Clin Phys 8 - GI Tract

Question 1

what is the alimentary canal?

Answer 1

tubular structure that makes direct contact with food and has a typical set of histologic layers that surround a lumen

Question 2

what is the alimentary canal composed of?

Answer 2

• oral cavity and pharynx
• esophagus
• stomach
• small intestine
• large intestine

Question 3

what are the accessory digestive organs?

Answer 3

• salivary glands
• liver and gall bladder
• pancreas

Question 4

what do accessory digestive organs do?

Answer 4

they secrete substances into the alimentary canal

Question 5

what does the alimentary canal do?

Answer 5

-propulsion: move food along
- secretion: hormones
- digestion
- absorption
- immune function

Question 6

what are the layers of the alimentary canal

Answer 6

• mucosa
• muscularis mucosa
• submucosa
• muscularis
• outer layer -adventita or serosa
• peritoneal cavity

Question 7

explain what is in the mucosa layer

Answer 7

epithelial lining, lamina propria, muscularis mucosa

Question 8

lamina propria is the site of:

Answer 8

blood, lymphatic vessels, and immune tissue

Question 9

what does muscularis mucosa do?

Answer 9

alters the shape of the mucosa to optimize mixing and exposure of the epithelial cells to lumen contents

Question 10

what is the submucosa?

Answer 10

loose CT with larger blood vessels and lymphatics

Question 11

there is a plexus of neurons in the submucosa known as?

Answer 11

Meissner’s plexus which regulate secretions and convey sensory info about what’s in the lumen

Question 12

how many layers are there for the muscularis?

Answer 12

inner and outer layer

Question 13

explain the inner layer of the muscularis?

Answer 13

“circular layer” - smooth muscle fibres concentrically surround the lumen , when it contracts, it “squeezes” the lumen shut

Question 14

explain the outer layer of the muscularis?

Answer 14

“longitudinal layer” - smooth muscle fibres run along the length of the canal and when it contracts, it “shortens” the canal

Question 15

what is the plexus called in the muscularis?

Answer 15

Auerbach or myenteric plexus - regulates the movements of these muscular layers

Question 16

what is in the outer layer

Answer 16

adventita or serosa

Question 17

explain adventitia

Answer 17

in the esophagus - connective tissue that anchors the esophagus in the chest cavity

Question 18

explain serosa

Answer 18

loose connective tissue that is covered by a simple squamous mesothelium

Question 19

what is the peritoneal cavity?

Answer 19

fluid filled gap between the wall of the abdomen and the organs contained within the abdomen

Question 20

what is the esophagus?

Answer 20

tube that extends from the pharynx to the stomach, only role is propulsion of food to the stomach

Question 21

what is the upper esophageal sphincter?

Answer 21

when it closes, it pushes food from the pharynx to the esophagus

Question 22

what is the lower esophageal sphincter?

Answer 22

limits movement of stomach acid into the esophagus -> relaxes to receive swallowed food

Question 23

what happens in the stomach?

Answer 23

muscular movements accomplish mechanical digestion and propulsion into the small intestine
- also a role in chemical digestion , acid denatures proteins and kills ingested bacteria and secreted enzymes help to digest protein

Question 24

what is the stomach’s role in regulating food intake?

Answer 24

the stomach tells you when you’re full

Question 25

what is the pyloric sphincter?

Answer 25

regulates the amount of acidic chyme that enters the duodenum

Question 26

what is the main digestive organ in the body?

Answer 26

small intestine

Question 27

what are the 3 separate components of the small intestine?

Answer 27

- duodenum - jejunum - ileum

Question 28

the small intestine also have...

Answer 28

highly folded epithelium 9microvilli), mucosa (villi), and submucosal layers (circular folds) meant to optimize surface area

Question 29

what is the main function of the large intestine?

Answer 29

absorption of water from stool, storage of stool, and housing the majority of the microbes in the gut

Question 30

what are the roles of the liver?

Answer 30

- Carbohydrate metabolism - Protein synthesis and degradation ○ Most proteins secreted into the bloodstream are from the liver - Lipid metabolism - Detoxification of molecules so that they can be secreted into the bile and defecated - Making hydrophobic molecules water soluble so that they can be eliminated by the kidney - Storage of vitamins and minerals - Synthesis of bile - essential for lipid digestion - Endocrine - secretion of IGF-1, important hormone regulating growth

Question 31

what is the role of the gall bladder?

Answer 31

storage and modification of bile

Question 32

pancreas: exocrine

Answer 32

secretes digestive enzymes that are crucial for carbohydrate, protein, and lipid chemical digestions ○ These enzymes are secreted into the pancreatic duct, which drains into the duodenum

Question 33

pancreas: endocrine

Answer 33

secretes hormones that impact glucose, protein, and lipid metabolism into the bloodstream ○ Insulin, glucagon, and somatostatin

Question 34

explain bowel sounds increased (hyperactive)

Answer 34

○ Diarrhea, gastroenteritis, inflammatory bowel disease, laxative use, gastrointestinal bleed ○ Or early bowel obstruction (often described as a high-pitched "tinkling"sound

Question 35

explain bowel sounds decreased (hypoactive)

Answer 35

○ Often suggests more emergent conditions ○ Bowel obstruction, peritonitis, intestinal ischemia

Question 36

what does tenderness main during an abdominal physical exam

Answer 36

pain in a region where you palpate

Question 37

what is guarding

Answer 37

voluntary contraction of the abdominal musculature due to abdominal discomfort

Question 38

what is rigidity

Answer 38

involuntary contraction of the abdominal musculature, usually accompanied by severe pain

Question 39

what if you have abdominal pain in the 3 areas in teh centre

Answer 39

visceral pain from the alimentary tract or accessory organs § Can also be due to irritation of the parietal peritoneum

Question 40

what if you have abdominal pain in the 6 regions on the sides

Answer 40

often due to irritation of the parietal peritoneum § Can also be due to visceral pain from non-GI organs

Question 41

what is a hepatomegaly?

Answer 41

enlarged liver

Question 42

what is liver cirrhosis?

Answer 42

large liver with firm, nontender edge

Question 43

what is hepatocellular carcinoma?

Answer 43

large liver that is firm and an irregular edge. may or may not be tender