S8) The Liver Flashcards Preview

ESA1: Body Logistics > S8) The Liver > Flashcards

Flashcards in S8) The Liver Deck (17)
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1
Q

Describe the hepatic portal system

A

The hepatic portal circulatory system involves blood passing through two sets of smaller vessels before returning to the heart

2
Q

Identify 6 types of substances which travel to the portal vein

A
  • Water
  • Water soluble vitamins
  • Electrolytes
  • Carbohydrates e.g. glucose, galactose, fructose
  • Proteins e.g. amino acids, dipeptides, tripeptides
  • Toxins e.g. ammonia, chemicals, pathogens
3
Q

Identify 2 types of substance which do not travel through the portal vein

A
  • Lipids
  • Fat soluble vitamins (ADEK)
4
Q

What are dietary lipids?

A

Dietary lipids are mostly triglycerides, cholesterol and phospholipids

5
Q

How are lipids absorbed?

A
  • Lipids are digested by lipases
  • Lipids are taken into the cells and processed into chylomicrons
  • Chylomicrons are taken up by lacteals
6
Q

Identify the 5 major functions of the liver

A
  • Storage
  • Anabolism
  • Catabolism
  • Exocrine secretion
  • Endocrine secretion
7
Q

Identify 3 substances which are stored by the liver

A
  • Iron
  • Glycogen
  • Vitamins
8
Q

Identify 3 substances which are produced by the liver

A
  • Albumin
  • Glycogen
  • Coagulation factors
9
Q

Identify 3 substances which are broken down by the liver

A
  • Drugs
  • Hormones
  • Haemoglobin
10
Q

Identify an exocrine secretion of the liver

A

Bile via bile duct

11
Q

Identify 3 substances which are secreted by the liver into the blood

A
  • Angiotensinogen
  • Thrombopoietin
  • IGF-1
12
Q

Hepatocytes constitute 80% of the liver cell population and can regenerate.

Describe 6 other unique features of hepatocytes

A
  • Numerous mitochondria
  • Numerous peroxisomes (full of oxidising agents)
  • Numerous free ribosomes
  • Numerous rough and smooth ER
  • Numerous Golgi complexes
  • Glycogen deposits
13
Q

What are Kupffer cells and what do they do?

A
  • Kupffer cells are monocyte derived specialist macrophages that form part of the lining of the sinusoids.
  • They patrol the sinusoids, recycling old red blood cells and ingesting pathogens
14
Q

What is a sinusoid and what is unique about its structure?

A
  • A sinusoid is an irregular tubular space for the passage of blood in the liver, spleen and bone marrow
  • Its endothelium is perforated with large holes, allowing Kupffer cells to migrate into liver tissue at sites of inflammation and damage
15
Q

What are stellate cells?

A

Stellate cells are liver cells which are full of cytoplasmic vacuoles containing Vitamin A

16
Q

In three steps, describe what happens to stellate cells during liver cirrhosis?

A

⇒ Differentiate into myofibroblasts

⇒ Synthesise and deposit collagen within the perisinusoidal space, resulting in liver fibrosis

⇒ The collagen surrounds and constricts the portal vein, leading to portal hypertension

17
Q

Where do lymphatic vessels rise and drain in the liver?

A

Lymphatics arise from the periportal space of Mall and drain to the liver hilum and then into the hepatic duct