Week 4 - Prerequisite knowledge

Question 1

What are the main components of blood composition?

Answer 1

• Plasma (water, proteins—albumin & globulins—nutrients, hormones, ions, gases)
• Formed elements (RBCs, WBCs, platelets)

Plasma serves as the liquid medium, while formed elements include red blood cells, white blood cells, and platelets.

Question 2

What is the lifespan of RBCs?

Answer 2

Approximately 120 days

RBCs transport oxygen and carbon dioxide through hemoglobin.

Question 3

What stimulates the production of RBCs?

Answer 3

Erythropoietin (EPO)

EPO is produced by the kidneys and stimulates erythroid progenitors.

Question 4

Where does haematopoiesis primarily occur in adults?

Answer 4

• Bone marrow (pelvis, vertebrae, sternum)
• Spleen/liver (end-of-life clearance)

Haematopoiesis is the process of blood cell production.

Question 5

What are the three main types of blood vessels?

Answer 5

• Arteries
• Veins
• Capillaries

Each type has distinct structural characteristics and functions.

Question 6

What is the role of capillaries?

Answer 6

Exchange of substances

Capillaries have a thin endothelium and basement membrane for efficient exchange.

Question 7

What is the function of plasmin in the clotting process?

Answer 7

Degrades fibrin

Plasmin is involved in fibrinolysis, balancing clot formation.

Question 8

Define anaemia based on hemoglobin levels.

Answer 8

Hb ↓ (<120 g/L women, <140 g/L men); severe <70 g/L

Anaemia is characterized by low hemoglobin levels.

Question 9

What primarily stimulates erythropoietin (EPO) release and from where?

Answer 9

Tissue hypoxia sensed by the kidney (peritubular interstitial cells) → EPO release to drive erythropoiesis.

EPO is crucial for the production of red blood cells in response to low oxygen levels.

Question 10

Define Virchow’s triad and its relevance.

Answer 10

Stasis + endothelial injury + hypercoagulability → ↑risk of venous thrombosis (core framework for VTE risk assessment).

Virchow’s triad is fundamental in understanding the pathophysiology of thrombosis.