PAT 201 ACTUAL EXAM PAPER 2026 UPDATED
PRACTICE QUESTIONS WITH FULL SOLUTION
GRADED A+
◉ 3 Plasma Protein Systems Answer: 1. COMPLEMENT SYSTEM
2. CLOTTING SYSTEM
3. KININ SYSTEM
◉ 1. COMPLEMENT SYSTEM Answer: - Can destroy pathogens
directly
- Activates or collaborates with other components of the
inflammatory response
- 3 pathways: Classic, Lectin, Alternative
◉ Functions of Complement System Answer: - Anaphylatoxic activity
resulting in mast cell degranulation
- Leukocyte chemotaxis
- Opsonization
- Cell lysis
◉ Classic Pathway Answer: Activated by antibodies and antigens
- C1 --> C3 (C3b has opsonin), C5 --> damage to bacterium
,◉ Opsonin Answer: Coats bacteria and makes it more susceptible to
phagocytosis
◉ Lectin Pathway Answer: Activated by MBL on pathogens
(mannose-binding lactin)
- via MBL and MASP complexes
◉ Alternative Pathway Answer: Activated by bacterial products;
endotoxins
◉ 2. CLOTTING (COAGULATION) SYSTEM Answer: - Forms a
fibrinous mesh at an injured or inflamed site
- Main substance and end product is fibrin, an insoluble protein
- Prevents spread of infection (keeps microorganisms/foreign
bodies at site of inflamm., forms a clot that stops bleeding, provides
framework for repair and healing
◉ Pathways of Clotting System Answer: Extrinsic
Intrinsic
◉ Extrinsic Pathway Answer: Tissue Factor F; endothelial vessel
walls
- is activated by tissue factor outside the vascular space
,◉ Intrinsic Pathway Answer: Sub-endothelial
- is activated in the vascular space when the vessel wall is damaged
◉ 3. KININ SYSTEM Answer: - Functions to activate and assist
inflammatory cells
- Primary product is bradykinin
- Kininase enzymes in plasma/tissues degrade kinins
◉ Kinin System Sequence Answer: Factor XII --> activation of
Prekallikrein --> converted to Kallikren --> acts on protein called
Kinogen and breaks it down --> BRADYKININ
◉ Bradykinin Effects Answer: - Vasodilation
- Pain
- Smooth muscle contraction
- Vascular permeability
- Leukocyte chemotaxis
◉ Control & Interactions of Plasma Protein Systems Answer: - 3
systems highly interactive
- Interactions among the 3 systems are finely regulated to: prevent
injury to host tissue; guarantee activation when needed
, - Multiple mechanisms are available to either activate or inactivate
(regulate) these plasma protein symptoms
◉ Carboxypeptidase Answer: Inhibits C3a and C5a
◉ Kininases Answer: Inhibits kinins
◉ Histaminase Answer: Inhibits histamine
◉ C1-esterase Inhibitor (C1-inh) Answer: Inhibits all 3 pathways
◉ Key Mediators of Inflammation Answer: Bradykinin
Complement
C Reactive Protein
Histamine
Leukotrienes
Prostaglandins
Tumour Necrosis Factor (TNF)
◉ Bradykinin Answer: The protein present in an inactive form in
plasma and mast cells
- broken down by an angiotensin-converting enzyme
PRACTICE QUESTIONS WITH FULL SOLUTION
GRADED A+
◉ 3 Plasma Protein Systems Answer: 1. COMPLEMENT SYSTEM
2. CLOTTING SYSTEM
3. KININ SYSTEM
◉ 1. COMPLEMENT SYSTEM Answer: - Can destroy pathogens
directly
- Activates or collaborates with other components of the
inflammatory response
- 3 pathways: Classic, Lectin, Alternative
◉ Functions of Complement System Answer: - Anaphylatoxic activity
resulting in mast cell degranulation
- Leukocyte chemotaxis
- Opsonization
- Cell lysis
◉ Classic Pathway Answer: Activated by antibodies and antigens
- C1 --> C3 (C3b has opsonin), C5 --> damage to bacterium
,◉ Opsonin Answer: Coats bacteria and makes it more susceptible to
phagocytosis
◉ Lectin Pathway Answer: Activated by MBL on pathogens
(mannose-binding lactin)
- via MBL and MASP complexes
◉ Alternative Pathway Answer: Activated by bacterial products;
endotoxins
◉ 2. CLOTTING (COAGULATION) SYSTEM Answer: - Forms a
fibrinous mesh at an injured or inflamed site
- Main substance and end product is fibrin, an insoluble protein
- Prevents spread of infection (keeps microorganisms/foreign
bodies at site of inflamm., forms a clot that stops bleeding, provides
framework for repair and healing
◉ Pathways of Clotting System Answer: Extrinsic
Intrinsic
◉ Extrinsic Pathway Answer: Tissue Factor F; endothelial vessel
walls
- is activated by tissue factor outside the vascular space
,◉ Intrinsic Pathway Answer: Sub-endothelial
- is activated in the vascular space when the vessel wall is damaged
◉ 3. KININ SYSTEM Answer: - Functions to activate and assist
inflammatory cells
- Primary product is bradykinin
- Kininase enzymes in plasma/tissues degrade kinins
◉ Kinin System Sequence Answer: Factor XII --> activation of
Prekallikrein --> converted to Kallikren --> acts on protein called
Kinogen and breaks it down --> BRADYKININ
◉ Bradykinin Effects Answer: - Vasodilation
- Pain
- Smooth muscle contraction
- Vascular permeability
- Leukocyte chemotaxis
◉ Control & Interactions of Plasma Protein Systems Answer: - 3
systems highly interactive
- Interactions among the 3 systems are finely regulated to: prevent
injury to host tissue; guarantee activation when needed
, - Multiple mechanisms are available to either activate or inactivate
(regulate) these plasma protein symptoms
◉ Carboxypeptidase Answer: Inhibits C3a and C5a
◉ Kininases Answer: Inhibits kinins
◉ Histaminase Answer: Inhibits histamine
◉ C1-esterase Inhibitor (C1-inh) Answer: Inhibits all 3 pathways
◉ Key Mediators of Inflammation Answer: Bradykinin
Complement
C Reactive Protein
Histamine
Leukotrienes
Prostaglandins
Tumour Necrosis Factor (TNF)
◉ Bradykinin Answer: The protein present in an inactive form in
plasma and mast cells
- broken down by an angiotensin-converting enzyme
