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BIO 230
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analysis of material before swallowing
B
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initial digestion of food materials by acids
D
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partial digestion of carbohydrates by a salivary enzyme
Cecum
Iliocecal valve-what it receives food from
Vermiform appendix
Function: collects, stores, and begins compaction of arriving materials
Colon
Larger diameter & thinner walls (compared to SI)
Haustra: pouches in walls for distension, sectioning pieces, littlee packets on colon
Taeniae coli: 3 bands of longitudinal smooth muscle, helps with peristalsis movement, you want
peristalsis, slows things down, pulls water out, effects movement of the small muscle
Colon is divided into 4 regions
Move food up and out
Considered normal amount of bowel movements a day: at least once a day, but one bowel movement
every three days is still considered normal
Rectum
Last 6 inches of colon/digestive tract
Temporary storage of fecal matter

Regulation of large intestine
Movements through LI occur slowly
“mass movements” occur a few times/day
• Through transverse colon to end
• Stimulated by distension of stomach & duodenum
Distension of rectal wall triggers conscious urge to defecate
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Metabolic regulation
2
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Bile production
The liver
Metabolic Regulation
• All blood leaving GI goes to hepatic portal system-bringing blood from GI tract to liver
• Regulates circulating CHO, lipids, amino acids
• CHO=Carbohydrates
• Liver regulates excess amounts and deficiencies or toxins, gets drugs out of body once they are done
doing its job, neutralizes it, slightly responsible for deactivating that drug and getting it out of body
• Fat soluble vitamins absorbed here (ADEK)
The liver-Hematologic Regulation
• Blood reservoir, removes damaged RBCs and pathogens-spleen as well,
• Synthesizes plasma proteins (osmotic concentration of blood, transport nutrients, clotting), if liver
doesn’t work you don't have plasma proteins, liver failure leads to all organ failure real quick, two ways
to kill the liver: having a fatty liver and drink alcohol too much
Bile production
• Mostly H2O, also has ions, bilirubin, and bile salts
• Right and left hepatic ducts collect bile from liver, unite at common hepatic duct
• Enters either 1) cystic duct or 2) duodenum
Blood supply to and from liver
Celiac trunk (common hepatic artery)

• Hepatic artery proper
Hepatic vein
Hepatic portal system
Venous blood collects nutrients from small intestine (also from part of large intestine, stomach, and
pancreas)
This blood (oxygen poor and nutrient rich) goes directly to the liver for processing & storage
Blood supply to and from liver
! Celiac trunk (common hepatic artery)
! Hepatic artery proper
! Hepatic vein
Hepatic portal system
! Venous blood collects nutrients from small intestine (also from part of large intestine, stomach, and
pancreas)
! This blood (oxygen poor and nutrient rich) goes directly to the liver for processing & storage
once we get up into liver, functional aspects of liver are the lobules, orientated in the hexagonal
patterns where you have a central vein in the middle, you have a bile such, portal veins, and
blood vessels, functional units where there are plumbing systems going back to the central vein
...
Here the liver removes
many of the materials that were absorbed by the intestine:
•Glucose is removed and converted into glycogen
...

•Monosaccharides (single sugars): glucose, fructose, and galactose
•Excess amino acids are removed and deaminated (take out nitrogen group which will ultimately circulate
out)
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•The residue can then enter the pathways of cellular respiration and be oxidized for energy
...

The liver serves as a gatekeeper between the intestines and the general circulation
...

Furthermore, this homeostatic mechanism works both ways
...

•Body has a big reservoir of amino acids (proteins, because amino acids make up proteins) in the muscle
(actin, myosin, troponin, tropomyosin are all proteins), you can see in extreme cases of starvation you
lose muscle tone
Gallbladder
Function:
Stores & concentrates bile
Location:

Fossa on visceral surface of right lobe of liver
Cystic duct leaving gall bladder unites with common hepatic duct to form the common bile duct entering
duodenum
Ejection of bile from gallbladder
• Chyme (from the stomach) triggers the release of a hormone called cholecystokinin into the
bloodstream
...

• CCK
– Relaxes the hepatopancreatic sphincter
– Contracts the gall bladder-squirting out juice, comes into duodenum
Pancreas-exocrine and endocrine
Exocrine secretes things through a duct and endocrine secretes hormones glucagon and insulin directly
into blood
Sodium carbon solution: helps us to neutralize the highly acidic things that come out
Acinar cells: secrete digestive enzymes (exocrine)
Islets of langerhan cells: endocrine function, hormone
Location:
• Posterior to stomach
• Head of pancreas in “C” of duodenum
• Body extends transversely towards spleen
• Tail blunt/rounded
•
Function:
• Exocrine (primarily) and endocrine gland
• Exocrine function is to produce digestive enzymes
• Delivers enzymes to duodenum through pancreatic duct
Pancreatic duct
Produces
• Digestive enzymes & buffers
• Stimulated to release by:
• Gastrin, CCK, secretin

Blood supply to pancreas
Splenic
Superior mesenteric
Common hepatic arteries
Endocrine and exocrine cells are right next to each other
Watch video on end slide
Bicarbonate: make pancreas juices alkaline in nature, neutralizes chyme



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