As most likely any student, professor, researcher, or doctor can tell you, the biological systems within the human body are far from simple. On every level of human anatomy, there is a complex arrangement of processes occurring simultaneously in order to maintain what we might consider to be everyday life.

Let’s take a look at one of the most recognizably significant parts of human life – the heart. The heart is a major component in the circulatory system, as it works to deliver oxygen and important nutrients to the body tissues, while cleaning out carbon dioxide and waste products.[1] Without the heart beating, there is no life. However, it is not as simple as one heartbeat. Within the heart there are the atria and the ventricles, which make up the two upper and lower chambers, respectively. There is also a dual-walled encasing, namely, the pericardium, that envelops the heart for protection. Pericardial fluid flows between the two walls of the pericardium, and ensures that the heart is properly lubricated with each contraction and interaction with the lungs. Underneath the pericardium, there is the myocardium and the endocardium. The former works to contract the muscle while the latter is in contact with the blood pumping through the heart. The atria and the ventricles are connected via the atrioventricular valves, both of which have their own separate function in regards to separating the ventricles from the pulmonary artery and the aorta. These valves are connected to the heart muscles via the heartstrings.

As if the various valves and structural components of the heart were not enough to demonstrate complexity, on a cellular level there is even more occurring. Within the heart alone there are atrial and ventricular cardiomyocytes, cardial fibroblast cells, endothelial cells, smooth muscle cells, and pacemaker cells.[2] Each of these cells has its own unique shape and contributes to the structure and function of the aforementioned components of the heart. Altogether, there are approximately ten billion cells making up the heart, including both connective tissue and heart muscle.[3] Each of these cells contains a membrane, a nucleus, a nucleolus, cytoplasm, and cytoplasmic organelles such as mitochondrion, lysosomes, and the endoplasmic reticulum, which all contribute to overall cell function.[4] The nucleus itself, contains DNA, an arrangement of nucleotide bases and amino acids whose specific order determines how exactly the cell will function and how it will be structured. Proteins work throughout the cell in various functions and are made up of twenty different amino acids. The order of amino acids that make up a protein determines how the protein will fold and ultimately what it will do.[5]

Four chambers, ten billion cells, and countless proteins make up only one muscle in the body. There is constant activity within each of these occurring for every single heartbeat. Even the smallest error within this overall system can cause chaos. In a recent experiment, it was analyzed how even the tiniest change to one amino acid in a protein chain can alter the entire protein’s function in a bacterial cell. From this experiment, the scientists concluded that “individual proteins are not isolated components – they are integral parts of a larger cellular system with multiple layers of interlocking genetic and physiological networks.”[6]

This observation and other studies on this subject often lead to the argument of “intelligent design,” a theory that became largely popular in the 1980s and has been discussed in great detail in books like Darwin’s Black Box by Michael Behe and The Design Inference by William Dembski. Essentially, the theory of intelligent design argues that the incredibly complex nature of human biological structures is a direct demonstration of God’s work.[7] While this theory has been both supported and refuted over the years by various scientists and researchers alike, one main takeaway from the complexity of human nature that has been overlooked is that everything in the human anatomical structure, and in all forms of life, has a specific function and purpose. The significance here is not the why, but rather the how – simply put, the way in which every part of our own bodies contributes to life as we know it mirrors how each of us, as individuals, has a role to play in God’s larger plan.

If every single cell in our heart works toward its being able to function, and ultimately toward our being able to continue living, then certainly we as humans have our own essential purpose in a larger goal. It says in Romans 8:28, “And we know that in all things God works for the good of those who love him, who have been called according to his purpose.”

More importantly, it is worth noting that the purposes of each cell, each structure, within the body are distinct. One cell cannot do what another can, the heart cannot perform the same functions as the lungs, the cell membrane cannot contain DNA in the same way the nucleus does. This holds true in life – each of us has a distinct purpose and role. It can be easy to become discouraged by another person’s skill in a certain area, but worry is unnecessary, as God has already determined how each individual has his or her own specialty in which he or she can contribute. Whether you are a determined public speaker, a dedicated researcher, or a talented musician, there is a role for you. And just as each individual cell’s success is vital for the function of the entire body, so are you to God’s ultimate plan.

We may not always be able to see the larger picture. Take a singular amino acid within a protein in one of the billions of cells, for example. Does it realize that it contributes to the function of the cell? Or to the organ it is a part of? Or to the system in which that organ operates? Or to the human body? Sometimes, it is easy to feel as if your life has no distinct purpose or that you are not contributing enough. But God sees the whole picture, and one day you will too, as we all work within a larger body – the body of Christ.

Marinna Okawa ’20 is a Human Developmental and Regenerative Biology concentrator in Dunster House and is a staff writer and design editor for the Ichthus.

[1]Lewis, Tanya. “Human Heart: Anatomy, Function, and Facts”. 22 March 2016.

[2]Xin, Mei, Eric N. Olson, et al. from Mending broken hearts: cardiac development as a basis for adult heart regeneration and repair. Nature Reviews: Molecular Cell Biology 14: 529–541 (2013).

[3]Bianconi. “An estimation of the number of cells in the human body. “Annals of the Human Body. 40.6: 463-471 (2013).

[4]NIH. National Cancer Institute: SEERTraining Modules: Cell Structure.

[5]Tomkins, J. Engineered Protein “Evolution” Proves Bio- logical Complexity. Acts & Facts. 42.3: 13-15. (2013).


[7]National Center for Science Education. “What is ‘ Intelligent Design’ Creationism?” 17 Oct 2008.

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