What are coronary arteries? what is sadness ?

Explanation:

Coronary arteries supply blood to the heart muscle. Like all other tissues in the body, the heart muscle needs oxygen-rich blood to function. Also, oxygen-depleted blood must be carried away. The coronary arteries wrap around the outside of the heart. Small branches dive into the heart muscle to bring it blood.

Sadness can be normal, and is only an indicator of underlying disease when feelings become excessive, all-consuming and interfere with daily living.

Coronary Arteries: The heart muscle is supplied with blood via coronary arteries. The heart muscle, like all other tissues in the body, need oxygen-rich blood to operate. Additionally, oxygen-depleted blood must be transported. The coronary arteries surround the heart on all sides. To supply blood to the heart muscle, little branches dive into it.

Sadness: Sadness refers to a wide variety of emotional states that humans can go through, ranging from modest disappointment to intense despair and pain.

✿   this landform has a high elevation and a high relief

✿   this landform is a mountain

stimulus is a change in the environment that causes an organism to react. the response is the reaction to the stimulus. some examples of stimuli for zebras are drought, to many predators, and bad feeding grounds such as dead grass or plants. zebras respond to stimuli just like all other living organisms