Biological Aging: What, In A Biological Sense, Is Aging? (Term Paper Sample)

Biological Aging
 
Question 1: What, in a biological sense, is aging?
A) In a few sentences, define aging in humans.
Aging refers to the gradual changes in physiological processes as well as structure in humans with the passage of time, Senescence declines biological functions and reduces the body’s ability to cope with metabolic stress( Bilder,2016).
B) List four organ systems or biological processes in the human body that change with age, and briefly, describe the underlying biological causes of those changes. (20 sentences )
- The Skin
-Thymus
-Thyroid gland
-The bladder
Changes in physiological processes and structure with time may affect the normal functioning of cells, tissues, and organs. Senescence declines various biological functions as well reduces the body’s ability to adapt to metabolic stress. Inability to get rid of oxidative stress agents such as free radicals may make the body cells and organs susceptible to diseases like cancer. In the skin during senescence there’s loss of subcutaneous fat, hair follicles, and melanocytes, blood flow to the skin is also decreased thus reducing nerve ending sensitivity. As a result of this change, the skin loses some of its properties such as thermoregulation and pathogen barrier function. Loss of elasticity is also experienced leading to the formation of wrinkles. The elderly individual will be prone to pathogenic invasion and abnormal temperature changes. Thymus an organ in the immune system shrinks with time, The population of naïve T cells depends on the rate of formation in the thymus. Aging leads to involution of the thymus hence reducing the rate at which naïve T cells are produced. Memory T cell population therefore deteriorates and weaken with age; this explains why immunity declines with an increase in age. The size of the thyroid gland an organ in the endocrine system also reduces with age. A change in size of thyroid gland may lead to a change in metabolic processes. Morphological and physiological modifications in the thyroid gland may develop health complications. Thyroid disorder is common among the elderly. Change in metabolic processes either increase thyroxine levels above normal or reduces it below optimum. The bladder an organ in the urinary system is also affected by the process of senescence. It undergoes morphological changes, and its capacity is reduced by half in the elderly. That's why old men urinate frequently.
C) Is there a difference between the process of aging and diseases that occur more often in old age? Briefly, state why you have concluded this. Be specific. (20 sentences)
There’s no difference. The process of senescence is the etiology of these diseases hence the reason why they are associated with the elderly. A change in physiological and metabolic processes as a result of senescence might develop health complications. Aging in humans is associated with an increase in oxidative stress. Failure of the body cells to adapt to metabolic stress due to senescence increases the levels of reactive oxygen species in the body.ROS will attack the body’s macromolecules like DNA forming DNA adducts as well as lipids generating a chain of reaction known as lipid peroxidation.DNA, lipids and protein damage during senescence as a result of oxidative stress is the cause of many diseases associated with aging(Nimse & Pal, 2015).Involution of the thymus as a consequence of the process of aging leads to the etiology of autoimmune diseases. Senescence affects the immune system particularly the thymus. The thymus shrinks and T cells formation reduce hence the rate of T cells elimination exceeds the rate of formation. Loss of T regulatory cells may lead to the increase of autoimmune reactions as well as inflammation. Pro-inflammatory cytokines like tumor necrosis factor will facilitate inflammation (Howcroft et al., 2013). .Autoimmune disorders that are common among the elderly will occur. Disorders like Hashimoto’s thyroiditis, Rheumatoid Arthritis are examples of autoimmune and inflammation-related diseases associated with old age. Clots and plaque formation in the blood vessels due to senescence is another common disorder among the elderly. Cerebrovascular system disorder is characterized by the hardening of the arteries and loss of elasticity.The heart muscles reduce in size due to senescence.This leads to cardiopulmonary diseases a defect that is so common among the elderly.Nerve cells lose dendrites as they age.Biosignal processes are affected by these spontaneous changes. Cells, therefore, lose communication, and the sense of hearing and sight are greatly affected. It is evident that diseases that occur mostly during old age are as a result of time-related change in the body’s structure, physiological and metabolic processes.
D) At what age do the processes of aging begin?
Increase in biochemical and a genetic defect with time is believed to facilitate senescence. A spontaneous change in the genetic makeup of a human being with time modifies the metabolic process. Gene expression is altered, and the process of transcription and translation takes a new path. Expression of defective genes might result from the synthesis of defective proteins. Research has shown that aging begins when normal genes are gradually replaced with broken ones, accumulation of these defective genes increases senescence. This explains why metabolic processes are modified during senescence. Reproductive genes are replaced with broken ones, and hence fertility reduces with increase in senescence. Structures known as telomeres situated at the ends of a chromosome gradually becomes shorter with age signifying reduction in cell division. When it shortens to a critical length, cell division stops and the process of senescence starts. At 25 years old senescence begins, but it’s followed by subsequent cell division. With time the rate of senescence increases as the rate of cell division decreases. At 40 years of age aging in humans takes a new course and cell division stops. The new phase of senescence will affect teeth, heart, hair, bones, and sexuality. Bones weaken and decrease in size. Senescence also leads to behavioral and psychological changes.
Question 2: Why does aging occur?
Discuss two hypotheses on what causes the cells in our body to age. Include the scientific evidence supporting each hypothesis. Which hypothesis do you think is more likely to be correct, and why. Are these hypotheses necessarily mutually exclusive? (30 sentences)
There is an assumption that external forces and environmental pressures facilitate aging, cells and organs are exposed to this condition, and they are damaged, accumulation of damaged cells and organs triggers senescence. Another assumption is that senescence is genetically triggered and programmed. Two types of theory try to explain the process of senescence. That is damage based and programmed ideas. Damage based theory denotes that the accumulation of damaged bimolecular without their replacement facilitates aging and death. Cells and organs are subjected to external forces and pressures leading to their damage and cellular dysfunction. Accumulation of this damaged cells and organs initiates senescence and eventually death. Programmed theories, on the other hand, imply that aging is programmed in the genetic makeup of an invidual and the change in the gene expression system of the genome facilitates aging and death. In this theory, there is an assumption that internal molecular clock controls the rate of growth and development of an individual. Changes in the gene expression system are regulated by these internal molecular clocks. These spontaneous changes are programmed in the genetic makeup of an individual hence aging in this theory is genetically triggered. I think the programme theory of aging is more likely to be true. It’s more convincing to say that senescence is genetically programmed than to say that it’s triggered by external forces and pressures. Most damaged, abnormal proteins and cellular dysfunction processes are as a result of the change in the gene expression system spontaneously. Mutations regulated by internal molecular clocks of the genome are greater than the ones triggered by external environmental factors. Programmed theory of aging is, therefore, more sensible than damage theory of aging. These hypotheses are not mutually exclusive. Damage based approach also recognizes some aspects of genetics while programmed theory recognizes some aspects of environmental factors. Damage theory considers protective and defensive genes and their role in senescence. The programmed approach also considers that interaction of organs and cells with the environment may result in aging at some extent (Bengtson & Settersten Jr,2016).
Question 3: Is aging “inherited”?
Is there a genetic basis for aging? Explore the evidence and discuss whether a person’s genes can influence how rapidly they age. Give at least two pieces of evidence that suggest there is a genetic component to aging. (20 sentences)
Aging is determined by genetic factors like telomeres and the genome. The length of the telomeres structures found at the end of the chromosomes is shortened to a critical length, and senescence begins. They signify the end of cell division and the beginning of senescence. Any alteration of the gene expression system of an individual will also affect his or her senescence. The genome controls aging process. Inheritance of defective genes might lead to premature aging. Research has shown that aging is inherited. Transfer of defective genes from parents to offspring facilitates senescence. Mutations in mitochondrial DNA results in aging. Transfer of mutated mitochondrial genes from mother to offspring and their up-regulation enhances aging. When mutated mitochondrial genes ...