Term
| What is the largest gland in the body? |
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Definition
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Term
| how many functions does the liver perform? includes: |
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Definition
over 500
Processing and storage of nutrients
Secretion of most plasma proteins
Blood coagulation proteins
Detoxify/metabolize many toxic substances
Bilirubin: breakdown product of hemoglobin; most eliminated from body in feces (enter duodenum in bile |
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Term
| Digestive function of the liver? What aids in it? |
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Definition
bile production
-Bile salts: derivatives of cholesterol; aid in fat digestion |
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Term
Gross anatomy of the liver:
lobes
surfaces
porta hepatis |
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Definition
Two major lobes – right and left
Two additional lobes – smaller; quadrate and caudate
Now considered to be part of left lobe
Superior surface – diaphragmatic surface; visceral peritoneum continuous with diaphragm (except in bare area)
Posterior/inferior surface = visceral surface
Porta hepatis (“gateway to liver”) – where most blood vessels, nerves, and hepatic ducts (bile) enter and leave liver |
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Term
| What is the hepatic portal system? |
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Definition
A specialized part of the vascular circuit
Portal system = two different capillary beds in series
Picks up digested nutrients
Delivers nutrients to the liver for processing
Also picks up potentially toxic substances that have been ingested and delivers to liver |
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Term
Veins of the hepatic portal system:
splenic
superior mesenteric
inferior mesenteric |
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Definition
Splenic Vein
Any microbes escaping the spleen travel to liver to be destroyed
Superior mesenteric vein
Drains entire small intestine; part of colon
Inferior mesenteric vein
Drains distal colon, including rectum
Converges with splenic vein |
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Term
| Which veins converge to form hepatic portal vein? Gastric veins converge before? |
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Definition
| Splenic and superior mesenteric veins converge to form hepatic portal vein gastric veins converge before entering liver |
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Term
Histology of liver:
what type of gland0
What are hepatocytes?
What are the basic units? |
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Definition
Unusual gland (no typical secretory units)
Hepatocytes = liver cells
Basic units are hepatic lobules |
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Term
| What are hepatic lobules consisting of? |
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Definition
Hexagonal-shaped collections of hepatocytes
Hepatocytes are arranged into plates/sheets
Central vein at the center of each lobule
Portal triad present at each of the sides; each triad consists of:
Segment of hepatic portal veinule
Segment of arteriole from hepatic artery
Segment of bile duct |
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Term
| what is the blood flow through the hepatic lobule? |
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Definition
Blood sinusoids are present between the sheets/plates of hepatocytes
Blood drains from portal triads (periphery of lobule) through sinusoids toward central vein
Mixing of hepatic portal blood and arterial blood
Central veins converge on hepatic veins which drain into inferior vena cava |
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Term
describe hepatocytes?
How much CT in liver? |
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Definition
Hepatocytes: cuboidal with a central nucleus
Little connective tissue |
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Term
| What is the extracellular space in liver between plates of hepatocytes and sinusoids? What does it contain? |
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Definition
Extracellular space between plates of hepatocytes and sinusoids = Space of Disse’
Contains dendritic cells |
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Term
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Definition
specialized
macrophages; resident
phagocytic cells in the
sinusoids |
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Term
| What is the bile canaliculi? |
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Definition
(“small bile canals”) run in between hepatocytes; drain bile toward bile ducts at the triads
Bile canaliculi formed from fused (tight junctions) plasma membranes of adjacent hepatocytes
Bile travels from center of lobule toward periphery |
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Term
| What does the gall bladder do? where is it? |
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Definition
Stores and concentrates bile
Expels bile into duodenum
Bile contains bile salts that emulsify fats; prevent formation of large fat droplets
Digestive enzymes from pancreas are able to breakdown small fat droplets faster
Bile salts do not directly chemically digest fats
Sits in shallow groove along visceral surface of liver (right lobe) |
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Term
| Gall bladder is a -- sac, what type of epithelium, and what does it absorb to do what? |
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Definition
Muscular sac
Simple columnar epithelium
Absorbs water and ions to concentrate bile |
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Term
| Flow of bile around gallbladder? |
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Definition
Two-way flow of bile
Bile enters: hepatic ducts -> cystic duct -> gallbladder
Bile leaves: cystic duct -> common bile duct -> duodenum |
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Term
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Definition
contractions of muscularis externa bile out
of gallbladder |
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Term
| exocrine function of the pancreas? |
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Definition
Acinar cells make, store, and secrete pancreatic enzymes
Enzymes chemically digest carbohydrates, fats, and lipids |
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Term
| endocrin function of the pancreas? |
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Definition
produces insulin and glucagon
Regulates blood sugar |
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Term
| describe exocrine pancreas? |
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Definition
Numerous compound acinar glands
Acini contain secretory cells
Zymogen granules: stored enzymes
Enzymes activated inside duodenum
Small ducts leave each acinus and converge on main pancreatic duct
Main pancreatic duct enters duodenum |
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Term
| describe endocrine pancreas? |
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Definition
Endocrine cells located in small clusters scattered throughout pancreas
Islets of Langerhans
Islets contain four cell types
Two are involved with blood glucose regulation
a (alpha) cells: secrete glucagon – increase blood glucose levels
b (beta) cells: secrete insulin – decrease blood glucose levels
Numerous capillaries surround cords of cells |
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