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As exterior signs of aging increase, so do the interior signs, which are not as noticeable. The incidence of heart diseases, respiratory syndromes, and type 2 diabetes increases with age, though these are not necessarily age-dependent effects. Wound healing is slower in the elderly, accompanied by a higher frequency of infection as the capacity of the immune system to fend off pathogen declines.

Aging is also apparent at the cellular level because all cells experience changes with aging. Telomeres, regions of the chromosomes necessary for cell division, shorten each time cells divide. As they do, cells are less able to divide and regenerate. Because of alterations in cell membranes, transport of oxygen and nutrients into the cell and removal of carbon dioxide and waste products from the cell are not as efficient in the elderly. Cells may begin to function abnormally, which may lead to diseases associated with aging, including arthritis, memory issues, and some cancers.

The progressive impact of aging on the body varies considerably among individuals, but Studies indicate, however, that exercise and healthy lifestyle choices can slow down the deterioration of the body that comes with old age.

Homeostatic imbalances

Tissues and cancer

Cancer is a generic term for many diseases in which cells escape regulatory signals. Uncontrolled growth, invasion into adjacent tissues, and colonization of other organs, if not treated early enough, are its hallmarks. Health suffers when tumors “rob” blood supply from the “normal” organs.

A mutation is defined as a permanent change in the DNA of a cell. Epigenetic modifications, changes that do not affect the code of the DNA but alter how the DNA is decoded, are also known to generate abnormal cells. Alterations in the genetic material may be caused by environmental agents, infectious agents, or errors in the replication of DNA that accumulate with age. Many mutations do not cause any noticeable change in the functions of a cell. However, if the modification affects key proteins that have an impact on the cell’s ability to proliferate in an orderly fashion, the cell starts to divide abnormally. As changes in cells accumulate, they lose their ability to form regular tissues. A tumor, a mass of cells displaying abnormal architecture, forms in the tissue. Many tumors are benign, meaning they do not metastasize nor cause disease. A tumor becomes malignant, or cancerous, when it breaches the confines of its tissue, promotes angiogenesis, attracts the growth of capillaries, and metastasizes to other organs ( [link] ). The specific names of cancers reflect the tissue of origin. Cancers derived from epithelial cells are referred to as carcinomas. Cancer in myeloid tissue or blood cells form myelomas. Leukemias are cancers of white blood cells, whereas sarcomas derive from connective tissue. Cells in tumors differ both in structure and function. Some cells, called cancer stem cells, appear to be a subtype of cell responsible for uncontrolled growth. Recent research shows that contrary to what was previously assumed, tumors are not disorganized masses of cells, but have their own structures.

Development of cancer

This series of three diagrams shows the development of cancer in epithelial cells. In all three diagrams, layers of epithelial tissue cover a generic underlying tissue. In the first diagram, an injury kills a section of the epithelial cells. In the second image, new epithelial cells have completely filled in the wounded area. However, cell division is still accelerating. In the lowest diagram, the epithelial cells have continued to divide and have now expanded beyond the original wound area. The group of dividing cells, now called a carcinoma, breaks into the layer of underlying tissue.
Note the change in cell size, nucleus size, and organization in the tissue.

Watch this video to learn more about tumors. What is a tumor?

Cancer treatments vary depending on the disease’s type and stage. Traditional approaches, including surgery, radiation, chemotherapy, and hormonal therapy, aim to remove or kill rapidly dividing cancer cells, but these strategies have their limitations. Depending on a tumor’s location, for example, cancer surgeons may be unable to remove it. Radiation and chemotherapy are difficult, and it is often impossible to target only the cancer cells. The treatments inevitably destroy healthy tissue as well. To address this, researchers are working on pharmaceuticals that can target specific proteins implicated in cancer-associated molecular pathways.

Chapter review

Inflammation is the classic response of the body to injury and follows a common sequence of events. The area is red, feels warm to the touch, swells, and is painful. Injured cells, mast cells, and resident macrophages release chemical signals that cause vasodilation and fluid leakage in the surrounding tissue. The repair phase includes blood clotting, followed by regeneration of tissue as fibroblasts deposit collagen. Some tissues regenerate more readily than others. Epithelial and connective tissues replace damaged or dead cells from a supply of adult stem cells. Muscle and nervous tissues undergo either slow regeneration or do not repair at all.

Age affects all the tissues and organs of the body. Damaged cells do not regenerate as rapidly as in younger people. Perception of sensation and effectiveness of response are lost in the nervous system. Muscles atrophy, and bones lose mass and become brittle. Collagen decreases in some connective tissue, and joints stiffen.

Watch this video to see a hand heal. Over what period of time do you think these images were taken?

Approximately one month.

Got questions? Get instant answers now!

Watch this video to learn more about tumors. What is a tumor?

A mass of cancer cells that continue to grow and divide.

Got questions? Get instant answers now!

References

Emerson, RW. Old age. Atlantic. 1862 [cited 2012 Dec 4]; 9(51):134–140.

Questions & Answers

the diagram of the respiratory system
Praise Reply
Describe sinus of brain
MAHESH Reply
name the 5 layers of skin
Monika Reply
stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum
airiz
those are the layers of epidermis,, then we have the dermis which has got two layers that is papillary dermis and reticular dermis.. beneath the dermis we have the hypodermis( subcutaneous layer) which is not considered as a layer of skin
airiz
what's a feedback
ivhil Reply
is the information or comment about something that one have done
Gaston
may be you mean negative or positive feedback mechanism... in general, they mean body response its changes by hormones
Quran
what is endocrin?
Asim Reply
why should there be an inhibition to the process of gastric production in the intestinal phase
Gloria
endocrine is a system through which the secretions of cell directly poured into blood.
Tanveer
why should there be an inhibition to the process of gastric production in the intestinal
Gloria Reply
what is a stimuli
Emily Reply
environment factor that cause a cell to respond
Quran
name the two types of melanin
Laila Reply
deference between RNA and DNA
Ali
.DNA stands for Deoxyribonucleic Acid. The sugar portion of DNA is 2-Deoxyribose.RNA stands for Ribonucleic Acid.  The sugar portion of RNA is Ribose.2.The helix geometry of DNA is of B-Form (A or Z also present).The helix geometry of RNA is of A-Form.3.DNA is a double-stranded molecule consisting o
ryaisha
DNA consists of nucleotide but RNA consists of nucleoside DNA is double standard but RNA is single standard.In DNA at the nitrogen bases adinine,guanine,cytocin and thymine is present but in case of RNA instead of thymine uracil is present.
Tanveer
what are rdna
Budumari
what is a heart
walker Reply
A heart is an organ in the circulatory system that pumps blood throughout the systemic regions
bernard
what is anatomy
Aisha
Anatomy is the study of internal and external structures and the relationship among body parts. (the study of structure).
Tomi
what is the physiology of the heart
nadine
guys help me with a pathophysiology of asthma
Luyando
asthma is a lungs related disorder in which there is difficulty in breathing due to some allergic factors, their is inflamation of alveoli of respiratory part of lungs.also decreases the surface area.
Tanveer
what is meaning of brain strock and its types?
Tanveer
the pathophysiology of asthma is complex and involves airway inflammation and bronchial hyperresponsiveness pathogenesis of asthma
Omkar
skin infection please explain
Hamza Reply
what is malignant melanoma
Akon Reply
cancerous cells 🙄
Sohan
yes benign is non-cancerous malignant is cancerous.
Joseph
that's a simple way of explaining it however you're different processes like mitosis etc a person can be at risk for developing cancer etc
Joseph
you can tell by an unusual growth of a mole, or change in size coloration with melanoma. which is abnormal growth of your squamous cells.
Joseph
Types of wandering connective tissues
Hassan Reply
what are the meaning of skin
PASHALINA Reply
study of external structure of human body is known as anatomy
VINAY Reply
what is Tau?
Vicki Reply

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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