Accessory Digestive Organs

Question 1

Liver Functions (3)

Answer 1

1. Metabolic- hepatocytes regulate circulating levels of nutrients; remove metabolic wastes and toxins
2. Hematological- processes and purifies blood from newly absorbed nutrients from small intestine
3. Digestive- produces and secretes bile

*largest visceral organ and has mass of ~1.5kg

Question 2

Accessory Digestive Organs (4) and Functions

Answer 2

-Liver, gallbladder, pancreas, salivary glands

-Produce, store, and secrete digestive enzymes and buffers
-Both the liver and pancreas have functions in other body systems

Question 3

Liver Location

Answer 3

-Immediately inferior to diaphragm, in right upper abdomen
-Sits superior and lateral to the stomach, right kidney and intestines

Question 4

Surfaces of Liver (2)

Answer 4

1. Diaphragmatic surface:
   -Superior and anterior surfaces, smooth and follows curve of diaphragm and body wall
   *Bare area: area of liver in direct contact with the diaphragm, no visceral peritoneum
2. Visceral surface:
   -Posterior and inferior surfaces, has impressions from the stomach, small intestine, right kidney and large intestine

Question 5

Lobes of the Liver (4)

Answer 5

1. Right lobe
2. Left lobe
3. Caudate lobe
4. Quadrate lobe

*gallbladder sits inferiorly, IVC sits superiorly

Question 6

Ligaments of the Liver (4)

Answer 6

1. Falciform ligament- attaches liver to anterior body well, divides into right and left lobes
2. Coronary ligament- suspends liver from diaphragm
3. Right and left triangular ligaments- on superior aspect towards lateral body wall (top corners)
4. Round ligament/ligamentum teres- thickening of inferior margin of falciform ligament, embryological remnant of umbilical vein

Question 7

Gallbladder Function

Answer 7

-Stores and concentrates bile produced by the liver
(Bile helps in digestion of dietary lipids through emulsification)

Question 8

Gallbladder Location

Answer 8

-Hollow, pear-shaped, muscular sac on right visceral surface of the liver
-Lateral to the stomach
-Closely related to the duodenum

Question 9

Ducts Connecting Gallbladder and Liver

Answer 9

-Right and left hepatic duct
-Common hepatic duct
-Cystic duct
-Common bile duct

*common hepatic duct joints cystic duct to form common bile duct, which empties into the duodenum

Question 10

Gallbladder Blood Supply

Answer 10

Arterial supply: cystic artery (branch of hepatic artery proper)

Venous drainage: cystic vein into hepatic portal vein (mirror arterial supply)

Question 11

Clinical Case: Gallstones

Answer 11

-Form when bile stored in gallbladder hardens into stone-like material
-Too much cholesterol, bile salts, or bilirubin (bile pigment) can cause gallstones
-Treatment is surgery

Question 12

Porta Hepatis Components (3)

Answer 12

A.k.a hilum of liver, region that contains:

1. Portal vein
2. Hepatic artery proper
3. Common hepatic duct

Question 13

Origin of Artery in Porta Hepatis

Answer 13

Abdominal aorta -> celiac trunk -> common hepatic artery -> hepatic artery proper

Question 14

Origin of Vein in Porta Hepatis

Answer 14

-Union of the superior mesenteric vein and splenic vein (posterior to pancreas) forms the hepatic portal vein
-Portal vein carries venous blood from the small and large intestines, stomach, pancreas, gallbladder, spleen

Question 15

Hepatic Portal System

Answer 15

Portal system= connection between 2 capillary beds

-Nutrient-rich venous blood drains from veins of the stomach and intestines and travels to the liver for processing

Question 16

Processing at the Liver

Answer 16

-Lobules are the functional unit of the liver
-They are hexagonal
-At the centre of each lobule there is a central vein, and at each corner there’s a portal area containing a portal triad

-As blood flows towards the centre, hepatocytes absorb and secrete substances, altering the blood entering systemic circulation.
-Blood provided by the hepatic artery proper and the hepatic portal vein flows from portal area towards the central vein, which coalesce into hepatic veins

Question 17

Portal Triad

Answer 17

-Small branch of the hepatic portal vein
-Small branch of the hepatic artery proper
-A bile duct

Question 18

Scenario: Alcohol Consumption

Answer 18

1. The alcohol passes from the oral cavity to the esophagus and into the stomach
2. The stomach and small intestine absorb the alcohol
3. The hepatic portal vein carries the blood to the liver
4. Enzymes metabolize alcohol in the liver
5. Hepatic veins carry the blood to the IVC to go back into systemic circulation

Question 19

Bile Flow to Portal Areas

Answer 19

Right and left hepatic ducts form common hepatic duct

-Hepatocytes produce bile which flows outward to portal areas
-Small projections called bile canaliculi carry bile to the bile duct of the closest portal area

Question 20

Summary of Porta Hepatis

Answer 20

-Hepatic artery proper delivers oxygenated blood to the liver
-Hepatic portal vein delivers deoxygenated, but nutrient-rich blood from the digestive tract
-Common hepatic duct carries bile produced by the liver away

Question 21

Pancreas: Exocrine and Endocrine Functions

Answer 21

Exocrine:
-Produces digestive enzymes and alkaline buffers to neutralize acidic chyme
-Duct system within pancreas carries the fluid to the duodenum

Endocrine:
-Produces hormones like insulin
-Secreted into interstitial fluid and then into bloodstream

Question 22

Appearance and Location of the Pancreas

Answer 22

~15cm long
-Pinkish/grey in colour
-Located posterior to stomach
-Head of the pancreas is nestled in the curve of the duodenum
-Extends left towards the spleen

*area of abdominal romance= head of pancreas is enfolded in arms of duodenum

Question 23

Parts of the Pancreas (5)

Answer 23

-Tail
-Body
-Neck
-Head
-Uncinate process

Question 24

Blood Supply to the Pancreas

Answer 24

Arterial supply: branches of the splenic artery and the pancreaticduodenal artery

Venous drainage: splenic vein

Question 25

Gallbladder and Pancreas Emptying

Answer 25

-Secretions from the gallbladder and pancreas are transported to the duodenum via duct systems
-The fluids enter the duodenum through papillae
-A papilla is a small, rounded protuberance on an organ or part of the body