Physical Development
Pregnancy is divided into three trimesters and each trimester has different developmental mile stones for the fetus.
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3. Fetal Stage: Ninth week until birth. Embryo now known as a fetus. This stage is usually the longest and all the organs will be finished being created at the end of it.
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Birth
As soon as the baby is born, it is referred to as a neonate for the first month of life. Everything is so different outside of the womb. The first 24 hours of life is the most critical period; the first gasp of hair inflates the lungs and certain valves of the heart close off. The environment is much more harsh than the environment in the womb; it is colder, it has pathogens and many other dangers. The human body is such an amazing machine due to the fact that it adapts to such a world in such a short amount of time.
Infant physical development: infants follow distinct patterns of growth. One pattern is proximodistal (center of the body outward) and the other is cephalocaudal (top of the head downward). The baby is born with nearly perfect senses. All senses are perfect except their eyesight. Babies learn the world around them by touch, smell, hearing and eyesight.
Childhood development: This is defined as changes in height and weight and proportions of the body. Growth is rapid up until puberty. Every child grows at a different rate but there are still milestones that are expected to be reached at certain ages. There are certain patterns of growth that are looked at when talking about development: neural, somatic and reproductive.
Childhood development: This is defined as changes in height and weight and proportions of the body. Growth is rapid up until puberty. Every child grows at a different rate but there are still milestones that are expected to be reached at certain ages. There are certain patterns of growth that are looked at when talking about development: neural, somatic and reproductive.
- Neural growth: The brain is the most complex machine that the world has ever known to have existed; the growth of this organ is vital and it is measured by circumference and the unit is in centimeters. The most formative years for a child is the first five years.
- Somatic growth: The growth of the body. Children usually reach 40% of their adult height by the age of three. Girls will usually hit a growth spurt 2 years before boys do. This growth spurt can last up to three years; this is due to the steroids and hormones released with the onset of puberty.
- Reproductive growth: the growth of the reproductive organs and the formation of gametes. Females usually start earlier than boys do but puberty lasts longer for the boys.
Physical Aging
As we grow old, our bodies change in more ways than one. We start out as a single cell and we grow, divide and develop into this incredible masterpiece defined as a human. We go through life and with living comes aging. As we our bodies grow old, many different changes follow suit: skin loses elasticity, our senses deteriorate and our reactions/reflexes aren't as keen as they used to be. Although we still don't fully understand the brain and its aging process, it is certain that it is not due to neuron loss as once thought. The chemical messengers and makeup of the brain seem to slow down.
If you think about it, aging is not such a mystery. We start off as a cell. We are a single celled organism for 30 minutes of our lives until we divide. We divide that single cell into a billion trillion cells that specialize and differentiate. That same DNA that created us is duplicated an obscene amount of times. It is said that we have a whole new set of organs by the time we are 20 years old. That is why it is considered our "prime time" of life. However, making a copy of a copy of a copy doesn't always result in a clear picture. Have you ever made a copy of a picture and then copied it on a copy machine and repeated that process about 85 times? The result is a blurred picture... not the crystal clear picture that we started with. It applies to our DNA as well. That is why our skin isn't as elastic as it used to be, that is why our chemicals aren't the way they used to be or the reason why our organs aren't as efficient as they used to be. Eventually we run out of copies to make copies with and that brings upon death. It's quite simple, really. **
If you think about it, aging is not such a mystery. We start off as a cell. We are a single celled organism for 30 minutes of our lives until we divide. We divide that single cell into a billion trillion cells that specialize and differentiate. That same DNA that created us is duplicated an obscene amount of times. It is said that we have a whole new set of organs by the time we are 20 years old. That is why it is considered our "prime time" of life. However, making a copy of a copy of a copy doesn't always result in a clear picture. Have you ever made a copy of a picture and then copied it on a copy machine and repeated that process about 85 times? The result is a blurred picture... not the crystal clear picture that we started with. It applies to our DNA as well. That is why our skin isn't as elastic as it used to be, that is why our chemicals aren't the way they used to be or the reason why our organs aren't as efficient as they used to be. Eventually we run out of copies to make copies with and that brings upon death. It's quite simple, really. **
**Students thought.