The phrase "my heart jumps up" in the poem's opening line is an example of a metaphor. The narrator's heart does not physically leap up since it is stuck within his body. However, he describes it as if it were leaping because that is how emotions are understood to function in speech. This description of emotion is common in poetry and literature more generally. Poets often wish to emphasize the intensity of emotion by comparing it to something else that is equally strong but which can be controlled rather than escaped from. In this case, the poet is saying that his own heart feels like it is leaping because it is overwhelmed by joy. A similar idea is expressed in "Lovely Lime Tree Road" by John Greenleaf Whittier where the poet compares the beating of his heart to the rushing of a waterfall. It is important to understand that although these descriptions of emotion may seem realistic at first glance, they are not meant to be taken literally. They are used instead to highlight certain qualities about feeling emotion. For example, the word "jumping" when used to describe someone's heart implies intense passion while "fluttering" suggests something weak and uncertain. In conclusion, a metaphor is a figure of speech in which one thing is used to describe another thing that is different yet has some connection with it.