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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

starnd of MRI and ?why
ruha Reply
what is haploid
Sonnie Reply
half of diploid(2n) n no of chromosomes I.e human have 46 no of chromosomes and its haploid is 23
Sayed
Half of diploid
ruha
exactly
Sayed
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ruha
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Sayed
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ruha
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2endyear
ruha
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Sayed
what are oxygen free radical
Fateemah Reply
are very reactive molecules that can react with every cellular component
Irene
is a molecule that contains atleast one unpaired electron
kevin
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hello
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what is anatomy
Ovbiagele Reply
is the study of structure of the body
Saifullah
is the study of the structure and function of the human body
Irene
can we put catheter in superficial circumflex iliac artery?
Sayed Reply
yes
Andrei
yes
Irene
yes
MONISH
what is anatomy
Eunice Reply
describe how penile erection occurs
Eunice
the study of the parts of an organism
Ayisi
is the study of the bones
Zainab
that's osteology
Ayisi
Ok
Emmanuel
How many hair do we have
Emmanuel
hair?
christine
why it's not advisable to not to give an intramuscular
Jamila Reply
well l think intramuscular injection takes a long time to get to the cells of the body for action whislt an intravenous injection goes straight to the heart and then pump to the cells /tissues quickly.So in a nutshell, intramuscular is slower and takes a longer time to work
Anna
it depends on the route of administration of drugs in an instance where the drugs to be given needs a fast action then intravenous is given but if opposite then intramuscular is advised
Deborah
Some times it is not fast in action, and again due to some complications of IM such as injection abcess, and pain.
Idris
why in IM ingestion should not be more than 2ml
Fatou
because of tissues inflammation the high dose of more than 2mls may cause
Clifford
TSH secretion is inhibited by stress and cortisol
Hadi Reply
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hi
Muhammad
Hello my friend. What do you want to chat about?
mehmet
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mehmet
why it's not advisable to not to give an intramuscular injection on the shoulder more than 2ml
Fatou
what are the factor that stimulates bile secretion
Linda Reply
secretin ,gestrin , glucagon, cholecytokinin-pancreozymin,
Leila
bile secretion is stimulate by secretin . bile secrete in to gall bladder .gall bladder store and concentrate bile...
Anoop
what happens to the rate of breathing during acidosis? why?
Rachael Reply
the breathing rate increases
Azapa
The breathing rate decreases due to accumalative amounts of carbondioxide. Or un balanced amounts of oxygen and carbondioxide
farouq
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explain on the cellular respiration
Racheal Reply
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Cleopatra Reply
The founder of anatomy is called herophilos
Thiep
is the study of the human body
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does blood moves through the heart
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LifeLine
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No 👎.
ring
Since dendrites are at the terminal end of a sensory neurone allowing it to transmit impulses to the relay neurone... what is at the other terminal end of the sensory neurone that connects it to the sensory organ?
Emmanuel Reply
The sensory organs have receptors which detect the stimulus then transmits impulses to the neurones via synaptic transmission. Meaning dendrites connect the sensory neurones to the receptors in the organ.
Cindah

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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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