Liver And Hepatic Function

Question 1

What does an endocrine gland do

Answer 1

Secretes something directly into the blood stream not via a duct

Question 2

What does an exocrine gland do

Answer 2

Secretes something onto an epithelial surface via a duct

Question 3

What are some key functions of the liver

Answer 3

Makes glycogen from glucose and stores it
Synthesis of lipids
Synthesis of proteins
Amino acid synthesis
Protein degradation
Breakdown of drugs, alcohol, hormones
Production and secretion of bile

Question 4

What is lipolysis

Answer 4

Breakdown of lipids into fatty acids also makes lipoproteins, phospholipids, cholesterol and other lipids

Question 5

Low levels of what can indicate liver dysfunction

Answer 5

Albumin which is an abundant protein found in the blood

Question 6

Which vitamins does the liver store

Answer 6

Fat soluble vitamins
Vitamin A, D, E and K
Vitamins A and B12 for up to 4 years and D for months

Question 7

What minerals can the liver store

Answer 7

Iron and copper

Question 8

What does the liver do with ammonia

Answer 8

Gets it from the intestines via portal circulation
Turns it into urea through the urea cycle (series of reactions)
The urea is put back into the circulation then excreted by the kidneys

Question 9

What does the liver do with ethanol

Answer 9

The enzyme alcohol dehydrogenase turns ethanol into acetaldehyde which the build up of makes you feel ill when drinking too much

Question 10

What does the liver do with drugs

Answer 10

They are metabolised by cytochrome P450 enzymes
Some drugs can induce P450s and increase their levels which make other drugs get broken down too fast

Question 11

What is the cephalic phase

Answer 11

Preparation for digestion, vagus nerve stimulates secretions

Question 12

What is the gastric phase

Answer 12

Pancreatic secretions are stimulated by the distension of the stomach

Question 13

What is the intestinal phase

Answer 13

Hormones are released in response to H+ and amino acids, fatty acids which stimulate pancreatic secretions

Question 14

What do acinar cells in the pancreas release

Answer 14

Zymogen granules containing digestive enzymes by exocytosis

Question 15

What do acinar cells do

Answer 15

Move out NA+ causing water to follow into the duodenum
They are intercalated duct cells in the pancreas also regulate ion movement via the cystic fibrosis transmembrane conductance regulator Cl- channel and other ion channels
Bicarbonate is secreted which neutralises the acid as food comes into the duodenum from the stomach

Question 16

What organ produces hepatic bile

Answer 16

Liver produces and secretes it

Question 17

What is the common hepatic duct

Answer 17

Hepatocytes secrete bile into canaliculi which feed into larger ducts until they form the duct

Question 18

What controls the path of bile

Answer 18

The sphincter of oddi

Question 19

What are the 2 pathways where bile can go

Answer 19

Into the duodenum via common bile duct when SO is relaxed
Into the gallbladder via cystic duct when SO is contracted

Question 20

Where is bile stored

Answer 20

In the gallbladder in a concentrated form

Question 21

How is the stored bile released

Answer 21

CCK causes the gallbladder to contract and expel bile and also causes the sphincter of oddi to relax

Question 22

What does bile do

Answer 22

Key for lipid digestion they emulsify fats during digestion increasing the surface area of lipids and allows enzymes to work efficiently

Question 23

What gives bile its colour

Answer 23

Bilirubin made from broken down haemoglobin

Question 24

What helps solubilise the bile salts

Answer 24

Phospholipids

Question 25

What does the spleen do

Answer 25

Removes old red blood cells and keeps a spare storage of blood in case of haemorrhage
Also makes antibodies and removes antibody coated bacteria and cells through the lymph and blood

Question 26

What is liver disease most commonly caused by

Answer 26

Obesity
Alcohol misuse
Hepatitis

Question 27

What do abnormal liver functions cause

Answer 27

Trouble metabolising drugs also goes for kidney disease
Impaired other functions such as protein synthesis