Question

question 1
in the extrinsic pathway of stage 1 of the clotting mechanism, chemicals released from damaged tissues trigger the cascade of events that ultimately result in the formation of
calcium.
vitamin k.
prothrombin activator.
fibrin.

question 2
the localized pressure gradient needed to maintain blood flow in a tissue is called
regional pressure.
perfusion pressure.
systolic pressure.
diastolic pressure.

question 3
the vagus is said to act as a \brake\ on the heart. this situation is called
cardiac inhibition.
coronary inhibition.
vagal inhibition.
autonomic inhibition.

Explanation:

• Question 1: In the extrinsic pathway of blood - clotting (stage 1), damaged tissues release chemicals that trigger the formation of prothrombin activator. Calcium is involved in the clotting process but is not the end - product of the extrinsic pathway trigger. Vitamin K is involved in the synthesis of clotting factors. Fibrin is formed in stage 3 of clotting (the common pathway after the formation of thrombin from prothrombin).
• Question 2: Perfusion pressure is the localized pressure gradient required to maintain blood flow in a tissue. Regional pressure is a more general term. Systolic pressure is the pressure during ventricular contraction, and diastolic pressure is the pressure during ventricular relaxation.
• Question 3: The vagus nerve (cranial nerve X) has an inhibitory effect on the heart, and this is called vagal inhibition. Cardiac inhibition is a very general term. Coronary inhibition would refer to inhibition of coronary arteries (not relevant here). Autonomic inhibition is too broad as the autonomic nervous system has both sympathetic and parasympathetic (vagus is parasympathetic) components.

Answer:

• Question 1: prothrombin activator
• Question 2: perfusion pressure
• Question 3: vagal inhibition