Which form of cellular adaptation occurs because of decreased work demands on the cell?
Which form of cellular adaptation occurs because of decreased work demands
on the cell? Explain your answer in a paragraph with at least 1 reference in APA format within the last five years published. No plagiarism please.
This section discusses cellular effects, but cell and chemical effects cannot be easily separated because cells are made up of a wide range of chemicals. Changes in the cell’s appearance or function may result in specific intracellular chemical changes. The mechanisms that cause cell damage are typically biochemical in nature.
Explanation of Adaptation
Cells and tissues must maintain homeostasis in order to function properly.
“Compensate” for new demands by constantly adapting to changes in the tissue environment.
Are usually capable of incredible cellular adaptability.
Adapt in a way that may be beneficial or harmful in nature (physiological) (pathological).
Physiological adaptation examples include:
Increased skeletal muscle cell count in athletes as a result of exercise and increased metabolic demand.
The increase in the number and size of epithelial cells in women’s breasts caused by endocrine stimulation during pregnancy.
When these cells or tissues are damaged, the body attempts to adapt and repair the damage or limit the negative consequences. Adaptive changes frequently result in cells or organs that cannot function normally. This is a pathological change caused by imperfect adaptation.
Pathological adaptations include:
Cellular changes in cigarette smokers: Cigarette smokers’ trachea and bronchi have ciliated columnar epithelium that has changed to non-ciliated squamous epithelium. Squamous epithelium replacement can better withstand cigarette smoke irritation. The loss of cilia and mucous secretions of columnar epithelium, on the other hand, weakens the tracheobronchial defense mechanisms.
Cirrhosis of the liver is caused by the replacement of normal liver cells by fibrotic cells in chronic alcoholics. A severely cirrhotic liver is incapable of normal metabolism, nutrition maintenance, and xenobiotic detoxification.
If the modification is minor, cellular adaptation may occur, and the cells will return to normal. When the damage is severe, it can result in cell death or permanent functional incapacity.
There are three types of cellular adaptation to toxic agents:
Cellular activity has increased.
Cell activity has decreased.
Cell morphology (structure and appearance) or cell function changes.
Cellular Adaptations of Various Types
Cell atrophy refers to a reduction in cell size. If a sufficient number of cells are involved, the tissue or organ may shrink in size as well. When cells atrophy, they have the following characteristics:
Reduced oxygen requirements.
Protein synthesis has been reduced.
Reduced the number and size of organelles.
The most common causes of atrophy are decreased cell use, a lack of hormonal or nerve stimulation, a reduction in nutrition, a decrease in blood flow to the tissue, and natural aging.
Atrophy is characterized by a decrease in the size of muscles and muscle cells in people whose legs are paralyzed, in a cast, or used infrequently, such as when a patient is on bedrest.
Individual cell size increases due to hypertrophy. This frequently results in the expansion of a tissue or organ. When cells hypertrophy, the number of cell components increases, as does their functional capacity to meet increased cell needs. Hypertrophy typically occurs when an organ or tissue is unable to adapt to increased demand by forming more cells. This is most common in cardiac and skeletal muscle cells, which do not divide to form new cells. Increased work or stress placed on an organ, as well as hormonal stimulation, are common causes of hypertrophy.
A compensatory increase in the size of cells in one kidney after the other kidney has been removed or is diseased is an example of hypertrophy.
Hyperplasia is characterized by an increase in the number of cells in a tissue. This usually results in an increase in tissue mass and organ size. It only occurs in mitosis-capable tissues such as skin, intestine, and gland epithelium. Some cells, such as nerve and muscle cells, do not divide and thus cannot undergo hyperplasia. Hyperplasia is frequently used as a compensatory measure to meet increased body demands. Hyperplasia is a common response to toxic agents and tissue damage such as wounds or trauma. Hyperplasia of connective tissue (for example, fibroblasts and blood vessels) contributes to wound healing. When the toxic stress is removed, the tissue often returns to normal. Hyperplasia can be caused by hormonal stimulation, such as increased estrogen production during pregnancy, which causes breast and uterine enlargement.
The conversion of one type of mature cell to another type of mature cell is known as metaplasia. It is a process of cellular replacement. Chronic irritation and inflammation frequently trigger a metaplastic response. This results in a more resistant tissue to external stress because the replacement cells can survive in conditions where the original cell type could not. However, cellular changes typically result in a loss of function that was previously performed by the original cells that were lost and replaced.
Here are some examples of metaplasia:
The most common condition in which a person experiences chronic acid reflux from the stomach into the esophagus (Gastroesophageal Reflux Disease). Normal esophageal cells (squamous epithelium) die as a result of acid reflux. They are replaced by columnar cells of the stomach, which are resistant to the acidity of the stomach. The medical term for this condition is “Barrett’s Esophagus.”
The transition of ciliated columnar epithelium to non-ciliated stratified squamous epithelium in the cells of the trachea and bronchi of chronic cigarette smokers. Metaplasia sites are frequently the sites of neoplastic transformations. The replacement cells lack the cilia’s defense mechanism for moving particles up and out of the trachea.
Cirrhosis of the liver, a common condition in chronic alcoholics, replaces normal functional hepatic cells with nonfunctional fibrous tissue.
Dysplasia is a condition characterized by abnormal cell changes or deranged cell growth in which the cells’ size, shape, and appearance differ from the original cell type. Cellular organelles become abnormal as well. The nuclei of dysplastic cells are larger than normal, and the mitotic rate of the dysplastic cells is higher than that of the precursor normal cells. Dysplasia is caused by chronic irritation and infection. In many cases, removing the stress and reintroducing normal cells can reverse the dysplasia. In other cases, dysplasia may be permanent or a precursor to cancer.
Atypical cervical cells, which precede cervical cancer, are an example of dysplasia. Cervical cell examination is a routine screening test for dysplasia and possible early stage cervical cancer (Papanicolaou test).
Cancer develops at the site of Barrett’s syndrome and in chronic smokers’ bronchi (bronchogenic squamous cell carcinoma).
Undifferentiated cells are referred to as anaplasia. They have irregular nuclei and a cell structure that is filled with mitotic figures. Anaplasia is frequently associated with cancer and is one criterion for determining a cancer’s aggressiveness. An anaplastic carcinoma, for example, is one in which the cell appearance has changed from the highly differentiated cell of origin to a cell type lacking the original cell’s normal characteristics. Anaplastic cells, in general, have lost the normal cellular controls that regulate division and differentiation.
Neoplasia is a new tissue growth that is commonly referred to as a tumor. Neoplasia is classified into two types: benign and malignant. Cancers are malignant neoplasia. Because cancer is such a significant and complex medical issue, it has its own section.
Interactions between two or more toxic agents can cause damage through chemical-chemical interactions, chemical-receptor interactions, or modification of the cell and tissue response to a second agent by a first agent. Interactions can occur if the two agents are exposed at the same time or if they are exposed at different times.
Chemical-chemical interactions have primarily been studied in the toxicology of air pollutants, where it has been demonstrated that the harmful effects of certain oxidants may be exacerbated in the presence of other aerosols.
In isolated perfused lung experiments, interactions at the receptor site were discovered. Pre-exposure to one concentration of oxygen, for example, may mitigate later exposure to 100% oxygen by modifying the cellular and enzymatic composition of the lung.
In mice, damage to the alveolar zone by the antioxidant butylated hydroxytoluene (BHT) can be greatly exacerbated by subsequent exposure to oxygen concentrations that would otherwise have little or no discernible effect.