case 3 anatomy

Question 1

histology of salivary glands

Answer 1

The secretory units of the salivary glands consist of a branched tubulo-acinar structure. The acinar cells produce either serous, mucous or a mixed saliva. In some cases the serous cells form caps around the mucous secreting acini. These caps are referred to as serous demilunes. Cells which produce serous saliva stain much darker with H&E stain compared to mucous secreting cells.

The acini cells secrete saliva into small intercalated ducts which, in turn, drain into larger striated ducts and then into even larger excretory ducts.

Question 2

histology of the pancreas

Answer 2

The pancreas is a mixed endocrine and endocrine gland. It is surrounded by a thin connective tissue capsule. Septa extend into the gland from the capsule separating the pancreatic lobules.

The exocrine component of the gland is similar to the parotid gland. It consists of closely packed secretory acini which drain into a duct system. The smallest intercalated ducts drain into intralobular ducts which, in turn, drain into interlobular ducts. The interlobular ducts are located in the septa of the gland. The interlobular ducts drain into either the main pancreatic duct or the accessory pancreatic duct.

The endocrine component of the gland is comprised of clusters of cells known as the pancreatic islets (islets of Langerhans). These are scattered throughout the gland but are most numerous in the tail. The islets vary in size and are composed of a number of different cell types, each of which is responsible for secreting one type of hormone.

Question 3

histology of the liver

Answer 3

The liver is covered by a thin capsule, termed Glisson’s capsule. The capsule is thicker at the porta hepatis and it surrounds the vessels and ducts as they extend into the gland. The hepatocytes and the sinusoids are surrounded by a fine, supportive reticular network. the liver lobule is also important in the histological sections.

Question 4

porta hepatis

Answer 4

deep fissure in the inferior surface of the liver through which all the neurovascular structures (except hepatic veins) and hepatic ducts enter or leave the liver. It contains: right and left hepatic ducts. right and left branches of hepatic artery. portal vein.

Question 5

gall bladder

Answer 5

The wall of the gall bladder is similar to that of the gastrointestinal tract but it lacks the submucosal layer. The mucosa consists of a layer of simple columnar epithelium and a supporting lamina propria. There is no distinct submucosa and only one muscularis is evident. This is a thin layer which is composed of muscle fibres orientated in many directions. The outer layer of the gall bladder is serosa in parts and an adventia in others

Question 6

biliary tree

Answer 6

liver-right and left hepatic ducts-common hepatic duct-gallbladder-cystic duct-bile duct-hepatopancreatic ampulla-duodenum. If fat is present in the duodenum the sphincter of Oddi (hepatopancreatic sphincter) will be open and bile will be able to enter. In the absence of fat, the sphincter will be closed and the bile will track back up the bile duct, into the cystic duct and into the gall bladder.

Question 7

What is the name given to the hormone that is released by the enteroendocrine cells when fat is present in the duodenum?

Answer 7

cholecystokinin (CCK)

Question 8

what splanchnic nerve provides symp innervation to the gall bladder

Answer 8

greater splanchnic as in the forgut so T5-9

Question 9

which ganglion do postganglionic symp fibres for the gall bladder arise

Answer 9

coeliac

Question 10

which nerve transmits parasymp to the gall bladder

Answer 10

vagus

Question 11

gall bladder blood supply

Answer 11

he arterial supply to the gall bladder is provided through the cystic artery. The custic artery arises from the right hepatic artery. The cystic artery is usually located in the triangle (cystohepatic) between the inferior border of the liver, cystic duct and common hepatic duct.
Venous drainage - the fundus and body is drained directly through the visceral surface of liver into hepatic sinusoids. the neck and cystic duct are drained by cystic veins which drain into the liver directly or via portal vein.

Question 12

lymphatic drainage of the gall bladder

Answer 12

cystic nodes-hepatic nodes-coeliac nodes-intestinal trunk-cisterna chyli-thoracic duct-left subclavian vein

Question 13

fundus of gall bladder

Answer 13

Rounded portion of the gall bladder that projects from the lower border of the liver. Located at the tip of the 9th costal cartilage in the midclavicular line.

Question 14

body of the gall bladder

Answer 14

Main part of gall bladder that is located posterior to the liver, superior part of duodenum and the transverse colon.

Question 15

neck of the gall bladder

Answer 15

The part of the gall bladder which is continuous with the cystic duct, it lies superior to the duodenum.

Question 16

innervation of the liver

Answer 16

symp by greater splanchnic as in forgut, goes into coeliac ganglion. Vagus does parasymp.

Question 17

lymphatic drainage of the liver

Answer 17

The liver produces up to half the lymph that is made in the body. Most of the lymph from the liver drains into the hepatic nodes which are located at the porta hepatis.

Question 18

portal/systemic anastomoses

Answer 18

Anastomoses between the hepatic portal system and the systemic circulation allow communication between the two vascular systems. If portal circulation through the liver is obstructed blood can return to the heart via the systemic circulation. As the portal vein and its tributaries have no valves the blood can flow in a retrograde direction to the IVC.

Question 19

anastamoses at the inferior oesophagus

Answer 19

Lower third drains via left gastric vein into portal vein - middle third drains into azygos vein.

Question 20

anastamoses at anal canal

Answer 20

Superior rectal veins drain into portal system - middle and inferior rectal veins drain into internal iliac and internal pudendal veins.

Question 21

anastamoses at secondary retroperitoneal structures

Answer 21

Superior mesenteric, inferior mesenteric and splenic vessels drain into portal system - renal, lumbar and phrenic veins drain into IVC.

Question 22

anastamoses at anterior abdominal wall

Answer 22

Paraumbilical veins drain into portal system – superficial veins of abdomen drain into axillary or femoral veins.

Question 23

vascular supply of the liver

Answer 23

hepatic artery proper delivers 20-25% of blood to the liver, which comes from the common hepatic artery. The hepatic artery proper bifurcates into right and left hepatic arteries which enter the liver at the porta hepatis.The portal vein (hepatic portal vein) delivers 75-80% of blood to the liver. It transports blood poor in oxygen but rich in nutrients from the abdominal organs to the liver.The portal vein is formed posterior to the neck of the pancreas. The splenic and sup mesenteric make the portal vein.

Question 24

blood flow of the liver

Answer 24

branches of the hepatic artery and portal vein enter the portal triad. blood is conveyed through the liver sinusoid, drains into the central vein, into the R or L hepatic vein, the vessels drain into the inf vena cava.

Question 25

liver lobule

Answer 25

The liver is a solid organ composed of tightly packed epithelial cells (hepatocytes). The classical description of the liver suggests that the basic structural unit of the liver is the liver lobule. Each lobule is hexagonal in shape and consists of plates of hepatocytes radiating towards a central vein. Vascular channels, the liver sinusoids, are placed between the plates of hepatocytes. They convey blood from the periphery of the lobule to the central vein. A portal triad is located at each angle of the hexagonal lobule. Each portal triad contains a branch of the hepatic artery and of the portal vein (which deliver blood to the lobule) and a small bile duct. Bile is secreted by the hepatocytes into small bile canaliculi which are located between adjacent hepatocytes. The canaliculi drain into the small bile duct at the portal triad. This arrangement is designed so that blood and bile don’t mix.

Question 26

falciform ligament

Answer 26

A double fold of peritoneum that connects anterior & superior surfaces of the liver to the anterior abdominal wall.

Question 27

ligament teres

Answer 27

Remnant of the umbilical vein, it runs in the free edge of the falciform ligament.

Question 28

ligamentum venosum

Answer 28

Remnant of the ductus venosus, it is attached to the portal vein and the IVC.

Question 29

coronary ligament

Answer 29

A reflection of visceral peritoneum that extends from the posterior surface of the liver onto the diaphragm.

Question 30

right triangular ligament

Answer 30

The right extremity of the coronary ligament.

Question 31

left triangular ligament

Answer 31

The left extremity of the coronary ligament.

Question 32

hepatogastric ligament

Answer 32

The part of the lesser omentum which extends from liver to lesser curvature of stomach.

Question 33

hepatoduodenal ligament

Answer 33

The free border of the lesser omentum, it contains the bile duct, portal vein and hepatic artery.

Question 34

lobes of the liver

Answer 34

right left caudate quadrate. Right and left seperated falciform.

Question 35

liver relations

Answer 35

in R and L hypochondriac and epigastric. The liver has two surfaces; diaphragmatic and visceral. The diaphragmatic surface is smooth as it is moulded by the under surface of the diaphragm. In contrast the visceral surface is irregular as it is in contact with the irregular shaped viscera. anterior to liver: ant abdom wall. xiphoid process.costal margins. pleura. lungs.
posterior to liver: gall bladder. duodenum. stomach, hepatic flexure. IVC. Oesophagus. R kidney. colon

Question 36

vascular supply of the pancreas

Answer 36

The head (including ucinate process) of the pancreas are supplied by the superior and inferior pancreaticoduodenal arteries. The remainder of the pancreas is supplied by the splenic artery. superior PD is a branch of GD, which comes from the CH. the IPD comes from SM. The head of the pancreas is drained by the superior and inferior pancreaticoduodenal veins. The remainder of the pancreas is drained by the splenic vein.

Question 37

pancreatic ducts

Answer 37

The secretory acini cells secrete pancreatic juice into a series of ducts. The duct system empties into the second part of the duodenum via the main pancreatic and accessory pancreatic ducts. accesory just drains the head. the main joins common bile to go to major duodenal papilla. Accesory can be absent. The flow of bile and pancreatic juice into the duodenum is controlled by the hepatopancreatic sphincter, this sphincter also prevents reflux of duodenal content back into the pancreatic and bile ducts.

Question 38

what plane is the pancreas

Answer 38

transpyloric

Question 39

relations of the pancreas

Answer 39

Anterior: transverse mesocolon. lesser sac. stomach. transverse colon. GDA.
Posterior: aorta. Splenic vein. left suprarenal gland. IVC. Bile duct. SMA. left psoas muscle. hilum of spleen. left kidney. renal vessels. PV.