Glands and Accessory Organs

Question 1

What is the function of the saliva? What are the 3 glands?

Answer 1

Facilitate taste, swallowing, and initiate digestion

Contains proteins, enzymes, ions, mucins, etc.

3 major salivary glands are the parotid, submandibular, and sublingual

Question 2

What does the parotid gland secrete?

Answer 2

Purely serous

Question 3

What does the submandibular gland secrete?

Answer 3

Mainly serous with some mucous

Question 4

What does the sublingual gland secrete?

Answer 4

Mainly mucous and some serous

Question 5

What is the structure of the exocrine pancreas?

Answer 5

Secretes digestive enzymes - primarily serous

Secretory cells arranged into pancreatic acini - acinar cells are pyramidal and contain zymogen granules (inactive digestive enzymes)

Intercalated ducts - carry products of acini to larger interlobar ducts within pancreas. Centroacinar cells project into center of acini and ductal cells secrete water and bicarbonate

Question 6

What covers the liver?

Answer 6

Thin yet strong connective tissue called Glisson’s capsule

Covered by liver mesothelium which is simple squamous

Question 7

What are hepatic lobules?

Answer 7

Contain hepatocytes that have sinusoids or spaces between hepatocytes

Central vein in center of hepatic lobules

Question 8

What is the hepatic lobule structure and what does it emphasize?

Answer 8

Traces flow of blood through the liver

Hexagonal plates of hepatocytes and sinusoids

Center contains central vein and corners contain portal canals

Question 9

What is the blood supply in the hepatic lobule?

Answer 9

Mostly from portal vein and then some from hepatic artery

Question 10

What is the path of blood through the liver?

Answer 10

Blood from portal vein and hepatic artery anastomose to form sinusoids

Blood flows through sinusoids where it is processes by hepatocytes

Processed blood flows into central vein

Flows into hepatic vein back to IVC

Question 11

What is the portal lobule structure and what does it emphasize?

Answer 11

Emphasizes bile production and secretion

Triangular

Bile duct at center of lobule and central veins at corners

Question 12

What is the path of bile production?

Answer 12

Bile produced by hepatocytes into bile canaliculi

Flow towards bile duct in portal canal

Opposite direction of blood flow

Question 13

What is the hepatic acinus structure and what does it emphasize?

Answer 13

Describes blood perfusion and metabolic activity

Quadrangular

Long axis between central veins and short axis between portal canals

Zone 1 - closes to portal canal and hepatocytes are exposed to more oxygen, nutrients, toxins. Less CO2 and metabolic waste. Cells first to regenerate and last to die

Zone 2 - farthest from portal canals, hepatocytes exposed to blood with less oxygen, nutrients, and toxins. More CO2 and waste. First to show damage and die

Question 14

What is the portal canal and what does it contain?

Answer 14

Region at corners of classical hepatic lobule

Loose CT continuous with Glisson’s capsule

Lymphatic vessels

Portal triad - portal vein, bile duct (simple cuboidal), and hepatic artery

Periportal space - Space of Mall. space between hepatocytes and portal canal

Question 15

What are the sinusoids of the liver? What do they contain?

Answer 15

Formed by anastomosis of the hepatic artery and portal vein in portal canal

Sinusoidal epithelium - discontinuous simple squamous epithelium that lines sinusoids

Kupffer cell - hepatic macrophages that form part of sinusoidal lining

Perisinusoidal space - site of exchange between blood plasma and hepatocytes, microvilli of hepatocytes project in for increased exchange

Stellate cell - store vitamin A and lipids

Question 16

What are the functions of hepatocytes?

Answer 16

Bile manufacture - water, bile salts, bilirubin, fats

Lipid metabolism and storage

Carbohydrate metabolism and storage

Protein metabolism

Vitamin storage - A, K, D, B12

Detoxification of drugs

Degradation of hormones

Immune response - kupffer cells

Question 17

What is jaundice and its two types?

Answer 17

Elevated levels of unconjugated bilirubin in the bloodstream

Obstructive jaundice - decrease in ability of hepatocytes to conjugate bilirubin, blockage of bile ducts, so same amount of bilirubin but cannot be excreted with bile

Hemolytic jaundice - increased breakdown of red blood cells leads to increased level of bilirubin

Question 18

What is the biliary tract and what does it contain?

Answer 18

Helps with main exocrine secretion of liver

Bile flows toward bile ducts in portal canals

Bile canaliculi - spaces between hepatocytes bounded by tight junctions

Canals of Hering - simple cuboidal epitheloum and lined with cholangiocytes

Intrahepatic bile ductules

Interlobular bile ducts - within portal canal

Hepatic ducts - simple columnar epithelium

Question 19

What is the path of bile through the biliary tract?

Answer 19

Bile produced by hepatocytes

Bile canaliculi

Canal of Hering (simple cuboidal, cholangiocytes)

Intrahepatic bile ductules (simple cuboidal, cholangiocytes)

Interlobular bile ducts (simple cuboidal, cholangiocytes)

Hepatic ducts (simple columnar)

Gallbladder (simple columnar)

Question 20

What is the function of the gallbladder?

Answer 20

Storage, concentration, and release of bile

Question 21

What layers does the gallbladder contain?

Answer 21

Mucosa

Muscularis externa - disorganized

Adventitia and serosa

Lacks muscularis muscosae and submucosa

Question 22

What is the structure of the mucosa of the gallbladder?

Answer 22

Simple columnar epithelium with microvilli present

Lamina propria

Muscularis mucosae absent

Question 23

Where is adventitia and serosa present in the gallbladder?

Answer 23

Serosa on peritoneal surface

Adventitia on hepatic surface

Question 24

What are gallstones?

Answer 24

Typically made of cholesterol or calcium bilirubinate

Asymptomatic unless they become lodged in cystic or common hepatic duct