Digestive Pt 2

Question 1

Be prepared to label the different regions and anatomical features of the stomach

Question 2

what is the term for a bolus of food after it is undergoing digestion in the stomach

Answer 2

chyme: liquified slurry of food

Question 3

modified tunics

Answer 3

• muscularis has an added internal, oblique layer to allow increased mixing and churning

Question 4

secretory cells

Answer 4

• mucus neck cells
• parietal cells
• chief cells
• enteroendocrine cells

Question 5

mucus neck cells

Answer 5

produce thin, soluble mucus

Question 6

parietal cells

Answer 6

produce HCI and secrete intrinsic factor (required to absorb B12)

Question 7

chief cells

Answer 7

secrete pepsinogen and lipases

Question 8

enteroendocrine cells

Answer 8

secrete chemical messengers into the lamina propria as well as gastrin

Question 9

mucosal barrier

Answer 9

produced to protect the stomach
- thick coating of bicarbonate-rich mucus
- tight junction between epithelial cells
- quickly replacement of damaged mucosal cells by stem cells

Question 10

peptic/gastric ulcers

Answer 10

erosion of the stomach wall - cause gnawing, epigastric pain
- pain appears 1-3 hrs after eating and resolves with eating again
- ulcers are linked to peritonitis and H. pylori

Question 11

propulsion

Answer 11

peristalsis

Question 12

mechanical breakdown

Answer 12

churning

Question 13

digestion

Answer 13

breakdown of proteins by HCI and pepsin (rennin in infants)

Question 14

absorption

Answer 14

only lipid-soluble substances - alcohol and aspirin

Question 15

secretion of intrinsic factor

Answer 15

essential for B12 absorption and maturation of RBCs

Question 16

which branch of the autonomic nervous system increases gastric secretions

Answer 16

• stimulation by vagus nerve
• sympathetic Nervous system decreases secretion

Question 17

gastrin

Answer 17

• stimulate secretion of HCI by the stomach

Question 18

3 phases of the gastric secretions

Answer 18

• cephalic/reflex phase
• gastric phase
• Intestinal phase

Question 19

cephalic/reflex phase

Answer 19

triggered by smell, taste, and sight; act via the vagus nerve

Question 20

gastric phase

Answer 20

triggered by stretch receptors and/or chemical stimuli - partially digested protein, caffeine, rising pH
- activates G cells to secrete gastrin
- gastrin initiates release of HCI
- low pH or firing of the SNS will inhibit gastrin

Question 21

Intestinal phase

Answer 21

partially digested food enters the SI and triggers the release of intestinal gastrin
- distention of the SI and/or presence of acidic, fatty, or hypertonic chyme will inhibit gastric secretions - protects the SI from excess acidity and being overwhelmed

Question 22

enterogastric reflex

Answer 22

short reflexes by the enteric nervous system and long reflexes by the sympathetic and vagus nerves inhibit acid secretion

Question 23

enterogastrones

Answer 23

duodenal enteroendocrine cells release secretin or cholecystokinin to inhibit gastric secretions

Question 24

liver

Answer 24

production of bile

Question 25

bile

Answer 25

fast emulsifier - produces 900mL a day - functions: processes Bloodborne nutrients, stores fat-soluble vitamins, and performs detoxification

Question 26

be prepared to label the lobes of the liver and the two major ligaments

Question 27

lobes of liver

Answer 27

right, left, caudate, and quadrate

Question 28

falciform ligaments

Answer 28

seperates the larger right lobe from the smaller left lobe and suspends the liver from the diaphragm and anterior abdominal wall

Question 29

round ligament/ligamentum teres

Answer 29

remnant of fetal umbilical vein; runs along the free edge of the falciform ligament

Question 30

what is the liver's functional unit

Answer 30

liver lobules

Question 31

hepatocytes

Answer 31

liver cells

Question 32

portal triad

Answer 32

located in each corner of the lobule - hepatic artery - hepatic portal vein - bile duct

Question 33

hepatic artery

Answer 33

supplies oxygen to the liver

Question 34

hepatic portal vein

Answer 34

brings nutrient-rich blood from the intestines

Question 35

bile duct

Answer 35

receives bile from bile canaliculi

Question 36

stellate/hepatic macrophages

Answer 36

exist in liver sinusoids to remove debris and old RBCs

Question 37

bile salts

Answer 37

cholesterol derivatives that function in fat elmusification/absorption

Question 38

bilirubin

Answer 38

yellow pigment formed from heme during the breakdown of RBCs - metabolized by bacteria in the SI to stercobilin which gives feces a brown color

Question 39

what portion of the SI reabsorbs bile salts for recycling

Answer 39

enterohepatic circulation

Question 40

pathway for bile

Answer 40

- right and left hepatic ducts - ducts fuse into common hepatic duct - fuse with cystic duct - common bile duct it combination of cystic duct and common hepatic duct

Question 41

hepatitis

Answer 41

inflammation of liver - viral infection, can be caused by alcohol, drug toxicity, or wild mushrooms - transmitted through food, remainder via blood

Question 42

cirrhosis

Answer 42

progressive, chronic inflammation from hepatitis or alcoholism - liver activity is depressed - liver becomes fatty and fibrous - portal hypertension

Question 43

portal hypertension

Answer 43

flow of blood through the liver is obstructed

Question 44

gall bladder

Answer 44

- thin walled, muscular sac on the inferior surface of the liver - appears green when filled with bile - functions to store and concentrate bile

Question 45

gallstones

Answer 45

obstruct the flow of bile from the gallbladder

Question 46

obstructive jaundice

Answer 46

blockage causes bile salts and pigments to build up in blood

Question 47

exocrine function

Answer 47

production of pancreatic juice - contains enzymes needed to break down all categories of foodstuffs

Question 48

endocrine function

Answer 48

secretion of insulin and glucagon by pancreatic islet cells

Question 49

pancreatic juice

Answer 49

watery, alkaline solution used to neutralize acidic chyme from the stomach - contains electrolytes, primarily HCO3 - digestive enzymes

Question 50

is pancreatic juice acidic or basic

Answer 50

basic

Question 51

digestive enzymes

Answer 51

- proteases - amylase - lipase - nucleases

Question 52

proteases

Answer 52

for proteins; secreted in inactive form to prevent self-digestion

Question 53

amylase

Answer 53

for carbohydrates

Question 54

lipase

Answer 54

for lipids

Question 55

nucleases

Answer 55

for nucleic acids

Question 56

Be prepared to label the main pancreatic duct, the hepatopancreatic ampulla, and the major duodenal papilla. (slide 23)