Digestive System (Liver and Pancreas)

Question 1

What is the main function of the pancreas

Answer 1

Secrete digestive enzymes that act in the small intestine
Secrete hormones

Question 2

What is the main function of the liver?

Answer 2

Secrete bile that helps in fat digestion
Metabolize carbohydrate, fat and protein to detoxify toxic substances and drugs

Question 3

What are the two types of pancreas?

Answer 3

Exocrine and endocrine

Question 4

Exocrine pancreas

Answer 4

95% of pancreatic mass with acinar and centroaciner cells

Question 5

Acinar cells

Answer 5

Secrete enzymes first secreted as pro-enzymes then activated in the small intestine

Question 6

Centroacinar cells

Answer 6

Secrete large quantities of enzyme-poor alkaline fluid that neutralizes acidic chyme

Question 7

What are the centroacinar cell secretions controlled by?

Answer 7

Enzymatic: cholecystokinin hormone
Alkaline fluid: regulated by secretin hormone
Both hormones produced by enteroendocrine cells

Question 8

What are the pancreatic ducts?

Answer 8

Intercalated, intralobuar and interlobular that bring the pancreatic secretion into the duodenum

Question 9

Endocrine pancreas

Answer 9

Islets of Langerhans with:
Alpha cells (20%)- produce glucagon and elevate blood glucose
Beta (70%)- produce insulin to decrease blood glucose level
Delta (5%)- produce somatostain that regulates secretion of alpha and beta cells

Question 10

Liver

Answer 10

Largest glands of the body
Lobes and lobules
Enclosed by CT
Has portal verin, hepatic artery, hepatic vein, lymph vessels and hepatic ducts

Question 11

Portal vein

Answer 11

Brings blood from the gut
70% of the functional blood supply
All materials absorbed via the intestine reach liver via PV except chylomicrons

Question 12

Hepatic artery

Answer 12

Brings arterial blood from the aorta
20-30% nutritional

Question 13

Hepatic vein, Lymph vessels and hepatic duct

Answer 13

Vein: takes blood away to the heart
Vessels: drain lymph
Duct: transport bile to the duct

Question 14

Liver lobule

Answer 14

Easily recognized in pig and camel
Hexagonal mass with central vein, plates of hepatocytes (peripheral), sinusoids, and portal triad

Question 15

Sinusoids blood supply

Answer 15

Receive blood from portal vein and hepatic artery and drain into central vein

Question 16

What are the 2 main structural and functional parts of the liver lobule?

Answer 16

Sinusoids and hepatic plates

Question 17

Sinusoid characteristics

Answer 17

Wide lumen
Fenestrated endothelial cells
Discontinuous BL
Space of Disse (surrounding space)
Kupffer cells

Question 18

Kupffer cells

Answer 18

O: monocytes
F: remove foreign particles and old RBCs (phagocytize)

Question 19

Hepatocytes

Answer 19

Polyhedral cells with 1 or 2 nuclei
Well-developed RER, SER and Golgi, lysosomes, peroxisomes
Bile canaliculi

Question 20

Bile canaliculi

Answer 20

Small tunnel like extensions of intercellular spaces
Receive bile from hepatocytes and carry it o canals of Herring

Question 21

Hepatic functions

Answer 21

Exocrine: production and release of bile
Endocrine: plasma protein
Metabolic: storing glycogen and lipids
Gluconeogenesis
Detoxification

Question 22

Classification of liver lobules

Answer 22

Classical and portal lobules

Question 23

Classical lobule

Answer 23

Hexagonal
Central vein
Portal triads at each corner

Question 24

Portal lobule

Answer 24

Triangular in cross section
Central vein @ each corner of triangle
Portal triad in the center

Question 25

Hepatic acinus of Rappaport

Answer 25

Diamond shaped regions
Central vein at two ends of the diamond
Portal triad in center

Question 26

Liver regeneration

Answer 26

Cell renewal slow in a healthy liver
If three fourths surgically removed it can regenerate to its original in a short period of time

Question 27

Gall bladder

Answer 27

Sac-like structure
Lined by simple columnar with microvilli
F: store and concentrate bile bu absorbing fluid and some electrolytes

Question 28

Which animal doesn’t have a gall bladder?

Answer 28

Horses