exam deck 10

Question 1

What are the three main steps in haemostasis?

Answer 1

Vasoconstriction, Platelet Plug Formation, Clotting Cascade.

Question 2

Why is thrombin crucial in haemostasis?

Answer 2

It converts fibrinogen to fibrin, activates Factor XIII for clot stabilization, and promotes clot retraction.

Question 3

What role does von Willebrand Factor (vWF) play?

Answer 3

vWF mediates platelet adhesion to the damaged site.

Question 4

What substances are released by platelets to promote aggregation?

Answer 4

ADP, Thromboxane A2 (TXA2), and Serotonin (5-HT).

Question 5

What distinguishes the intrinsic and extrinsic pathways?

Answer 5

The intrinsic pathway is activated by internal vessel damage, while the extrinsic pathway is triggered by external trauma exposing tissue factor.

Question 6

What is the common endpoint of both pathways in the clotting cascade?

Answer 6

Activation of thrombin, which converts fibrinogen to fibrin.

Question 7

How does calcium contribute to clotting?

Answer 7

It facilitates the activation of clotting factors in the cascade.

Question 8

How is a clot stabilized after fibrin formation?

Answer 8

Factor XIIIa cross-links fibrin strands, and platelet actin and myosin retract the clot edges.

Question 9

What happens during clot retraction?

Answer 9

Platelet contraction reduces the wound size by drawing the edges together.

Question 10

What enzyme is responsible for clot breakdown in fibrinolysis?

Answer 10

Plasmin.

Question 10

How is plasmin formed?

Answer 10

Tissue plasminogen activator (t-PA) converts plasminogen to plasmin.

Question 11

What inhibits t-PA activity?

Answer 11

Plasmin Activator Inhibitor (PAI-1).

Question 12

Name two vasodilators released by intact endothelial cells.

Answer 12

Prostacyclin and Nitric Oxide (NO).

Question 13

How does heparin prevent clotting?

Answer 13

By activating antithrombin, which neutralizes clotting factors IX-XII.

Question 14

What is the role of thrombomodulin in anti-coagulation?

Answer 14

It binds thrombin, aiding Protein C and S in inactivating Factors V and VIII.

Question 15

What does Tissue Factor Pathway Inhibitor (TFPI) do?

Answer 15

Inhibits the Factor VII/tissue factor complex.

Question 16

How does aspirin affect haemostasis?

Answer 16

It inhibits thromboxane A2 synthesis, reducing platelet aggregation.

Question 17

What is the mechanism of action of warfarin?

Answer 17

It inhibits Vitamin K-dependent synthesis of clotting factors II, VII, IX, and X.

Question 17

What are the risks associated with aspirin and warfarin?

Answer 17

Increased bleeding time.

Question 18

What are the two arms of the immune system?

Answer 18

Innate and Adaptive immunity.

Question 19

How do innate immune cells recognize pathogens?

Answer 19

Through Pathogen-Associated Molecular Patterns (PAMPs) detected by Pattern Recognition Receptors (PRRs), like Toll-like receptors (TLRs).

Question 20

Name two key phagocytic cells.

Answer 20

Neutrophils and Macrophages.

Question 21

What is the function of the complement system?

Answer 21

Tagging pathogens (opsonization), recruiting immune cells, and lysing pathogens with the Membrane Attack Complex (MAC).

Question 22

What is the role of T helper cells (Th)?

Answer 22

They secrete cytokines to modulate immune responses and help B cells produce antibodies.

Question 23

What happens during the secondary immune response?

Answer 23

Memory B cells recognize the same pathogen, leading to a faster and stronger response.

Question 24

What are the main classes of antibodies?

Answer 24

IgM, IgG, IgA, IgE, and IgD.

Question 25

Which antibody is associated with mucosal immunity?

Answer 25

IgA.

Question 26

What is a cytokine storm?

Answer 26

A life-threatening overproduction of cytokines in response to infection.

Question 27

What triggers anaphylactic shock?

Answer 27

Mast cells releasing histamines and other mediators during an extreme allergic reaction.