Download Accessory Organs to the Digestive Tract

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Teeth – mechanical digestion through mastication
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Salivary glands – parotid, submandibular, sublingual
◦ Secrete saliva, a bicarbonate rich juice
◦ chemical digestion via secretions of enzymes
 Salivary amylase begins starch digestion
◦ Saliva also contains lysozyme and antibodies to inhibit
bacteria
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Pancreas
Liver
Gallbladder
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Mouth (oral cavity)
Tongue
Parotid gland
Sublingual gland
Submandibular
gland
Salivary glands
Pharynx
Esophagus
Stomach
Pancreas
Liver
Gallbladder
Small
intestine
Anus
Duodenum
Jejunum
Ileum
Transverse colon
Descending colon
Ascending colon
Cecum
Sigmoid colon
Rectum
Appendix
Anal canal
Large intestine
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Produces digestive enzymes that break down
all categories of food
◦ releases into the duodenum via the
hepatopancreatic ampulla
◦ Alkaline (bicarbonate) fluid with these enzymes
neutralizes the acidic chyme
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Produces hormones: (negative feedback
loops)
◦ Insulin – reduces blood glucose
◦ Glucagon – raises blood glucose
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largest gland in the body; consists of four lobes
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can regenerate if part is damaged/removed
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suspended from the diaphragm and abdominal
wall by the falciform ligament
Connected to the gallbladder via the common
hepatic duct
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the body’s key metabolic organ
After the GI tract, blood travels to liver via the hepatic
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Roles in digestion:
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portal circulation
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Manufactures bile and blood clotting proteins
Detoxifies drugs and alcohol
Degrades hormones
Produces cholesterol:
 Low Density Lipoproteins: transport cholesterol/lipids to the cells; large
amounts circulating can build up in vessel lumen (BAD GUYS)
 High Density Lipoproetins: transport cholesterol from the cells to the
liver for disposal in bile (GOOD GUYS)
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The liver manages blood glucose levels through:
◦ Glycogenesis: “Building glycogen”
◦ Glucose is removed from the blood (via insulin)
◦ Converted to glycogen and stored in the liver
◦ Glycogenolysis: “Splitting glycogen”
◦ Glucose is released into the blood (via glucagon)
◦ Glycogen is “split” and put back into blood
◦ Gluconeogenesis: “Building glycogen from other sources”
◦ The Liver can make glucose using fats and amino acids
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produced by the liver
a yellow-green, watery solution containing:
◦ Bile salts and bile pigments (mostly bilirubin from
the breakdown of hemoglobin)
◦ Cholesterol, phospholipids, and electrolytes
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leaves the liver via the common hepatic duct
◦ enters duodenum through the bile duct
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Function: emulsify fats
◦ Chemically breaks down large fat globules
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Sac found in shallow fossa of liver
When no digestion is occurring:
◦ bile backs up the cystic duct for storage in the
gallbladder
 Water is removed at this time to concentrate it
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Gallstones
◦ crystallized cholesterol that can cause blockages
 Result from removal of too much water
 Prolonged storage in gallbladder
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Right and left
hepatic ducts
from liver
Cystic duct
Common hepatic duct
Bile duct and sphincter
Accessory pancreatic duct
Pancreas
Gallbladder
Jejunum
Duodenal
papilla
Hepatopancreatic
ampulla and sphincter
Main pancreatic duct and sphincter
Duodenum