Phy & Pharm Intestines

Front 1

where are the I cells and what hormone do they secrete

Back 1

in duodenum & jejunum

Cholecystokinin CCK

Front 2

where are the S cells and what hormone do they secrete

Back 2

Duodenum

secretin

Front 3

where are the M cells and what hormone do they secrete

Back 3

duodenum & jejunum

motilin

Front 4

where are the K cells and what hormone do they secrete

Back 4

duodenum & jejunum

glucose-dependent (glucagon-like) insulinotrophic peptide (GIP)

Front 5

where are the L cells and what hormone do they secrete

Back 5

small and large intestine

glucagon-like peptide 1 (GIP1)

Front 6

the succus entericus are interstinal juices- what does it contain

Back 6

mucus
aqueous salts
(no dig enzymes)

Front 7

how does Cl- leave the enterocyte at the apical membrane

Back 7

CFTR chloride channel

Front 8

what initiates the BER in the duodenum

Back 8

distention

Front 9

what initiates SEGMENTATION in empty ileum

Back 9

gastrin from stomach (pyloric gland area- antrum)

Front 10

whats the migrating motor complex (MMC)
when does it occur

what is it triggered/ inhibited by?

Back 10

activated peristalsis BETWEEN meals
stong wave whole length intestine
clears debriis/ mucus

INHIB: vagal stim, gastrin, CCK
TRIG: motilin

Front 11

EXOcrine pancreas:
- anatomy
- secretions
- destination of secretions

Back 11

EXO= ducts
ACINI cells surround DUCT cells
DIG enzymes & aqueus NaHCO3 --> duodenum (pancreatic juices)

Front 12

ENDOcrine pancreas:
- anatomy
- secretions
- destination secretions

Back 12

ENDOcrine = end-no ducts, direct to BLOOD
ISLETS of langerhands
INSULIN & GLUCAGON

Front 13

composition of pancreatic juices from acinar cells

Back 13

PROTEASES (inactive):
- trypsinogen
- shymotrypsinogen
- procarboxypeptidase

pancreatic AMYLASE

pancreatic LIPASE

Front 14

which enzyme in the duodenum activates the first protease in the autocatalysis chain

which is the first protease to be activated

Back 14

enterokinase activates trypsinogen

Front 15

pancreatic acinar cells secrete dig enzymes and aqueous NaHCO3:
- what stimulates which cells to secrete which hormone which stimulates acinar cells to secrete NaHCO3

Back 15

duodenal ACID → S cells duodenum → secretin → acinar secrete aqueous NaHCO3

Front 16

pancreatic acinar cells secrete dig enzymes and aqueous dig enzymes:
- what stimulates which cells to secrete which hormone which stimulates acinar cells to secrete dig enzymes

Back 16

FAT & PROTEIN in duodenum → I cells duodenum & jejunum → CCK → acinar secrete dig enzymes

Front 17

where is bile produces, stored and concentrated

what stimulates release

which ducts involved

role

Back 17

LIVER produces
GB stores and concs

FAT & distension stimulates GB contraction → cystic duct & hepatic ducts → CBD → sphincter of Oddi

dig & absorption of FATs

Front 18

secretin from S cells of duodenum stimulate pancreatic acinar secretion of NaHCO3.

what other 2 roles does SECRETIN play in INTESTINAL phase

Back 18

↓ gastric secretion/ emptying
increase bile secretion (into duodenum)

Front 19

CCK from I cells of duodenum & jejunum stimulate pancreatic acinr dig enzyme secretion.

What other 2 roles does CCK have in INTESTINAL phase?

Back 19

↓ gastric secretion/ emptying
GB contraction (&sphincter of Oddi relaxation)

Front 20

5 types/ components of lipids

Back 20

triACYLglycerols ~90%
FFAs
cholesterol
lipid vitamins
phospholipids

Front 21

3 types of ingested carbs

Back 21

starch
glycogen
disaccharides

Front 22

what does salivary a-amylase do

Back 22

break starch/ glycogen --> maltose/ moltotriose/ isomaltose

Front 23

which 6 intestinal enzymes further breakdown carbohydrates

Back 23

pancreatic amylase
a-glucosidase
isomaltase
maltase
sucrase
lactase

Front 24

what substrate & prod assoc with sucrase

Back 24

sucrose--> fructose & glucose

Front 25

what substrate & prod assoc with lactase

Back 25

lactose --> GALACtose & glucose

Front 26

what are the 3 final products of carb dig

Back 26

glucose
fructose
galactose

Front 27

how are the 3 final prod of carb dig transported into/out of enterocytes

Back 27

glucose & galactose--> secondary active transport SGLT1 --> GLUT2
fructose --> facilitated DIFFUSION --> GLUT 5

Front 28

which protein facilitates diffusion of fructose through the enterocyte

Back 28

GLUT5

Front 29

which secondary active transporters transport glucose & galactose through the apical & basal side of the enterocyte

Back 29

apical- SGLT1
basal- GLUT2

Front 30

in the transport of glucose & galactose across the enterocyte (via secondary active transport- SLGT1 & GLUT2) which other enterocyte membrane protein is important in maintaining a Na+ electrochemical gradient to provide means of energy for which transporter

Back 30

Na/K ATPase on basal side of enterocyte maintains Na gradient for SGLT1 on apical side

Front 31

which carbodydrate transporter in the enterocyte is exploited in treating diarrhoea

Back 31

GLUT2 (basal side for glucose & galactose)

Front 32

what's the difference between endo & exo peptidases

Back 32

endo: break peptide bonds WITHIN peptide chain

exo: break TERMINAL peptide bonds

Front 33

where does protein digestion begin via which enzyme

is it an endo- or exo-peptidase

Back 33

stomach- PEPSIN
ENDOpeptidase

Front 34

which endo- and exo-peptidases digest protein in the duodenum

Back 34

ENDO: pancreatic enzymes (trypsin, chymotrypsin, carboxypeptidase)

EXO: brush border enzymes

Front 35

3 major final products of protein dig

Back 35

amino acids
dipeptides
tripeptides
(few oligopeptides)

Front 36

how are amino acids transported across the enterocyte (which transport mechanism)

Back 36

(hydrophobic amino acids: PASSIVE DIFFUSION)
mainly ACTIVE transport:
- brush border (7 mechanisms): 5Na+-dep, 2Na+-INdep
- basal side: Na+-INdep

Front 37

in transport of amino acids at the apical side of the enterocyte, what mechanisms are used

Back 37

7 different ACTIVE FACILITATED transport mechanisms by brush border proteins:
- 5 Na-dependent
- 2 Na-INdependent

Front 38

what mechanism of transport do amino acids use at the basal side of enterocytes

Back 38

Na-INdependent FACILITATED transport

Front 39

how are di- and tri-peptides transported across the apical side of the enterocyte

what happens within the enterocyte

Back 39

H+-dependent CO-transported

HYDROLYSIS--> amino acids

Front 40

what mechanism of transport on the basal side of teh enterocyte do di and tri-peptides use

Back 40

hydrolysed within enterocyte --> amino acids so use the amino acid mechanism of Na-INdep facilitated diffusion

Front 41

why does digestion & absorption of FATS require bile salts

Back 41

fats are insoluble / hydrophobic, form lipid droplets with low SA

Front 42

which enzyme hydrolyses fats in stomach

products

Back 42

gastric lipase

diglycerides + FFAs (stimulates CCK release from I cells of duodenum & jejunum)

Front 43

triglyceride hydrolysis in stomach produces FFAs...what cells does this stimulate & what's the effect
- how does thie furhter aid dig fats in duodenum

Back 43

stimulates I cells in duodenum & jejunum --> CCK --> stimulates pancreatic acinar cells --> dig enzymes incl pancreatic lipase

Front 44

what 3 components aid fat dig in duodenum

Back 44

pancreatic lipase
bile salts
HCO3 optimises pH

Front 45

which hormone stimulates GB contraction

which cells produce this hormone

where are they located

what is the hormone release stimulated by

Back 45

CCK released from I cells of duodenum & jejunum

simulated by FAT & PROTEIN

Front 46

hwo do bile salts bind lipid droplets

Back 46

amphipathic molecules - solubilse / emulsify

increase SA for pancreatic lipase

Front 47

where & when is COLIPASE secreted

what is its role

Back 47

secreted with pancreatic LIPASE
binds to bile salts & lipase
allows access

Front 48

priduces of triglyceride breakdown by pancreatic lipase

Back 48

2-monoglycerids + 2x FFA

Front 49

5 final prod's of lipis dig

Back 49

monoglycerides
FFAs
bile salts
phospholipids
cholesterol

Front 50

where are the 5 final products of lipid breakdown all stored and released from

Back 50

micelles

Front 51

how do FFAs & monoglycerides enter enterocytes

Back 51

PASSIVE diffusion

Front 52

how do SHORT & MEDIUM chain FAs exit basal side of enterocytes

where's there destination of absorbtion

Back 52

PASSIVE diffusion

cpillary --> blood

Front 53

how do LONG chain FAs & MONOGLYCERIDES exit the basal side of enterocytes

where is their destination of absorption

Back 53

resynthesised to TRIGLYCERIDES --> incorperated into CHYLOMICRONS
EXOCYTOSED --> lacteals --> lymph

Front 54

how are chylomicrons synthesised in the enterocyte:
- substrates
- loc
- stages
- exit

Back 54

- from MONOGLYCERIDES & LONG FFA's
- SER triglyceride resynthesis + choolesteryl esters + phospholipids + apoB48 --> EXOcytosis

Front 55

how are chylomicrons metabolised
- loc
- enzyme
- prod's
- how taken up by binding to what

Back 55

muscle & adipose
LPL at endothelial cells --> FFAs + glycerol
bind to ALBUMEN --> taken up by tissues

Front 56

how are FFAs & glycerol (metabolised by LPL from chylomicrons in muscle & adipose) taken up by tissues

Back 56

initially bound to ALBUMEN

Front 57

a metabolised chylomicron, depleted of it's triglycerides, becomes a CHYLOMIRON REMNANT:
- what is it left enriched with
- where is it metabolised
- what are the fates of cholesterol

Back 57

Chylomicron REMNENT enriched with cholesteryl esters & phospholipids
endocytosed by LIVER
cholesterol:
- stored
- secreted unaltered in bile
- oxidised to bile SALTS

Front 58

how does EZETIMIBE prevent cholesterol absorption

what drug is it used in conjunction with

Back 58

blocks NPC1L1 at apical side of enterocyte
used in conjuction with STATINS

Front 59

what 2 substances regulate ACTIVE absorption of Ca2+

Back 59

vitamin D3
parathyroid hormone (increases vit D3)

Front 60

how does vit D3 influence ACTIVE absorption of Ca2+

Back 60

increases expression of Ca channels and Ca ATPase

Front 61

what vitamin is requried for iron oxidation (dig for absorption)

Back 61

vit C

Front 62

which transporter transports oxidised iron into enterocytes

Back 62

DMT1

Front 63

oxidised iron is either stored:- where and in what form

or exported from enterocyte:- by what transporter

Back 63

stored: as FERRATIN in enterocyte

exported: by FERRAPORTIN

Front 64

FERRAPORTIN exports iron from enterocytes, what negatively regulates this proecss (MAJOR)

when

Back 64

HEPCINDIN when iron concs high
(from liver)

Front 65

4 fat-soluble vitamins
how are they absorbed

Back 65

A,D,E,K
micelles/ chylomicrons
lymphatics

Front 66

3 water-soluble vitamins
how are they absorbed

Back 66

B (not B12!), V, H

similar process to amino acide at apical side (Na-indep / dep co-transporters)

Front 67

Vit B12 is only present in minute amounts in diet. requires complex absorption. important stages/ molecules / locations for B12 absorption

Back 67

HAPTOCORIN (secreted in salive, binds in stomach)
stomach ACID (releases B12)
parietal cells --> intrinsic factor
pancreatic proteases release HAPTOCORIN (s.int)
B12 binds with INTRINSIC FACTOR (s.int)
TERMINAL ILEUM (endocytosis)