OSSF II - Exam 2 questions with verified answers
graded A+ updated
1. Explain the
The function of the GI tract is digestion!!
ma- jor
Macromolecules in food cannot be directly absorbed from the G.I. tract
functions of
so they must be degraded into monomers to be absorbed. Once
the
absorbed, they are synthesized back into macromolecules to be used
gastrointesti-
as an energy source. This process of breakdown and resynthesis is so
nal (GI) tract
that it avoids the immune system from recognizing the ingested
proteins as foreign.
There are 4 main processes of digestion (not necessarily sequentially)
1. Mechanical processing
Chewing ’increase surface area of particles available for enzymatic
degradation
**the chewing muscles and the external anal sphincter are the only
muscles under voluntary control in the GI tract, the rest are passive**
Alternating contraction/relaxation of stomach & small intestine ’mix content
to enhance the eflciency of enzymatic degradation
2. Secretion of enzyme-containing digestive juices: Produced by
epithelial cells in the gastric & intestinal mucosa and glands/organs
outside the digestive tract (the composition and pH are adapted to the
enzymes present)
--> this includes the production of endocrine factors that will also be
secreted somewhere else in the GI tract
--> Goblet cells in epithelial cells also produce mucus to protect intestinal
epithelial cells from injury and lubricate the intestinal contents
--> Water, ions, and proteins are secreted and then absorbed and
recirculated
3. Enzymatic breakdown of organic nutrients: enzymes catalyze the
breakdown of polymers (carbohydrates, lipids and proteins) into
monomers by hydrolysis
--> happens in a step-wise function where ditterent regions of GI tract
,OSSF II - Exam 2 questions with verified answers
graded A+ updated
secrete ditterent enzymes
to keep breaking it down
further and further
4. Absorption
--> Small molecules
(monomers), water, ions,
and vitamins are
transported from the
digestive tract lumen to the
blood or lymph capillaries
--> Nutrients cross the
epithelial cells of the
intestinal mucosa by active
transport and dittusion
,OSSF II - Exam 2 questions with verified answers
graded A+ updated
2. Describe the Mammalian digestive tract anatomy:
ma- jor Digestive tract **food taken in, things are absorbed, waste is secreted**
anatomical 1. Oral cavity
structures of 2. Pharynx
the digestive
tract
with emphasis on 3. Esophagus
differences
be- tween
species 3. Review important concepts related
, OSSF II - Exam 2 questions with verified answers
graded A+ updated
4. Fermentation small intestine. The primary location of absorption is the small intestine
chamber (ruminants only and some in the large intestine.
- breaking down
carbohydrates from
plants w/ enzymes that
carnivores don't have)
5. Stomach (expandable
in carnivores)
6. Small intestine
--> Duodenum
--> Jejunum
--> Ileum
7. Large intestine
--> Cecum
--> Colon (ascending,
transverse, descending)
8. Rectum
Structures outside the
digestive tract with secretory
functions
• Salivary glands
• Pancreas
• Liver & Gallbladder
Most of the secretion
occurs in the stomach and
small intestine. These
secretions are from glands
outside the GI tract
(salivary, pancreas, liver)
and glands in the gastric
mucosa and crypts of the
graded A+ updated
1. Explain the
The function of the GI tract is digestion!!
ma- jor
Macromolecules in food cannot be directly absorbed from the G.I. tract
functions of
so they must be degraded into monomers to be absorbed. Once
the
absorbed, they are synthesized back into macromolecules to be used
gastrointesti-
as an energy source. This process of breakdown and resynthesis is so
nal (GI) tract
that it avoids the immune system from recognizing the ingested
proteins as foreign.
There are 4 main processes of digestion (not necessarily sequentially)
1. Mechanical processing
Chewing ’increase surface area of particles available for enzymatic
degradation
**the chewing muscles and the external anal sphincter are the only
muscles under voluntary control in the GI tract, the rest are passive**
Alternating contraction/relaxation of stomach & small intestine ’mix content
to enhance the eflciency of enzymatic degradation
2. Secretion of enzyme-containing digestive juices: Produced by
epithelial cells in the gastric & intestinal mucosa and glands/organs
outside the digestive tract (the composition and pH are adapted to the
enzymes present)
--> this includes the production of endocrine factors that will also be
secreted somewhere else in the GI tract
--> Goblet cells in epithelial cells also produce mucus to protect intestinal
epithelial cells from injury and lubricate the intestinal contents
--> Water, ions, and proteins are secreted and then absorbed and
recirculated
3. Enzymatic breakdown of organic nutrients: enzymes catalyze the
breakdown of polymers (carbohydrates, lipids and proteins) into
monomers by hydrolysis
--> happens in a step-wise function where ditterent regions of GI tract
,OSSF II - Exam 2 questions with verified answers
graded A+ updated
secrete ditterent enzymes
to keep breaking it down
further and further
4. Absorption
--> Small molecules
(monomers), water, ions,
and vitamins are
transported from the
digestive tract lumen to the
blood or lymph capillaries
--> Nutrients cross the
epithelial cells of the
intestinal mucosa by active
transport and dittusion
,OSSF II - Exam 2 questions with verified answers
graded A+ updated
2. Describe the Mammalian digestive tract anatomy:
ma- jor Digestive tract **food taken in, things are absorbed, waste is secreted**
anatomical 1. Oral cavity
structures of 2. Pharynx
the digestive
tract
with emphasis on 3. Esophagus
differences
be- tween
species 3. Review important concepts related
, OSSF II - Exam 2 questions with verified answers
graded A+ updated
4. Fermentation small intestine. The primary location of absorption is the small intestine
chamber (ruminants only and some in the large intestine.
- breaking down
carbohydrates from
plants w/ enzymes that
carnivores don't have)
5. Stomach (expandable
in carnivores)
6. Small intestine
--> Duodenum
--> Jejunum
--> Ileum
7. Large intestine
--> Cecum
--> Colon (ascending,
transverse, descending)
8. Rectum
Structures outside the
digestive tract with secretory
functions
• Salivary glands
• Pancreas
• Liver & Gallbladder
Most of the secretion
occurs in the stomach and
small intestine. These
secretions are from glands
outside the GI tract
(salivary, pancreas, liver)
and glands in the gastric
mucosa and crypts of the
