The way the human body functions can be compared to a large chemical factory, where many individual biochemical processes are interlinked to function as a complete organism. These amazing biochemical processes are designed to create life, to grow, to heal, to repair, and is some cases, to create something new in a genesis-like way.
The word “genesis” was borrowed from Latin and derived from Ancient Greek, meaning origin, beginning. The Mirriam-Webster dictionary describes genesis as “the origin or coming into being of something”.
“Coming into being of something” also applies to some of the biochemical processes in the human body, where “-genesis” is used as a suffix to describe certain genesis-like processes in our bodies.
Genesis-like processes in our bodies:
The “coming into being” of the human body entails growth from a single cell to an adult human being. During the transition from the start of life up to the very end when death occurs, many genesis-like processes are continually taking place in our bodies.
Embryogenesis: After an egg has been fertilized and implanted in the uterus, the developing form is known as the embryo. Human life starts with the development and formation of the embryo, which is characterized by the processes of cell division (the division of a cell into two or more daughter cells with the same genetic material) and cellular differentiation (the process during which young, generalized cells take on individual characteristics and develop into their specialized form and function). This type of genesis occurs during the early stages in the development of the embryo.
Organogenesis: During the third to eighth week the organs begin to develop in the embryo and continue until birth. Full development of organs such as the lungs continues after birth. In the early developmental process, an embryo transforms from a one-dimensional layer of epithelial cells and reorganizes into a multilayered and multidimensional structure. This process is called gastrulation. The three layers formed during gastrulation are the ectoderm, endoderm, and mesoderm, from which the internal organs are formed at specific sites within the organism.
The most crucial organs develop during organogenesis. Tiny buds of tissue are in place and holds all the primitive cells which will differentiate into the wide range of cells, which are necessary to create all the organs in the body. By week five, buds of tissue are in place to form the limbs, the skeleton, the nervous system, the circulatory system, and the early developmental structures of the esophagus, stomach, intestine, liver, pancreas, blood vessels, blood cells, while the heart is already functioning.
Gametogenesis: The processes involved in the development of male sperm (spermatogenesis) and female eggs (oogenesis) are referred to as gametogenesis. Oogenesis in the female reproductive system refers to the growth process in which the primary egg cell, also known as an ovum, becomes a mature ovum. The fetal ovary begins germ cell development early in fetal life. By the time the female is born, all the egg cells (around 400 000) that the ovaries will release in her life are already present in the ovaries. During spermatogenesis, stem cells are deposited during gestation and remains inactive until the beginning of adolescence, when gonadotropic hormones from the anterior pituitary activate these cells and the production of sperm, which continues into old age.
Adipogenesis: Starting during late embryonic development and continuing in the mature human being, fat-laden cells – called adipocytes – develop from stem cells and accumulate as adipose tissue at various sites in the body. Adipose tissue is commonly known as body fat, while adipocytes are commonly known as fat cells, which are specialized in storing energy as fat. Interestingly, humans have a genetic survival programming to survive during famines, as fat accumulation when there is abundance of food helps survival during periods of food shortages. Hunter-gatherers in the pre-historic era did not have the so-called civilization diseases of modern man, such as obesity, caused by a continued abundance of food, particularly unhealthy processed foods.
Lipogenesis: While adipogenesis refers to the formation of fatty tissue, lipogenesis refers to biochemical production of fat and in particular the conversion of carbohydrate into fat, to be stored as a long-term source of energy. Lipogenesis is stimulated by a high carbohydrate diet and its effects are partly mediated by hormones, which can either inhibit (growth hormone, leptin) or stimulate (insulin) lipogenesis.
Angiogenesis: The growth of new blood vessels from pre-existing blood vessels is a normal process that takes place throughout life. It starts in utero (the vascular system is the first organ system to develop in the embryo) and continues into old age. Angiogenesis refers to the process by which new blood vessels are formed from pre-existing blood vessels, specifically the process by which new capillary blood vessels are formed from pre-existing ones. The term angiogenesis stems from the Greek words “angio”, which means blood, and “genesis”, which means beginning.
Angiogenesis is a vital function for growth and development, for the healing of wounds, and for a few days in every month in the female uterus, when the uterine lining is shed during the menstrual cycle.
However, angiogenesis can also play a role in several diseases and, for example, plays a critical role in the growth of cancer, as tumors need a constant supply of blood to grow and divide. Microscopically small cancers are formed in our bodies all the time, but remain dormant and small, unless they develop a blood supply. Some tumors can stimulate angiogenesis by activating growth factors that stimulate the formation of new blood vessels or by triggering nearby normal cells to release growth factors. When these new blood vessels are formed, the oxygen and nutrients they supply are used to feed the tumors, resulting in the tumor growing and cancer cells invading nearby tissue.
Neurogenesis: Conventional thinking amongst neuroscientists used to be that the brain cells you were born with were fixed for life. During the 1990’s, with the aid of more advanced technology, evidence of neural stem cells was found in certain areas in the brains of adults. As stem cells have the unique ability to transform into new cells through cell division, it means the brain can grow new brain cells, a process called neurogenesis. The term neurogenesis is made up of the words “neuro”, which relates to nerves or the nervous system, and the word “genesis”, which refers to the beginning of something. Neurogenesis therefore refers to the growth and development of new nerve cells in the brain, called neurons. A neuron is a specialized cell that transmits nerve impulses.
While neurogenesis is at its most active while a baby’s neurons are developing in the womb, scientists found that neural stem cells continue to form new neurons in two areas in the adult brain throughout life. Firstly in the dentate gyrus area in the hippocampus, which is an area that allows the brain to differentiate between different memories, such as where you have put your keys today as opposed to the day before. The hippocampus is the area in the brain associated with memory and learning. The second area where new brain cells are formed is in the subventricular zone in the brain, where for example newly formed neurons end up in the olfactory bulb, the center for the sense of smell.
Glycogenesis: The body breaks down carbohydrates from foods and converts them to the sugar called glucose, which is the main source of fuel for energy in the cells in our bodies. When blood glucose levels are sufficiently high to allow excess glucose to be stored, the stored form of glucose is made up of many connected glucose molecules (chains) called glycogen, and gets stored in liver and muscle cells. The biochemical formation of glycogen from glucose is referred to as glycogenesis.
Glycogen is the primary carbohydrate stored in liver and muscle cells and are broken down to release glucose into the bloodstream as fuel for cells when the body needs a quick boost in energy or experience a shortage of glucose from the diet.
Gluconeogenesis: To avoid low blood sugar levels (hypoglycemia) when glucose is not available, the human body can still produce energy to sustain life by either degrading the stored glycogen to create glucose (a process called glycogenolysis), or generate glucose from certain non-carbohydrate carbon substrates, a process called gluconeogenesis. These non-carbohydrate substrates include breakdown products of fats or proteins.
Gluconeogenesis occurs mainly in cells of the liver, but the cortex cells of the kidneys can also increase its relative contribution in diabetes and periods of prolonged fasting. When the body has excess energy available, gluconeogenesis is inhibited, and it gets activated when energy is required.
Ketogenesis: When carbohydrate stores in the body are significantly decreased, for example when fasting, an upregulation of the ketogenic pathway occurs with an increased production of ketone bodies, a process known as ketogenesis. During ketogenesis the liver converts fatty acids (either from the diet of from fat stored in the body) into ketone bodies. The ketone bodies then largely replace glucose as the chief source of energy for the body. Most organs – including the brain – and tissues can use ketone bodies as an alternative source of energy.
Pathogenesis: The process by which a disease or disorder develops is referred to as pathogenesis. The “patho” part of the word comes from the Greek “pathos”, which means “suffering, disease”, while “genesis” means “creation” in this context. Pathogenesis can include factors that contribute to the onset of a disease or disorder, the chain of events leading to that disease, as well as the progression and functional changes that accompany a particular syndrome or disease.
Conclusion:
While these summarized versions of the genesis-like biochemical processes taking place in our bodies do not reflect the intricate chemistry that is involved in each of these processes, they together and individually contribute to the “coming into being of something”,which sustains life.
References:
Organogenesis. Published online. Science Encyclopedia. J Rank Science and Philosophy. (www.science.jrank.org)
Lipogenesis. Published online and updated 19 February 2021. Biology Online. (www.biologyonline.com)
Adipogenesis. Published in Encyclopedia of Biological Chemistry (Second Edition), 2013. (www.sciencedirect.com)
Adipogenesis: A necessary but harmful strategy. Published in International Journal of Molecular Science. 2019 Aug: 20(15): 3657. (www.ncbi.nlm.nih.gov)
De Novo lipogenesis in health and disease. Published in Metabolism, Volume 63, Issue 7, July 2014, pages 895-902. (www.sciencedirect.com)
Gluconeogenesis. Published online and updated 4 July 2022. Chemistry. LibreTexts. (www.chem.libretexts.org)
Glycogenesis. Published online. Encyclopedia Britannica. (www.britannica.com)
Angiogenesis. Published online. Encyclopedia Britannica. (www.britannica.com)
Angiogenesis. Published in Brenner’s Encyclopedia of Genetics (Second Edition) 2013. (www.sciencedirect.com)
Human embryonic development. Information last edited 4 July 2022. Wikipedia. The Free Encyclopedia. (www.wikipedia.org)
Lipogenesis. Information last edited 6 June 2022. Wikipedia. The Free Encyclopedia. (www.wikipedia.org)
Adipogenesis. Information last edited 26 June 2022. Wikipedia. The Free Encyclopedia. (www.wikipedia.org)
Pathogenesis. Information last edited 22 May 2021. Wikipedia. The Free Encyclopedia. (www.wikipedia.org)
Glycogenesis. Information last edited 3 March 2022. Wikipedia. The Free Encyclopedia. (www.wikipedia.org)
Gluconeogenesis. Information last edited 20 May 2022. Wikipedia. The Free Encyclopedia. (www.wikipedia.org)
Angiogenesis. Published online. Blog. Health Insight. (www.healthinsight.co.za)
Neurogenesis. Published online. Blog. Health Insight. (www.healthinsight.co.za)
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