CHAPTER 7 STUDY GUIDE
1. Structure and function of the GI tract (alimentary canal)
1. structure
1. Long muscular tube extending from mouth to anus
2. UPPER GI TRACT: mouth esophagus and stomach
3. middle GI tract: duodenum, jejunum, ileum
4. lower GI tract: cecum, colon, rectum
5. accessory organs: salivary glands, liver, pancreas
2. function
1. To digest food and absorb nutrients into the blood stream.
2. Mouth: begins digestion with mastication.
3. Saliva: lube food, aids in food breakdown
1. contains salivary amylase to break down carbs and lipase to break
down fats
4. Esophagus: passes food from pharynx to stomach
1. smooth muscle layers that use peristalsis
5. Pharyngoesophageal sphincter:
1. loc. in upper esophagus and prevents air from entering esophagus
and stomach during breathing.
6. Gastroesophageal sphincter:
1. Loc. in lower region of the esophagus connecting it to stomach.
Prevents re ux of gastric contents into esophagus.
7. Stomach:
1. holds food during early stages of digestion. Carb and protein
digestion (by pepsin) occur here. (Think pepsid complete—antacid).
1. Cardiac Region: Where esophagus opens to stomach.
2. Fundus: Upper dome shaped region.
3. Body: Middle portion.
4. Pyloric Region: Connects stomach to small intestine
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, 1. Pyloric Sphincter: Controls the emptying of stomach contents
into small intestine. Prevents back ow into the stomach.
8. Small intestine:
1. where the majority of digestion and absorption takes place.
1. Duodenum: 10 inches long.
2. Jejunum
3. Ileum: Jejunum and Ileum both equal 9-20 feet depending on size
of person.
4. Bile enters through common bile duct
5. Pancreatic Juices enter through main pancreatic duct
6. Emulsi cation: fat getting broken down into smaller pieces so
that water soluble digestive enzyme can act on the surface
molecules. starts in stomach with agitation(mechanical digestion)
and continues in duodenum with help from bile and pancreatic
lipase (chemical digestion).
7. Small intestine contains a large surface area with villi and circular
folds for max absorption of nutrients.
9. Large Intestine: 4.5-5 ft long. 2.4-2.7. Reabsorbs mainly water and
serves as storage for waste until defecation occurs.
1. Cecum
2. Colon:
1. Ileocecal Valve: Loc. at the cecum and prevents feces fro owing
back into ileum
2. Divided into:
1. Ascending, transverse, and sigmoid sections.
3. Rectum:
1. Connects sigmoid colon to anus.
4. Anal Canal:
1. Has strong sphincter muscles to prevent incontinence.
10.Liver:
1. Stores 500-1000mL of blood (helpful during hypervolemia as this can
be moved back into circulation.
2. Produces bile. needed for dietary fat digestion and absorption.
3. metabolizes hormones and drugs
4. synthesizes proteins, glucose and clotting factors
5. stores vitamins and minerals and converts them to be usable by the
body
6. changes ammonia to urea
7. converts fatty acids to ketones
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1. Structure and function of the GI tract (alimentary canal)
1. structure
1. Long muscular tube extending from mouth to anus
2. UPPER GI TRACT: mouth esophagus and stomach
3. middle GI tract: duodenum, jejunum, ileum
4. lower GI tract: cecum, colon, rectum
5. accessory organs: salivary glands, liver, pancreas
2. function
1. To digest food and absorb nutrients into the blood stream.
2. Mouth: begins digestion with mastication.
3. Saliva: lube food, aids in food breakdown
1. contains salivary amylase to break down carbs and lipase to break
down fats
4. Esophagus: passes food from pharynx to stomach
1. smooth muscle layers that use peristalsis
5. Pharyngoesophageal sphincter:
1. loc. in upper esophagus and prevents air from entering esophagus
and stomach during breathing.
6. Gastroesophageal sphincter:
1. Loc. in lower region of the esophagus connecting it to stomach.
Prevents re ux of gastric contents into esophagus.
7. Stomach:
1. holds food during early stages of digestion. Carb and protein
digestion (by pepsin) occur here. (Think pepsid complete—antacid).
1. Cardiac Region: Where esophagus opens to stomach.
2. Fundus: Upper dome shaped region.
3. Body: Middle portion.
4. Pyloric Region: Connects stomach to small intestine
fl
, 1. Pyloric Sphincter: Controls the emptying of stomach contents
into small intestine. Prevents back ow into the stomach.
8. Small intestine:
1. where the majority of digestion and absorption takes place.
1. Duodenum: 10 inches long.
2. Jejunum
3. Ileum: Jejunum and Ileum both equal 9-20 feet depending on size
of person.
4. Bile enters through common bile duct
5. Pancreatic Juices enter through main pancreatic duct
6. Emulsi cation: fat getting broken down into smaller pieces so
that water soluble digestive enzyme can act on the surface
molecules. starts in stomach with agitation(mechanical digestion)
and continues in duodenum with help from bile and pancreatic
lipase (chemical digestion).
7. Small intestine contains a large surface area with villi and circular
folds for max absorption of nutrients.
9. Large Intestine: 4.5-5 ft long. 2.4-2.7. Reabsorbs mainly water and
serves as storage for waste until defecation occurs.
1. Cecum
2. Colon:
1. Ileocecal Valve: Loc. at the cecum and prevents feces fro owing
back into ileum
2. Divided into:
1. Ascending, transverse, and sigmoid sections.
3. Rectum:
1. Connects sigmoid colon to anus.
4. Anal Canal:
1. Has strong sphincter muscles to prevent incontinence.
10.Liver:
1. Stores 500-1000mL of blood (helpful during hypervolemia as this can
be moved back into circulation.
2. Produces bile. needed for dietary fat digestion and absorption.
3. metabolizes hormones and drugs
4. synthesizes proteins, glucose and clotting factors
5. stores vitamins and minerals and converts them to be usable by the
body
6. changes ammonia to urea
7. converts fatty acids to ketones
fi fl fl
