphincter
helps to keep food in the stomach
mucus
helps to protect the stomach lining
food and gastric juices
chyme- vomitting and consistency
pyloric sphincter
allows food to be released into the small intestine
villi (SI)
microvilli (SI)
pH (SI)
pH 9
triglycerides
glycerol and 3 fatty acids
Function of Digestive System.
1. Mouth
-mechanical digestion begins
- The jaw muscles contract causing teeth to cut, tear and
grind food
-The incisors cut food, the canine tear food, the premolars
and molars grind food
-Saliva produced in the salivary gland moistens food and
adds enzyme amylase 🡪 breaks down starch to maltose
Function of Digestive System
2. Tongue
helps to form the food and saliva into a bolus which is then swallowed and enters the esophagus
Function of Digestive System
3. Pharynx
-The large area at the back of
the mouth
-Passageway from mouth to
esophagus
-Also a common passageway
of the food and air
Function of the Digestive System
4. Esophagus
-Hollow tube lined with
mucus-secreting cells
called mucosa
-Lined with involuntary
smooth muscles
-Moves food along by
rhythmic wave-like
contractions called
peristalsis
-Esophagus connects the
pharynx and stomach
Function of Digestive System
5. Stomach
- The food enters the stomach by the cardiac sphincter, which helps to keep food in the stomach
- Mechanical digestion takes place ->churn the food
- The mucosa cells of the stomach secrete enzymes, mucus and HCl forming the gastric juice
• In presence of HCl, enzyme pepsinogen (inactive) is converted to pepsin (active).
• Pepsin is the enzyme that aids in the breakdown of proteins
• The food + gastric juice = chyme
• The pyloric sphincter allows food to be released into the small intestin
Function of the Digestive System
9.Small intestine ( duodenum)
- Duodenum produces enzymes like peptidase break peptides into amino acids;
- disaccharidases - break down disaccharides into monosaccharides
Function of the Digestive System
7. Small intestine (jejunum)
- Absorption of small molecules occurs
Function of Digestive System
8. Small Intestine (ileum )
- Absorption occurs by diffusion and active transport
Function of the Digestive System
9. Large Intestine
- Absorption of water occurs here
•Prepares wastes for elimination
•Anaerobic bacteria in colon produces vitamins (folic acid, various B vitamins & vitamin K) that gets absorbed into the bloodstream
Function of Digestive System
10. Rectum
- Storage of solid indigestible waste
Function of Digestive system
6. Liver
- Converts glucose into glycogen and stores it
• Produces bile which is stored in the gall bladder
• Bile contains bile salts which can emulsify lipids/fats.
• Release of bile salts is triggered by presence of fats in the duodenum
Function of the Digestive System
Gallbladder
- Produces bile which is stored in the gall bladder
• Bile contains bile salts which can emulsify lipids/fats.
• Release of bile salts is triggered by presence of fats in the duodenum
Function of the digestive system
Pancreas 
- Sac-like organ that produces pancreatic juice secreted into the duodenum
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