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ESA1 - Body Logistics > Liver > Flashcards

Flashcards in Liver Deck (25)
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1
Q

How many litres of bile do we produce per day?

A

1 litre

2
Q

What is the hepatic portal system?

A

The hepatic portal system is the system of veins comprising the hepatic portal vein and its tributaries.

3
Q

What is the hypothalamo-hypophyseal portal system?

A

The hypophyseal portal system is a system of blood vessels in the brain that connects the hypothalamus with the anterior pituitary.

4
Q

How do portal circulatory systems differ from the typical circulatory route?

A

The blood passes through two sets of smaller vessels before returning to the heart

5
Q

Where does blood from the first set of capillaries in a portal system collect?

A

In portal vessels (portal veins)

6
Q

What is the function of the hepatic portal system?

A

It is responsible for directing blood from parts of the gastrointestinal tract to the liver

7
Q

What is travelling in the portal vein?

A

Water, water soluble vitamins, electrolytes, carbohydrates, proteins, intestinal hormones and toxins, including ammonia

8
Q

Can ammonia cross the blood-brain barrier?

A

Yes!

9
Q

The liver is the only organ in the body is which what cycle is expressed?

A

The complete urea cycle - converts ammonia to urea which can then be excreted in the urine

10
Q

What is not travelling in the portal vein?

A

Lipids and fat soluble vitamins (A, D, E and K) which go into lacteals

11
Q

Lipids are taken into cells and processed into what?

A

Chylomicrons, which are taken up by lymphatics called lacteals

12
Q

What are lacteals?

A

Specialised lymphatic vessles that drain into the abdominal lymphatics that then drain into the thoracic duct which joins the venous system at the junction of the left internal jugular vein and subclavian vein.

13
Q

How do chylomicrons enter the liver?

A

Hepatic artery

14
Q

What are the functions of the liver?

A

Metabolism, storage, detoxification, bile production

15
Q

What does the liver store?

A

Glycogen, iron, vitamins A, B12, D and K

16
Q

What does the liver produce?

A

Bile, albumin, glycogen, numerous coagulation factors, complement components of immune system

17
Q

What does the liver break down?

A

Drugs (cytochrome P450), hormones, haemoglobin, poisons

Can also take over removal of aged red cells after splenectomy

18
Q

What are cytochrome p450s?

A

Family of haem containing isoenzymes which ae located in the smooth ER of several tissues, metabolise poisons and drugs

19
Q

What are Kupffer cells?

A

Specialized macrophages located in the liver, form part of the lining of sinusoids

20
Q

What is a sinusoid?

A

An irregular tubular space for the passage of blood, taking the place of capillaries and venules in the liver, spleen and bone marow.

21
Q

How are human liver lobules classically described?

A

Hexagonal

22
Q

What are Stellate (Ito) cells full of?

A

Cytoplasmic vacuoles cotaining vitamin A

23
Q

In liver cirrhosis, what happens to hepatic stellate cells?

A

They lose their vitamin A storage capability and differentiate into myofibroblasts which synthesise and deposit collagen within the perisinusoidal space, resulting in liver fibrosis.

24
Q

How is portal hypertension caused in patients with cirrhosis?

A

Collagen deposited by the myofibroblasts surrounds the central vein, constricting it

25
Q

What makes up the portal triad?

A

Proper hepatic artery, hepatic portal vein and common bile duct