As humans, we have receptors for two kinds of beta adrenergic compounds such as catecholamines. Cardiac muscle cells have beta 1 receptors that promote increased heart rate. Some drugs that slow heart rate are called beta blockers. Smooth muscle cells, however, have beta 2 receptors which mediate smooth muscle contractions. Blockers of these effects are sometimes used to treat asthma.

The description above illustrates what?

just because a drug acts on one type of receptor does not mean that it will act on another type.

Explanation:

Based on the scenario being described within the question it can be said that this description best illustrates that just because a drug acts on one type of receptor does not mean that it will act on another type. That is because there are a variety of different receptors each of which target different areas and have different functions, therefore a drug that performs a specific function cannot be used on all receptors.

you know that this symptom is misleading and quite often is related to: heart attack

a heart attack is a condition that occurs when the blood flow that transports oxygen to the heart muscle is damaged or cut off completely. the coronary arteries that supply the heart muscle with blood flow can be blocked by the accumulation of plaque. also, when the plaque within the heart artery breaks, it creates blood clot that can also hinder the blood flow. men that are over 45years of age and women that are over 55years of age are at risk of having a heart attack. the symptoms of a heart attack include chest discomfort, chest pain, coughing, and shortness of breath.