Exam 2/Quiz 7- Chemical & Physical Processes of Digestion Flashcards
What are the functions of the digestive system?
- Ingestion
- Digestion
- Absorption
- Elimination
What are the two forms of digestions?
- Mechanical
2. Chemical
Where does digestion begin?
Mouth
What does mechanical digestion consist of? What structures does it involve?
- Chewing, Physical breaking up of food
2. Teeth, Tongue, Palate
What does chemical digestion consist of? What is an example of it?
- Breaking down of an organic compound by enzymes
2. Hydrolysis
What are 3 things involved in chemical digestion?
- Salivary glands
- Lysozyme
- Salivary amylase
What antibody does saliva contain?
IgA
What are the 3 salivary glands?
- Parotid Glands
- Sublingual Glands
- Submandibular Glands
Lysozyme: _______
Bacteriostatic
What is the purpose of salivary amylase?
To digest startch to disaccharide
What are the two phases swallowing? (list involuntary/voluntary)
- Buccal phase (Voluntary)
2. Pharyngeal-esophageal phase (Involuntary)
Describe the peristaltic movements of digestion.
Waves of contraction followed by waves of relaxation that squeeze the foodstuffs through the alimentary canal
Describe the segmental movements of digestion. What is the purpose of these movements?
- Local constrictions of the organ wall that occur
rhythmically - Mainly to mix foodstuffs with digestive juices and to increase the rate of absorption
What does the inner lining of the stomach have? What do they secrete? What is the purpose of this?
- Gastric pits and gastric glands
- Secrete HCl
- Makes the food more acidic
What is pepsin produced by?
Stomach
Pepsinogen is converted to _____. This is by the action of ____. Pepsinogen is the ____ ____ of pepsin.
- pepsin
- HCL
- inactive form
What is pepsin/function of pepsin?
Pepsin is a protease that breaks down proteins
What is gastric juice?
Mixture of HCl and pepsin
Partially digested food = ______.
chyme
Partially digested food (Chyme) from the stomach enters the ___ ____ via the ____ ____ at the ______.
- Small Intestine
- pyloric sphincter
- Duodenum
Small Intestine: Only small in ____ but very _____.
diameter/lengthy
What are the 3 parts of the small intestine, and state their length.
1, Duodenum (10in)
- Jejunum (8ft)
- Ileum (12ft)
Maximum absorption occurs in the SI by the _____ produced and into the SI.
enzymes
What are the 3 main features of the inner lining of the small intestine?
- Plicae circulares (circular folds)
- Villi
- Brush border (microvilli)
What is the purpose of the 3 main features of the inner lining of the small intestine?
to increase the surface area for absorption of nutrients
The pancreas and liver are digestive ____ ____.
accessory organs
Source/Function:
Amylases
- Pancreas
2. Breaks down starch
Source/Function:
Trypsin
- Pancreas
2. Breaks down Proteins
Source/Function:
Lipase
- Pancreas
2. Digest Lipids
Source/Function:
HCO3- (bicarbonate)
- Pancreas
2. Neutralize stomach acid
Source/Function:
Bile
- Liver
- – Surfactant
– Emulsification
– Physically breaks down fat
What is a surfactant?
stabilizes emulsion and increases surface area
Where is bile temporarily stored?
gall bladder
What 4 chemicals does the pancreas produce?
- Amylases
- Trypsin
- Lipase
- Bicarbonate
Enzymes act on _____.
substrates
