Liver

Question 1

Why is the liver brown?

Answer 1

High density of mitochondria

Question 2

How much bile do we produce per day?

Answer 2

1L

Question 3

What are the two types of portal systems?

Answer 3

Hepatic portal system

Hypothalamo-hypophyseal portal system

Question 4

How are the portal circulatory systems different from the typical circulatory route?

Answer 4

Blood passes through two sets of smaller vessels before returning to the heart. Blood from the first set of capillaries collects in portal vessels which then branch again to supply a capillary network to a second location before entering veins which lead to the heart

Question 5

What travels in the portal vein? (7)

Answer 5

Water
Water soluble vitamins
Electrolytes (Na, K, Cl etc)
Carbohydrates 
Proteins
Intestinal hormones (pancreatic)
Toxins, including ammonia

Question 6

True or false: ammonia can cross the blood brain barrier

Answer 6

TRUE

Question 7

True or false: the liver is the only organ in the body in which the complete urea cycle is expressed

Answer 7

TRUE

Question 8

What is not travelling in the portal vein?

Answer 8

Lipids

Fat soluble vitamins (A, D, E and K)

Question 9

Define chylomicron

Answer 9

Droplet of fat present in blood or lymph after absorption from small intestine

Question 10

Complete the sentences:

Dietary lipid is mostly ________________, ___________ and _______________ and they are digested by lipases. The process needs ____ acids to form ________. Lipids are taken into cells and processed into ____________. These are taken up by lymphatics, called _________ and these contain _____.

Answer 10

Triglycerides 
Cholesterol 
Phospholipids 
Bile
Micelles 
Chylomicrons 
Lacteals
Chyle

Question 11

What are the functions of the liver? (4)

Answer 11

1. Metabolism (cat/anabolism)
2. Storage
3. Detoxification
4. Bile production

Question 12

What does the liver store? (6)

Answer 12

Iron
Vitamin A
Vitamin B12
Vitamin D
Vitamin K
Glycogen

Question 13

The liver is involved in the catabolism of which substances?

Answer 13

Drugs (cytochrome P450)
Hormones
Hb
Poisons (cytochrome P450)

Question 14

What is cytochrome P450?

Answer 14

Family of haem-containing isoenzymes which are located in the SER of several tissues

Question 15

True or false: the liver cannot take over the removal of aged RBCs after a splenectomy

Answer 15

FALSE

Question 16

What is a Kupffer cell?

Answer 16

Phagocytic cell in liver which is involved in the breakdown of RBCs

Question 17

In terms of the liver’s endocrine function, what does it produce? (3)

Answer 17

Angiotensinogen
Thrombopoetin
Insulin like growth factor 1 (IGF-1)

Question 18

What does the liver modify to its active form?

Answer 18

Vitamin D

Thyroxine

Question 19

What does the liver break down? (4)

Answer 19

Insulin
Glucagon
Oestrogen
Progesterone

Question 20

What is a sinusoid?

Answer 20

Irregular tubular space for the passage of blood, taking the place of capillaries and venues in the liver, spleen and bone marrow

Question 21

True or false: human liver lobules are described as polygonal but are more accurately described as hexagonal

Answer 21

FALSE - other way round

Question 22

What % of the tissue macrophages of the body do Kupffer cells constitute for?

Answer 22

80%

Question 23

Stellate (Ito) cells are full of cytoplasmic vacuoles containing what?

Answer 23

Vitamin A

Question 24

What happens in liver cirrhosis?

Answer 24

Hepatic stellate cells lose their vitamin A storage capability and differentiate into myofibroblasts that synthesise and deposit collagen within the perisinusoidal space, resulting in liver fibrosis. This collagen surrounds the central vein, constricting it and leading to portal hypertension