Colon Cancer + Haemorrhoids + Myocardial Infarction (14)

Question 1

What is Dukes’ staging?

Answer 1

Question 2

What are hemorrhoids?

Answer 2

Swollen or inflamed anal cushions

Question 3

What is the pathogenesis of hemorrhoids?

Answer 3

• The anal cushions function normally when they are fixed to their proper sites within the anal canal by fibromuscular ligaments, which are the anal remnants of the longitudinal layer of the muscularis propria from the rectum (Treitz’s ligaments).
• When these submucosal fibres fragment (as by prolonged and repeated downward stress related to straining during defecation), the anal cushions are no longer restrained from engorging excessively with blood and may result in bleeding and prolapse.

Question 4

What is the pathogenesis of thrombosed hemorrhoids?

Answer 4

• Acute thrombosis results from sudden raised pressure causing rupture of the vascular plexus leading to a blood clot at the anal verge.
• Any activity requiring excessive abdominal straining such as over-exercising can cause this.

Question 5

Why do coronary arteries get thrombosed?

Answer 5

Due to coronary artery atherosclerosis.

Question 6

What is the function of thrombus?

Answer 6

A thrombus is a healthy response to injury intended to prevent bleeding.

Question 6

What is melanosis coli?

Answer 6

It is a disorder of pigmentation of the wall of the colon, often identified at the time of colonoscopy. It is benign and may have no significant correlation with disease.

Question 7

What are the risk factors of atherosclerosis?

Answer 7

• Non-modifiable (Constitutional): Genetic abnormalities, Family History, Increasing age, Male gender
• Modifiable: Hyperlipidemia, Hypertension, Cigarette smoking, Diabetes, Inflammation

Question 7

What is adenoma?

Answer 7

The term adenoma is generally applied to benign epithelial neoplasms producing gland patterns and to neoplasms derived from glands but not necessarily exhibiting glandular patterns.

Question 8

How is thrombus formed?

Answer 8

• An atheromatous plaque is suddenly disrupted by intra-plaque hemorrhage or mechanical forces, exposing sub-endothelial collagen and necrotic plaque contents to the blood.
• Platelets adhere, aggregate, and are activated, releasing thromboxane A2, adenosine diphosphate (ADP), and serotonin—causing further platelet aggregation and vaso-spasm.
• Activation of coagulation by exposure of tissue factor and other mechanisms adds to the growing thrombus.
• Within minutes, the thrombus can evolve to completely occlude the coronary artery lumen.

Question 8

What is the mechanism of myocardial infarction?

Answer 8

• Vascular obstruction causes a rapid loss of contractility in cardiac myocytes.
• This is due to a drop in ATP and accumulation of harmful metabolites.
• Early changes are potentially reversible, but severe ischemia can cause irreversible damage and myocyte death.
• Ultrastructural changes, such as myofibrillar relaxation, glycogen depletion, and cell swelling, also occur rapidly.
• These changes are associated with myocardial infarction.