Step 1: Understanding Vasodilators
Vasodilators are substances that widen blood vessels, reducing blood pressure.
Histamine plays a key role in immune response and vasodilation.
Step 2: Classification of Given Options
Histamine causes vasodilation and regulates stomach acid secretion.
Serotonin affects mood and blood clotting but is not a vasodilator.
Codeine is an opioid pain reliever.
Cimetidine is a histamine receptor
blocker.
Final Answer: Since histamine is the primary vasodilator, the correct answer is (A).
In Bohr model of hydrogen atom, if the difference between the radii of \( n^{th} \) and\( (n+1)^{th} \)orbits is equal to the radius of the \( (n-1)^{th} \) orbit, then the value of \( n \) is:
In the given cycle ABCDA, the heat required for an ideal monoatomic gas will be:
A particle is moving in a straight line. The variation of position $ x $ as a function of time $ t $ is given as:
$ x = t^3 - 6t^2 + 20t + 15 $.
The velocity of the body when its acceleration becomes zero is:
Evaluate the following limit: $ \lim_{n \to \infty} \prod_{r=3}^n \frac{r^3 - 8}{r^3 + 8} $.