A&P - Chapter 40 (Part 3) Flashcards
What is fat broken down into? (2)
- Glycerol
2. Fatty acids
What must happen to fats before getting digested?
Emulsified by bile
What does bile contain?
No enzymes
Pancreatic lipase
Changes emulsified fats to fatty acids and glycerol in the small intestine
Digestive secretions
The release of various substances from the exocrine glands that serve the digestive system
What are examples of digestive secretions? (5)
- Saliva
- Gastric juice
- Pancreatic juice
- Bile
- Intestinal juice
What is saliva secreted by?
Salivary glands
What does saliva contain? (2)
- Mucus
- Enzymes
- mostly amylase
What does mucus from the saliva do?
Lubricates and mixes with food
What is the main enzyme in saliva?
Amylase
What pH does amylase function best at?
Alkaline
- acidic
What is gastric juice secreted by?
Exocrine gastric glands in the stomach
Pepsin
Protease that begins digestion of proteins
HCl
Decreases pH of chyme to a level that activates and optimizes pepsin activity
What is required for vitamin B12 absorption?
Intrinsic factors
What does mucus and water do? (3)
- Lubricate
- Protect
- Help with the mixing of chyme
What secretes pancreatic juices?
The exocrine parts of the pancreas
What are the enzymes that the pancreas secretes? (4)
- Proteases
- Lipases
- Nucleases
- Amylase
What does the pancreas secrete?
Sodium bicarbonate
What does sodium bicarbonate do? (3)
- Buffers stomach contents that enter into the duodenum
- Increase pH for optimum enzyme function
- Plays a role in maintaining blood pH
Where is bile secreted? Store?
- Liver
2. GB
What does bile contain?
- Lecithin
- Bile salts
- which emulsify fat in preparation for digestion by lipases
What is an unique property of bile?
Hydrophobic and hydrophilic properties
- micelles
What is the release of bile initiated by?
The presence of fat in chyme
What does the detection of fat in chyme stimulate the release of?
The hormone cholecystokinin (CCK) from the duodenum’s intestinal mucosa
- CCK –> contraction of the GB –> bile is secreted into the duodenum
What is intestinal juices secreted by?
Cells of the intestinal exocrine glands
What does sodium bicarbonate do?
It increases the pH to optimize enzyme function
What is salivary secretion controlled by?
Reflex mechanism
- stimulated from the presence of food
What stimuli is involved with salivary secretions?
- Olfactory
2. Visual
