Where does the heights, shape among other transformational bodily changes come from?

Hello fellow steemians,

Today, I decided to write on a topic I surprisingly discovered is vague to majority of people in our society, especially people in non-science related fields.

In life, there are a lot of things which are highly unstable. We are constantly in a race of transformation all through our lives. I remember when I went home for my last holiday from college. It had been six months since I last saw my family and seeing them again, I was amazed at the tremendous changes they had undergone. My younger brother had grown taller than me. He was already keeping a beard when I am still trying to grow one. And most of his friend too; all tall and recruited in the town's basketball team. And grandpa was growing more grey hair; he's already developing the wise old man's voice too. Thus, we can deduce that the only element of life which remains constant is change.

Many individual wonder at what exactly is responsible for these changes; where do they come from? How does the body tell how old it is? Where does the bone lengthening come from? How come the voice beging to deepen? How the body does even produces sound? The answer lies within the individual cells of the body.

The human body is a multicellular structure composed of diverse types of cells which are specialized for assorted activities and functions. All these cells with the exception of the red blood cells (RBC) is constituted of at least a nucleus. The major and most important constituent of the nucleus is the deoxyribonucleic acid (DNA). The nucleus hold the answer to the cell's lifespan, how it behaves and how it responds.

Living organisms work in a very similar manner like a computer system. A computer system is made up of hardware structures which is tangible- can be touched and felt. And also made up of the software, a set of basic instructions on how the hardware of the computer should act. Thus, it can simply be said that a computer system act based on instructions written by a programmer and will not do whatever instruction is not found in its software. These instructions in the case of the human body are found encoded within the DNA of every cell. These instructions contain the gender of a person, intended height, eye color, skin color, voice, physique among every other components of our appearance. The human body is able to achieve these characteristics by producing proteins and hormones.

The deoxyribonucleic (DNA) is a genetic macromolecule which stores genetic information and instructions. The DNA of an individual is inherited from both parents of the individual; this explains why we have similar physical resemblance to our parents. The deoxyribonucleic acid (DNA) provides instructions required for the production (synthesis) of proteins in the cell. Proteins as we all know are the building blocks of the body. The proteins that make up the skin are majorly filaggrin, keratin, elastin and proteoglycan. The protein that makes up the red blood cell is majorly hemoglobin. The principal proteins that make up the human hair are melanin and keratin. The principal protein in bone is collagen.

NB: Proteins are not the only substance the DNA encode for. Dipeptide, tripeptides and polyeptides are also included. Peptides (dipeptides, tripeptides, tetrapeptides, polypetides) and proteins are composed of monomeric units of amino acids. The difference lies in the number of amino acid contained in the molecule. An amino acid containing molecule can be called a protein only and if it contains more than 50 amino acids. A dipeptide is composed of two amino acids, a tripeptide contains three amino acids, a tetrapeptide contains four and a poly peptide contains twenty one amino acids and above.

Changes in the human body is simply a resultant of altering the amount, presence and quantity of body proteins (Nb: The body is also made up of additional substances other than proteins. Changes in the body is there by not secluded to proteins alone but also involves these substances). One of the changes that occur in the body is increase in weight. This can be as a result of increasing the body's lean body mass or increasing the body's fat tissues. The deposition of body fat depends on the gene (DNA) of the person alongside their diet.

The position of hormones in body changes

We have learnt briefly from above that changes in the body are due to the altering of the body protein. However, it is more complex than that: Hormones are also involved. Hormones are proteneous or polypeptide chemical substances/ molecules which are secreted by the endocrine (ductless) glands of the body. The endocrine glands are made up of specialized cells which synthsizes the hormones based on the instruction encoded in their DNA. Hormones are endocrine chemical messengers transported from their site of production (endocrine cells/glands) to their targeted organs/tissues. These hormones pass through the bloodstream to the targeted organs and tissues in which they are to effect changes.

How does an recognize an hormone? As hormones flow freely in the blood, they don't effect changes on all organ they come in contact with. They only effect changes in the organ that have a receptor for the hormone. If two different organs have the receptor for a particular hormone, the changes effected by the hormone are often different in the two organs. Hence, it is impossible for a hormone to cause lengthening of both the bone, kidney and brain.

Hormones help regulate physiological activities of the cells, help monitor blood parameters and as well- initiates bodily changes. Insulin and glycogan for example help monitor blood sugar level, erythropoietin initiates production of red blood cell, estrogen and progesterone aid in female secondary sexual characteristics, cortisols help in relieving stress, dopamine roles in rewards system and addiction and growth hormone work on growth. The activity of a hormone can be influenced by another hormone; the presence of an hormone can activate or inhibit the activities of another hormone.

How height increment works

^{Licence: Public domain :: Source: Wikimedia}
The major structure concerned when talking about heights are the muscles and bones (musculoskeletal system). Majority of the bones in the human body take many years to grow into maturity from the time of birth. Bones are specialized connective tissue made up of a matrix and different types of specialized cells. The matrix can be likened to a pool containing different cells (which in this case are the fishes). The major constituent of the bone matrix include the protein- collagen, deposited calcium phosphate (Ca₃(PO₄)₂)and calcium carbonate (CaCO₃).

The specialized cells that make up the human bones include: osteoblast, osteoclast and osteocytes. Osteoblastic cells are involved with bone formation. They are the major cells involved with the formation of bone matrix, synthesis of proteins and calcification which results in the lengthning of the bone. Their activities is stimulated by growth hormone, calcitonin, insulin, testosterone, eostrogen, skeletal growth factor, bone derived growth factor and vitamin D. These cells activities are however inhibited by the presence of the stress hormone- cortisol.

The osteocytes and osteoclast are incvoled with the maintenance of the bone as a living tissue. They help in exchanging of the bone calcium with the blood so as to maintain blood calcium level.

At initials, bones were mainly cartilages during embryonic development in the womb. Soon, calcium is deposited converting it to a hard structure known as bone. Many of the bones in the body do not completed get mineralised converted to bone (ossification) until later years. The area of a bone known as the epiphysis is the site at which further leghtning of the bone occurs. It is a part of long bones found seperately from the shaft and is covered with cartilage. When this part gets mineralised, the person looses the potential to increase in height.

Pubertal Changes

Puberty is a phase in a person's life whereby the rate of growth is expeditious and impressive. Throughout the course of this phase, there is a spectacular height growth (tallness), vocal changes, emotional development, production of gametes, sprouting of hair in difference places among other manifestations that transits a person from the stage of childhood into adulthood.

At a certain age which usually lies between the ages of 10 and 16, certain hormones are being secreted into and transported within the bloodstream. These secreted hormones cause the realease of even more hormones until there is a complex activity of diverse cascading hormones. At the onset of puberty, the first hormone in the line of initiating growth is the gonadotropin releasing hormone (GnRH). GnRH is secreted by the hypothalamus in the brain. This hormone on getting to the pituitary gland triggers the gland to secrete other hormones; leutenizing hormone (LH) and the follicle stimulating hormone (FSH). These newly secreted hormones then travel to initiate production of estrogen, progesterone and testosterone. The FSH and LS in male causes the testes to produce abundant testosterone and as well initiate sperm production. In the female, these hormones cause the production of gametes (eggs) in the ovaries and to as well produce progesterone and estrogen.

Many other hormones soon join in and cause breast development in girls, voice deepening, and muscle development in guys among many other characteristics that will surface.

Further reading:

• DNA and Proteins
• Puberty
• Hormone
• Growth and Development

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Thanks for reading through, I hope this post enlightened you on the basics of human growth and developments. All comments and upvotes will be appreciated, thank you!