“The heart is complex” Essay By Hayden Kelly 11/30/17 From whale hearts to humming bird hearts

“The heart is complex” Essay
By Hayden Kelly

From whale hearts to humming bird hearts, they all play a huge role in keeping something alive. Take a flea for example. A flea has a working brain, heart, digestive system, lungs, and much more. The fact that something as tiny as a pinhead can have fully functional organs and a reproductive system just shows how far evolution has gone.
The heart is very complex. In Joyas Voladoras, Brian Doyle talks about the many different types of hearts. “The biggest heart in the world is inside the blue whale. It weighs more than seven tons. It’s as big as a room. It is a room, with four chambers (L. 61-63).” In this quote, Brian Doyle is giving just one of the many examples of how complex the heart is.
The heart functions as the body’s circulatory pump. It takes in deoxygenated blood through the veins and delivers it to the lungs for oxygenation. It then pumps it into the various arteries which provide oxygen and nutrients to body tissues by transporting the blood throughout the body.
“Mammals and birds have hearts with four chambers. Reptiles and turtles have hearts with three chambers. Fish have hearts with two chambers. Insects and mollusks have hearts with one chamber. Worms have hearts with one chamber, although they may have as many as eleven single-chambered hearts. Unicellular bacteria have no hearts at all; but even they have fluid eternally in motion, washing from one side of the cell to the other, swirling and whirling. No living being is without interior liquid motion.
Invertebrate animals have very simple circulatory systems. Many do not have a heart or blood because they are not complex enough to need a way to get nutrients to their body. Their cells are able to just absorb nutrients through their skin.
Over billions of years, the heart has been modified and perfected. Joyas Voladoras is just one example.