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Flashcards in chapter 24 part 2 Deck (62)
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1

chief cells
-definition
-function

-cells of the gastric gland
-secrete pepsinogen

2

pepsinogen
-inactive or active enzyme
-where is it secreted into
-formula

-inactive
-into stomach lumen
-pepsinogen -HCL-> pepsin

3

pepsin
-active or inactive enzyme
-function

-active
-breaks proteins into short fragments

4

G cells
-aka
-function

-pylorus or enteroendocrine cells
-produce gastrin hormone

5

gastrin

increase gastric motility and gastric juice secretion

6

regulation of gastric secretions
-3 phases

1. cephalic
2. gastric
3. intestinal

7

cephalic phase
-4 things
-what does it do

-seeing, tasting, thinking about food, and food in the mouth
-increase gastric juice secretions which is controlled by PNS

8

gastric phase
-definition
-what does this phase do
-3 mechanisms

-food enters the stomach
-increase gastric juice secretion
-1. neural response
2. hormonal response
3. local response

9

neural response of the gastric phase

stretch receptors and chemoreceptors

10

hormonal response of the gastric phase

increase gastrin release

11

local response of the gastric phase

release of histamine in the lamina propria

12

intestinal phase
-definition
-what does this phase do
-2 mechanisms
-what is this controlled by

-food enters the small intestine
-decreases gastric juice production
-neural and hormonal
-the duodenum in response to the arrival of chyme

13

neural response of the intestinal phase

enterogastric reflex

14

hormonal response of the intestinal phase
-contains

1. secretin
2. gastro inhibitory
3. cholecystokinin

15

what do accessory glands do

empty secretions into the small intestine

16

liver
-what does it secrete
-4 things

-bile
-1. L and R hepatic ducts merge to form the common hepatic duct
2. common hepatic duct and cystic duct merge to form the common bile duct
3.pancreatic duct and common bile duct merge at the duodenal ampulla
4. bile and pancreatic juices enter the duodenum at the duodenal papilla

17

bile
-contents
-2 functions
-how much is produced/day

-H2O, Ions, bilirubin and bile salts (derivative of cholesterol)
-1. emulsify fat
2. aid in fat absorption
-1 L

18

emulsify fats

conversion of a large fat blob into smaller fat droplets making it easier for chemical digestion

19

gallbladder
-2 functions

stores bile (40-70ml) and concentrates bile

20

chyme in the duodenum
-what does the duodenum secrete

cholecystokinin

21

cholecystokinin
-2 functions

1. promotes contractions of the gallbladder
2. opens hematopancreatic sphincter

22

pancreas
-2 glands
-composition of pancreatic juice

-endocrine gland and exocrine gland
-water, bicarbonate and phosphate buffers, enzymes

23

endocrine gland of the pancreas
-percent
-contains
-function

-1%
-pancreatic islets
-secretes insulin and glucagon

24

exocrine gland of the pancreas
-percent
-contains

-~99%
-pancreatic acini

25

pancreatic acini
-function
-how much is produced per day

-pancreatic juice
-1L

26

bicarbonate and phosphate buffers are important for

the dilution and buffering of acids in chyme

27

enzymes in the pancreatic juice

1. pancreatic alpha amylase
2. pancreatic lipase
3. nucleases
4. proteolytic enzymes

28

pancreatic alpha amylase
-identical to what
-functions

-salivary amylase
-breaks down starches and produces di and tri saccharrides

29

nucleases
-2 functions

1. breakdown nucleic acids (RNA and DNA)
2. produces nitrogenous bases and simple sugars

30

proteolytic enzymes
-definition
-secreted as inactive or active forms

70% of enzymes produced by pancreas breakdown proteins to form short chain peptides
-inactive proenzymes