Liver/ GIT

Question 1

List what is required for the digestion, adsorption and metabolism of nutrients? How/why may malabsorption of nutrients by the GIT occur?

Answer 1

To absorb proteins and carbohydrates we need pancreatic and brush border enzymes whereas fat
absorption requires these as well as bile from the liver. To adequately absorb nutrients we need a
large surface area present in the small intestine and to use nutrients we need the metabolic functions of the liver.

Malabsorption can occur if the site of absorption is compromised, the small intestine (SI) is the site
where most nutrients are absorbed thus there is a large surface area here (cells with microvilli, villous
structures and plicae). If there is a reduction in surface area, there will be malabsorption of all
nutrients. Diseases that can affect the SI include Crohn’s, ulcers, cancers, and some food intolerances that cause atrophy of villi

Question 2

List the risk factors for the development of cancers of the tube & accessory organs? Explain the pathogenesis where known.

Answer 2

Aging, alcohol, Smoking

Question 3

List the possible consequences of chronic inflammatory bowel diseases

Answer 3

Cancer
Scarring which can lead to adhesions, fistula formation & obstruction.
Chronic blood loss leading to anaemia.
Malabsorption. Pain & bloody diarrhoea

Question 4

List the risk factors for the development of gall stones & some of the possible consequences of having them?

Answer 4

Risk factors: Fat, female, fertile, forties, family history
High oestrogen
rapid weight loss

Consequences
Pain; acute and chronic cholecystits & chronic inflammation increasing the risk or cancer; obstruction leading to cholestasis & cirrhosis, pancreatitis, jaundice & malabsorption

Question 5

List the main causes of cirrhosis

Answer 5

chronic alcohol intake,
NAFLD,
hepatitis,
autoimmune disease,
iron-overload (hemochromatosis),
biliary disease,
heart failure

Question 6

Cirrhosis & Liver Failure:
– Explain the potentially life threatening conditions that cirrhosis can cause even before it has led to complete failure of the liver.
– Explain how the effects of liver failure can worsen or exacerbate the conditions caused by cirrhosis.
– List the major effects that liver failure has on the body in addition to those described in response to the previous learning objectives

Answer 6

1. Cirrhosis increases the risk of hepatocellular carcinoma forming in fact it is not unusual to have
   multiple primary cancers in a cirrhotic liver due to the massive proliferation of hepatocytes.
2. Diffuse scarring of the liver leads to compression and obstruction in the veins within the liver
   leading to Portal hypertension (increased pressure in the portal VENOUS system). This causes the
   veins to dilate and become congested forming varices. The veins are engorged, full of blood and prone to rupture particularly the oesophageal varicose veins (varices), which are within the comparatively thin walled oesophagus which is exposed to stress. When these varices rupture we can bleed internally leading to exsanguination and death from hypovolemic shock.
3. Encephalopathy due to increased ammonia levels In the blood, leading to disruption of the CNS and potentially coma and death.
4. Cirrhosis causes portal hypertension leading to congestion which increases hydrostatic pressure
   leading to oedema & ascites (transudate).
5. Liver failure leads to reduced synthesis of plasma proteins leading to reduced colloidal pressure worsening the oedema & ascites (transudate).
6. Cirrhosis leads portal hypertension leading to congested veins which are prone to rupture &
   haemorrhage particularly those in the oesophagus
   .
7. Liver failure leads to reduced synthesis of clotting factors & vitamin K which is a co-factor required for certain coagulation factors (2, 7, 9 & 10) thus liver failure reduces the ability of blood to clot.