Histology of accessory organs

Question 1

The liver is a solid organ composed of tightly packed pink staining plates called

Answer 1

Hepatocytes.

Question 2

collagenous capsule into the outer surface of liver -coverd by ?

Answer 2

mesothelial layer from the peritoneum

Question 3

spaces that lie between hepatocytes
and are vascular seen, as pale-stained spaces between plates of liver cells.

Answer 3

Sinusoids

Question 4

sinusoids form low resistance system of ……….

Answer 4

very channels allowing blood to be in contact with hepatocytes.

Question 5

which tissue is found most in the portal tract, which contains what ?

Answer 5

collagenous tissue and contains main blood vessels running into liver.

Question 6

a structure running in the portal tracts is

Answer 6

bile ducts.

Question 7

Terminal hepatic venules .

Answer 7

are also called centrilobar venules which drain the liver and are tributaries of hepatic veins which shunt blood to the inferior vena cava.

Question 8

hepatocytes

Answer 8

are large polyhedral cells with round nuclei, peripherally dispersed chromatin and prominent nucleoli. binucleate cells are common.

Cytoplasm has variable appearance

Brown granules of wear-and-tear pigment lipofuscin

Question 9

what cells line the sinusoid ?

Answer 9

lined by flat endothelial cells which are distinguished by the flattened condensed nuclei.

Question 10

small-diameter thick walled vessesls

Answer 10

are terminal branches of hepatic arteries.

Question 11

Bile canaliculi

Answer 11

drains into bile-collecting ducts
is lined by simple cuboidal or columnar epithelium, and drains into bile ductules.

Question 12

ductules emerge forming what structure and that structure drains into what?

Answer 12

larger trabecular ducts that drain via intrahepatic ducts into right and left hepatic ducts.

Question 13

hepatocytes are collectively termed?

Answer 13

limiting plate, surrounding thebportal tract

Question 14

hepatocytes are collectively termed?

Answer 14

limiting plate, surrounding the portal tract

Question 14

hepatocytes are collectively termed?

Answer 14

limiting plate, surrounding the portal tract

Question 15

Reticulin of the liver

Answer 15

maintains the structural integrity of the liver, in form of a meshwork of reticulin fibers (collagen type 3)

Question 16

functions of reticulin

Answer 16

Supports hepatocytes and sinusoidal lining cells.

Merges with collagenous supporting tissue of portal tract and terminal hepatic venule.

At periphery of liver, reticulin is continuous with capsule that invests external surface of liver

Question 17

sinusoids lining

Answer 17

they are lined by fanestrated

Question 17

sinusoids lining

Answer 17

they are lined by fenestrated endothelium with no basement membrane, is separated from hepatocytes by narrow space which drains into lymphatics of portal tracts.

Question 18

Hepatic vasculature.

Answer 18

Hepatic portal vein and hepatic artery branch repeatedly within liver
Terminal branches run within portal tracts and empty into sinusoids

Blood from both systems filters between plates of hepatocytes in sinusoids which then drain into terminal hepatic venule

Bile secreted into bile canaliculi between plasma membranes of adjacent hepatocytes
Then drains into system of bile ducts in portal tracts

Question 19

name the structural unit of the liver ?

Answer 19

liver lobule.

Roughly hexagonal in shape, centred on a terminal hepatic venule
Portal tracts are positioned at angles of the hexagon

Blood from portal vein and hepatic arteries flows away from portal tract to adjacent central veins

Question 20

a physiologically useful model of liver anatomy?

Answer 20

hepatic acinus.

Question 21

a berry-shaped unit of liver parenchyma centred on the portal tract and lies between two or more terminal hepatic venules.

Answer 21

acinus.

blood flows from portal tracts through sinusoids to venules

Question 22

irregular hexagonal boundary at lobule is defined by

Answer 22

portal tract and space collagenous tissue.

Question 23

where do the sinusoids originate?

Answer 23

originate at lobule margin and course between plates of hepatocytes to converge upon terminal hepatic venule.

Question 24

plates of hepatocytes are?

Answer 24

are generally one cell thick and branch and anastomose to form a three-dimensional sponge.

Question 25

a muscular sac lined by simple columnar epithelium.

Answer 25

gallbladder

Question 26

submucosa.

Answer 26

relatively loose, rich in elastic fibers, blood vessels, and lymphatics which drain water reabsorbed from bile during the concentration process.

Question 27

The muscular layer wall of the gallbladder.

Answer 27

have fibers arranged in longitudinal, transverse and oblique orientations but do not form distinct layers. a thick collagenous adventitial coat is present.

Question 28

wall of the cystic Duct.

Answer 28

is formed into a twisted mucosa-covered fold which is known as the spiral valve of the heister.

Question 29

the flow of bile and pancreatic juice into the duodenum is controlled by?

Answer 29

hepatopancreatic sphincter which also allows for the prevention of reflux of the bile and pancreatic juice.

Question 30

lobulated gland covered by a thin collagenous capsule that extends as delicate septa between lobules.

Answer 30

pancreas

Question 31

pancreas is what type of gland is

Answer 31

both exocrine and endocrine gland exocrine component consists of closely packed acini which drains into a highly branched dust system. endocrine tissue forms islets of Langerhans of various size that is scatted around / throughout the exocrine tissue drains into blood system. Occasional adipocytes are scattered throughout parenchyma

Question 32

pancreatic acinus

Answer 32

is comprised of an irregular cluster of pyramid-shaped secretory cells, the apex of which surrounds a tiny central lumen.

Question 33

the smallest tributaries

Answer 33

known as intercalated ducts which drain into interlobar ducts in the septa of the gland

Question 34

The intercalated ducts

Answer 34

lined by simple cuboidal epithelia which become stratified in larger ducts. As the duct size increases, it becomes invested by a progressively thicker layer of dense collagenous tissue. wall of main pancreatic duct has smooth muscle present.

Question 35

The spleen

Answer 35

thin fibroelastic capsule has short trabeculae extending into parenchyma.

Question 36

the splenic parenchyma

Answer 36

is dark red( red pulp) with small white nodules ( white pulp) scattered throughout. Parenchyma permeated by interconnected network of sinuses (lined with endothelium) draining into larger sinuses which are tributaries of splenic vein

Question 37

Red pulp

Answer 37

loose tissue supported by reticulin fibers that are permeated by capillaries, some red pulp patches have no capillaries, instead have T and B lymphocytes.

Question 38

the most common tumors arising in pancreas, usually arise from pancreatic duct epithelium.

Answer 38

pancreatic adenocarcinoma. In the head of the pancreas, they would obstruct the common bile duct and result in painless obstructive jaundice In the body and tail of the pancreas, they are difficult to detect and are mainly found in autopsy examinations