small intestine and pancreas

Question 1

What are the small intestine known for?

Answer 1

brk dwn food (chyme) and absorption

Question 2

Chyme is made up of?

Answer 2

Stomach acid, enzyme and food mixture

Question 3

Entrance of the small intestines?

Answer 3

pyloric sphincter

Question 4

3 sections of the small intestines

Answer 4

Duodenum 
-closest to stomach 
-Brunners glands in submucosa
  :produce mucous for protecting small intestine wall from chyme (has acid)
  :incre.=closer to pyloric sphincter in stomach 
Jejunum 
Ileum 
-exit sm. -->lrg intestine

Question 5

Where is plicae circularis located?

Answer 5

small intestine

Question 6

Plicae circularis info.

Answer 6

Incre. SA w/o incre. length=folding 
Has the highest degree of folding 
Degree types of folding 
-1st=Plicae itself (structure)
  :evagination of submucosa w/ mucosa layer of covering 
-2nd=Villus 
  :Evagination of mucosa only 
-3rd=cyrpts of liberkuhn 
  :glands and mucosa invagination 
-4th=microvilli 
  :apical of enterocyte evagination

Question 7

Are there diff. types of villus w/in the sm. intestine

Answer 7

Yes
Duodenum=Leaflike shape broad/not too long
Jejunum=Finger-like long/skinner
Ileum=Shorter villi and still skin

Question 8

Villus-mucosa

Answer 8

Smp. columnar epith.
Enterocyte w/ microvilli
-spec. cell type allowing absorb food macromolec.
Villus=projection of LP containing lacteals
-lacteals are blind lymph vessle/collapse during preparation

Question 9

Enterocytes

Answer 9

Primary function=absorp.
Tall columnar cells w/ microvilli to incre. SA
Release enzyme to brk dwn disacch. and peptide
-dnt brk dwn prot. brkdwn product of prot. brkdwn
Produce lipases and bile acids
-bile acids=produce by bile emulsify lipids for lipase access

Question 10

Enterocytes and junctional complexes regulate movment of H2O across epith.

Answer 10

Help keep H2O influx

-inject. diarrhea=damage junction casuing watery diarrhea

Question 11

Enterocyte and microvilli

Answer 11

Incre. SA w/ actin core
Apical cell portion connect to terminal web
-supports barrier cell function by connecting to IF and cell-cell junction
After prot. brkdwn to peptide/AA by symporter
Brkdwn carb. to monosacch.=specific uptake
Brkdwn lipid FA=cross memb. w/ transprot prot.

Question 12

Small intestine-LP

Answer 12

Loose CT
-Fibroblast
-Plasma cells 
-eosinophils(nt resident but still found there) 
-mast cells 
-MAC 
Surrounds crypts of lieberkuhn 
Small BV 
-support function/take up nut.

Question 13

Difference b/w villus and crupt of lieberkuhn

Answer 13

Growth
-villus=above surface
-crypts=below surface
Enterocyte w/ goblets=both
Paneth cells=crypt only
-Exocrine cells secrete to crypt lumen and has apical secreting granules
-protective enzymes
:lysozyme=attack bact. cell wall
:phospholipase A2=attack bact. cell memb.
:defins r peptide=bind/brkdwn memb. and cell wall of micro-organism
Enteroendocrine=crypt only
-endocrine secrete into tissue @times not have granules
-nuclei r gen centered
-clear cytoplasm w/ basal granules

Question 14

Submucosa-Duodenum

Answer 14

Dense CT

Has bruners gland=mucous to protect lining from chyme

Question 15

Submucosa-Jejunum

Answer 15

Dense CT

Question 16

Submucosa-Ileum

Answer 16

Dense CT 
Payers patches 
-M cell assoc. w/ enterocyte 
-lymph vessels under 
-cells w/o microvilli and smp. cuboidal

Question 17

Muscularis externa-small GIT

Answer 17

2 layers of sm. muscle=inner circ. and outter long.
-segmentation=2 sides will contract while middle relax
:helps w/ mixing food
-Peristalis=1 area contract as dwn strm relax to push dwn the anus
2 N. plexus=meisners(submucosa) and myentric plexu (b/w 2 muscle layers)
-apart of the intrinsic enteric N. controling motor/sensory acivities in digestive tract

Question 18

Adventia and serosa-small GIT

Answer 18

Both of dense CT
Smp. sq. epith. (mesothelium)=only serosa
Adipose/lrg BV and N= adventitia

Question 19

2 types of glands in pancreas

Answer 19

Endocrine and exocrine

Question 20

Pancreas-endocrine

Answer 20

Action=secrete metobolic horm.
Highly vasculized=Y to support Nut. in and waste out
Location=w/in pancreatic iselt(islet of langerhon)
-3 cells that cn be distinguish by HE (only seen in IF)
:alpha=glucagon to incre. blood gluc.
:beta=insulin to decre. blood gluc.
:delta=somatostatin and gastin
-inhib. alpha and beta
-affect parietal cell to produce HCl and pit. gland

Question 21

Which pancreatic endocrine cells controlled by blood gluc. ?

Answer 21

alpha and beta

Question 22

Pancreas-exocrine

Answer 22

Action=produce digestive enzyme into duodenum
Highly vasc.=NO
Location=around pancreatic islet

Question 23

deeper exocrine explanation

Answer 23

Secretory enzyme/granules=pancreatic acinar cells
-acinar cell
:acini shape of gland w/
Contain granule=lipid-based vesicles filled w/ zymogen
-pro digestive enzyme
Release productive apical into interlobular duct (lined centroacinar cells) –>intralobular duct
-controlled by CCK=secretin (not control by granule)

Question 24

Pancreas-exocrine ducts

Answer 24

Centroacinar cell start to line first 
Intercalated duct line w/ sq. epith. 
-connected to intralob.-->main duct-->dudodenum 
-nt striated 
-most of the 1L fluid/day secretion 
  :a little fluid from acinus 
-most ion 
  :rich in Na and Bicarb(correct pH for enzymes from chyme)
-Nutrilze chyme

Question 25

pancreatic enzymes

Answer 25

Bicarb.=not by acinar cells
Porteases=chymo, trypsin, elastase, protease E, Kallikrein 
Alpha amylase-brk dwn carb. 
Lipases 
DNases and RNases

Question 26

Trypsins

Answer 26

activated in small intestine and cleave other zymogens to activate them

Question 27

pancreatic enzyme travel

Answer 27

Main pancreatic duct (of wrsung)
Hepatopancreatic ampulla (of vater)
-w/ bile duct 
Major duodenal papilla 
Spincter of hepatopancreatic ampulla (of oddi)