Digestive system Anatomy & physiology Flashcards
What is the digestive system composed of?
The GI tract starting from the mouth and ending with the anus (rectum).
What are the parts of the GI tract:
- Mouth
- Pharynx
- Esophagus
- Stomach
- Small intestine
- Large intestine
- Rectum
Where does the digestion of food begin?
The mouth; by chewing and mechanically digesting it.
What does mucus and saliva aid the digestion of food?
mucus and saliva lubricates the food and enzymes with amylase and lipase
Mechanical digestion:
physical breakdown of food: ex chewing
mucus and saliva lubricates the food and enzymes with amylase and lipase which initiates the chemical digestion of:
Starches and Lipids
What is the second step of digestion?
Once the food has been mechanically digested, it then travels down the pharynx and into the esophagus.
What is peristalsis?
Peristalsis is the contraction of muscles that occur within the esophagus to help food move down into the stomach.
Third step of digestion:
Now that peristalsis has occurred, food can travel into the stomach
What is the shaped of the stomach?
J- shaped sack.
What does the stomach initiate:
Additional chemical digestion with enzymes
What does gastric acid do?
Kills bacteria, denatures proteins, and activates digestive enzymes.
Fourth step of digestion:
Small intestine
Where is the main site of digestion and absorption in the digestive system?
The small intestine: Composed of duodenum, jejunum, and ileum.
What is the shape of the small intestine, how does it promote absorption?
The small intestine is coiled, and has a series of foldings that increase the surface area for absorption.
What is the fifth step of The digestive system?
Large intestine
What is the Large intestine composed of?
cecum, colon, rectum.
What does the large intestine do?
The large intestine absorbs water, electrolytes, and vitamins produced by the enteric bacteria.
What is the final step of the GI tract?
Rectum: stores feces
How are feces eliminated?
Through defecation
What are the accessory organs of the digestive system?
Teeth, tongue, salivary gland, liver, gallbladder, and pancreas.
What are enzymes and hormones of the digestive system?
Gastrin, CCK, Secretin, Insulin, Glucagon, and Bile.
Gastrin:
Hormone Produced in the stomach and stimulates stomach acid.
Cholecystokinin (CCK):
Hormone Produced in the small intestine and stimulates the release of enzymes from the pancreas and bile from the liver.
Secretin:
Hormone Produced in the small intestine and stimulates the production of bicarbonate by the pancreas.
Insulin:
Hormone Produced in the pancreas and regulates blood sugar levels
Bile:
Produced by the liver and stored in the gallbladder- helps break down fat in the small intestine.
Glucagon
Hormone Produced the in the pancreas and helps to release glucose from the liver.
