BIO 269 QUESTIONS AND ANSWERS LATEST UPDATE 100%
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The alimentary canal is also known as...
The gastrointestinal (GI) tract
What organs are part of the GI tract?
Mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus
What are the accessory organs?
Teeth, tongue, salivary glands, liver, gallbladder, pancreas
What do the salivary glands do?
Moisten, lubricate, and breakdown carbs and fats
What does the pancreas do?
Enzymes are secreted into the duodenum that neutralize stomach acid
What does the liver do?
Secrete bile into duodenum, breakdown fats, neutralize stomach acid
What does the gallbladder do?
Stores bile made by the liver
What are the 6 steps of digestion?
1. Ingestion
2. Propulsion
3. Mechanical breakdown
4. Digestion
5. Absorption
6. Defecation
Why is the small intestine important?
It is a major site for digestion and absportion
What are the 4 layers of the small intestine from inside-->out?
- Mucosa
- Submucosa
- Muscularis externa
- Serosa
What do the intestinal villi and microvilli do?
Increase surface area available for absorption
What is the difference between intestinal villi and microvilli?
Intestinal villi are finger like projections (1mm high)
Microvilli are long and densely packed
What is mastication?
Chewing
What is deglutination?
Swallowing
What are the 3 phases of deglutination?
1. Buccal
2. Pharyngeal
3. Esophageal
, What does the upper esophageal sphincter do?
Ensures breathing happens
What does the lower esophageal sphincter do?
Prevents acid reflux
How long does food passage to the stomach take?
8 seconds
Food in the stomach in converted into what?
Chyme
What are the 2 motor functions of the stomach?
1. Receptive relaxation (stomach relaxes and stretches)
2. Gastric peristalasis
How long does gastric emptying take?
4 hours
Events in the _________ regulate gastric motility (peristalsis) and emptying.
Duodenum
What are the 3 parts of the small intestine?
- Duodenum
- Jejunum
- Ileum
What is segmentation?
The mixing of chyme, bile, and intestinal juices through random contractions in the
canal
How long does segmentation take?
3-6 hours
What is the neural control of the small intestine?
PNS releases acetylcholine that increases motility
SNS releases norepinephrine to decrease motlity
What is the hormonal control of the small intestine?
Gastrin increases motility
What does the ileocecal valve do?
- Separates small and large intestine
- Prevents backflow
- Opens upon pressure differences
What are the 2 types of contractions in the large intestine?
1. Haustral contractions (every 30 mins)
2. Mass movement (stronger slower contracts 3-4 a day that push contents toward
rectum)
What are the 3 steps to defecation?
1. Feces enter rectum and stretch walls
2. PNS contracts rectum and relaxes internal sphincter
3. External sphincter opens with voluntary control
Saliva secretion is primarily controlled by ____________ influence.
Parasypathetic
What is the composition of saliva?
CORRECT A+ GRADED. Buy Quality Materials!
The alimentary canal is also known as...
The gastrointestinal (GI) tract
What organs are part of the GI tract?
Mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus
What are the accessory organs?
Teeth, tongue, salivary glands, liver, gallbladder, pancreas
What do the salivary glands do?
Moisten, lubricate, and breakdown carbs and fats
What does the pancreas do?
Enzymes are secreted into the duodenum that neutralize stomach acid
What does the liver do?
Secrete bile into duodenum, breakdown fats, neutralize stomach acid
What does the gallbladder do?
Stores bile made by the liver
What are the 6 steps of digestion?
1. Ingestion
2. Propulsion
3. Mechanical breakdown
4. Digestion
5. Absorption
6. Defecation
Why is the small intestine important?
It is a major site for digestion and absportion
What are the 4 layers of the small intestine from inside-->out?
- Mucosa
- Submucosa
- Muscularis externa
- Serosa
What do the intestinal villi and microvilli do?
Increase surface area available for absorption
What is the difference between intestinal villi and microvilli?
Intestinal villi are finger like projections (1mm high)
Microvilli are long and densely packed
What is mastication?
Chewing
What is deglutination?
Swallowing
What are the 3 phases of deglutination?
1. Buccal
2. Pharyngeal
3. Esophageal
, What does the upper esophageal sphincter do?
Ensures breathing happens
What does the lower esophageal sphincter do?
Prevents acid reflux
How long does food passage to the stomach take?
8 seconds
Food in the stomach in converted into what?
Chyme
What are the 2 motor functions of the stomach?
1. Receptive relaxation (stomach relaxes and stretches)
2. Gastric peristalasis
How long does gastric emptying take?
4 hours
Events in the _________ regulate gastric motility (peristalsis) and emptying.
Duodenum
What are the 3 parts of the small intestine?
- Duodenum
- Jejunum
- Ileum
What is segmentation?
The mixing of chyme, bile, and intestinal juices through random contractions in the
canal
How long does segmentation take?
3-6 hours
What is the neural control of the small intestine?
PNS releases acetylcholine that increases motility
SNS releases norepinephrine to decrease motlity
What is the hormonal control of the small intestine?
Gastrin increases motility
What does the ileocecal valve do?
- Separates small and large intestine
- Prevents backflow
- Opens upon pressure differences
What are the 2 types of contractions in the large intestine?
1. Haustral contractions (every 30 mins)
2. Mass movement (stronger slower contracts 3-4 a day that push contents toward
rectum)
What are the 3 steps to defecation?
1. Feces enter rectum and stretch walls
2. PNS contracts rectum and relaxes internal sphincter
3. External sphincter opens with voluntary control
Saliva secretion is primarily controlled by ____________ influence.
Parasypathetic
What is the composition of saliva?
