Histology of Accessory Organs

Question 1

What is the flow of saliva?

Answer 1

acinus –> intercalated duct (low cuboidal epi) –> straited duct (simple cuboidal to columnar epi) –> excretory duct (simple cuboidal to pseudostrat columnar or stratified cuboidal)

Question 2

What does mucous acini produce?

Answer 2

thick glycoprotein rich product

Question 3

What does serous acini produce?

Answer 3

water based product

Question 4

What is the structure of mucoserous acini?

Answer 4

core of mucous cells surrounded by serous Demilune

Question 5

Where are myoepithelial cells found? What do they assist in?

Answer 5

located between epithelial cells and basal lamina

moving secretory products toward the excretory duct

Question 6

What kind of acini does the parotid gland have?

Answer 6

serous

Question 7

What are the cellular features of the parotid gland?

Answer 7

Pyramidal cells with basally located nucleus, prominent RER in basal region, secretory granules visible in apical region

Question 8

What are the features of the sublingual gland?

Answer 8

Branched tubule-alveolar gland with serous and mucous cells (but predominatly mucous), lacks defined capsule but is divided by CT into small lobes, intercalated and striated ducts are poorly developed

Question 9

What kind of cells does the submandibular gland have?

Answer 9

Mucous cell have acini that are capped by serous demilunes

Serous secretions controlled by myoepithelial cells

Question 10

What is the job of the exocrine component of the pancreas? What is its functional unit?

Answer 10

synthesizes/secretes enzymes essential for digestion in intestine

Serous acinus which contrains acinar cells

Question 11

Where are the intercalated ducts of the exocrine pancreas? What do they secrete?

Answer 11

within acinus cetroacinar cells, continuous with low cuboidal of intercalated

HCO3-, Na+ and H20

Question 12

What is the role of pancreatic acinar cells?

Answer 12

Have apical domain of zymogen granules which have pancreatic proenzymes, adjust levels based on diet (high carb then amylase, high protein then proteases)

Question 13

What is the role of the endocrine component of the pancreas?

Answer 13

synthesizes/secretes hormones (insulin and glucagon) into blood –> regulation of glucose, lipid, and protein metabolism

Question 14

What do the islets cells of the pancreas produce?

Answer 14

alpha= glucagon
beta= insulin
gamma= somatostain
pp cells= pancreatic polypeptide

Question 15

What encloses the liver?

Answer 15

thin CT capsule line with mesothelium of visceral peritoneum lacking where directly adheres to diaphragm

Question 16

What is the job of hepatocytes?

Answer 16

Secrete bile mixture of H2O bile salts and pigments phospholipids

Drains into bile canaliculus, canal lined with cholangiocytes located btwn adjacent hepatocytes, canaliculi join to eventually contribute to biliary tree

Question 17

What is the function of bile?

Answer 17

fat absorption, excretion, cholesterol, bilirubin, iron, copper

Question 18

What are the functional units of the liver?

Answer 18

hepatic lobule= histo
portal= bile and exocrine function
liver acinus= blood flow and O2 content

Question 19

What are hepatic lobules?

Answer 19

Organization of liver parenchyma, form irregular plates radiating from central vein which are supported by a stroma of reticular fibers, plates separated by sinusoids (discontinuous)

Question 20

Does blood and bile flow in the same direction?

Answer 20

NO opposite

Question 21

What do the peripheral angles of hepatic lobules contain?

Answer 21

portal triad in fibrous CT= venule branch of portal vein rich in nutrients low in O2, arterioles from hepatic a. which supply O2, and bile

Question 22

What are hepatic sinusoids?

Answer 22

anastomosing capillaries that perfuse hepatocytes with portal and arterial blood

Question 23

What are Kupffer cells?

Answer 23

stellate macrophages within endothelium of sinusoids, larger than endo cells, detect and phagocytose effete erythrocytes, distinguish hepatic sinusoids

Question 24

What are stellate macrophages?

Answer 24

small lipid droplets that store Vitamin A and other fat soluble

Question 25

Where is the perisinusodial space of Disse?

Answer 25

between hepatocytes and sinusoidal endothelium (discontinuous cap), creates a potential space for exchange of materials between blood and hepatocytes

Question 26

What is the role of the perisinusodial space of Disse?

Answer 26

Facilitates uptake/release of nutrients, proteins, and potential toxins

Microvilli project into space, plasma fills and bathes microvilli, increase SA

Question 27

What are bile canaliculi?

Answer 27

anastomosing network of channels formed by hepatocyte plates and end near portal triads

Question 28

What eventually becomes the R and L hepatic ducts?

Answer 28

Canaliculi –> canals of Hering (composed of cuboidal epithelial cells, cholangiocytes) –> bile ductules –> merge and enlarge –> r and l hepatic ducts

Question 29

What is a portal lobule?

Answer 29

Central axis s bile duct, outlines bile drainage pathway from adjacent lobules in same bile duct, draw imaginary lines btwn 3 central veins triangle

Question 30

What is a liver acinus?

Answer 30

Diamond shape and occupies parts of adjacent classic lobules, hepatocytes arranged in concentric zones around short axis, based on O2 gradient along sinusoids of adjacent lobules

Question 31

What are Rokitansky-Aschoff sinuses?

Answer 31

deep diverticula of mucosa that extend through muscularis externa, develop as result of hyperplasia and herniation of epithelial cells through muscularis externa, bacteria can accumulate –> chronic inflamm and risk of gallstones

Question 32

Where does the gallbladder have adventitia? Serosa?

Answer 32

Against the liver

Exposed to peritoneal

Question 33

What is the job of the gallbladder?

Answer 33

stores and concentrates bile, release it into duodenum after a meal

Question 34

What kind of mucosa is in the gallbladder?

Answer 34

Highly folded with simple columnar epithelium overlying lamina propria