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Name of presentation by Mr X. Free Powerpoint Templates. CELLULAR AGING. WHAT IS A CELL. The cell is the basic structural and functional unit of all living Organism. CELLULAR AGING.
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Name of presentation by Mr X Free Powerpoint Templates
WHAT IS A CELL The cell is the basic structural and functional unit of all living Organism
CELLULAR AGING The decrease in the cell's ability to proliferate with the passing of time. Each cell is programmed for a certain number of cell divisions and at the end of that time proliferation halts. The cell enters a quiescent state after which it experiences CELL DEATH.
THEORIES OF AGING
BIOLOGICAL THEORIES > Evolutionary Theory: Aims to explain why almost all living things weaken and die with the age. >Telomere Theory:Shortened telomeres activate the mechanism that prevents further cell multiplication.
GENETIC THEORIES” > Accumulative Waste Theory: points to buildup of cells of waste products that presumably interferes with metabolism. > Wear and Tear Theory: idea that changes associated with ageing are the result of chance damage that accumulates over time.
> Error Accumulation Theory: ageing that results the damage to genetic coding.>Somatic Mutation Theory: ageing results from damage to genetic integrity of body’s cells.>Free Radical Theory: that free radicals, unstable organic molecules (generally oxygen spp.) give rise to ageing.
1. Cellular senescence: > Lifespan is regulated by genes. > Their functions gradually decline due to random errors in DNA replication leading to the accumulation of senescent cells.
Two possible pathways through which cellular senescence may contribute to the ageing process.
2. DNA damage: > a crucial mediator for cellular senescence. > oxidative DNA damage accumulates with age by an age-related increase in ROS production and a decline in DNA repair capacity.
3.Telomeres: > are the regions of DNA at the end of linear chromosomes. > are shortened during each cell division as DNA is replicated > telomere shortening is an indicator of aging at the DNA level. > Faster telomere shortening means faster aging.
Simplified diagram depicting the structure of the telomere and its location on the chromosome and in the cell Clinical Science (2011) 120, 427-440 - Haidong Zhu, Matthew Belcher and Pimvan�der�Harst
Cell loss • Nuclear mutations • Mitochondrial mutations • Cellular senescence • Extracellular cross-links • Extracellular junk • Intracellular junk
The process of aging is a net result of number of factors including:> Primary intrinsic process within the living body.> Life style of the individual.> Influence of the environment.> Diseases.
CARDIOVASCULAR SYSTEM > Deposits of the "aging pigment”, lipofuscin. > Heart rate diminished. > Valve stiffness. > Heart muscle cells degenerate. > Arteries become stiffer.
> Neurons of central and peripheral nervous system degenerate. > Nerve transmission slows.> Loss of motor coordination, intellectual function and short term memory. CENTRAL NERVOUS SYSTEM
> Pulmonary function decreases.>Number and size of alveoli decreases.> Vital capacity declines.> Reduction in respiratory fluid. RESPIRATORY SYSTEM
> Reduced GI secretions.>Reduced GI motility.>Decreased weight of liver.> Reduced regenerative capacity of liver.> Liver metabolizes less efficiently. GASTROINTESTINAL TRACT
> Progressive decrease in renal blood flow and glomerular filtration rate.> Size and number of nephrons decrease.> Less able to clear drugs from system.> Bladder muscles weaken. • RENAL SYSTEM
SENSE ORGANS. • > Loss of flexibility in the lens. • > Eyelids baggy and wrinkled. • > Difficult to hear high frequency • sound. • > Loss of taste buds.
INTEGUMENTARY SYSTEM • > Thinning of skin as collagen is • lost from epidermis. • > Loss of subcutaneous fat. • > Hairs turns grayer and thinner • due to loss of pigments. • > Nails become brittle and flake. • > Temperature regulation difficult.
OTHER EFFECTS • > Lean body mass decreases. • > Bone mineral content diminished. • > Decrease in height from narrow • vertebral spaces. • > Decline in immune function.
• Cataracts • Hearing Impairment • Osteoporosis • Osteoarthritis • Benign Prostatic Hyperplasia (BPH) AGE-DEPENDENT DISEASES
Vulnerability to Infections. • Alzheimer’s disease.• Parkinson’s disease.• Some cancers.• Calcific aortic stenosis.• Glaucoma.• Metabolic syndrome.• Atherosclerosis.• Hypertension.• Type II diabetes. AGE-RELATED DISEASES
Death by underlying or multiple cause, expressed in rates per 100,000 people, as a function of age for the year 2001 US population aged 85 and older Death by underlying or multiple cause, expressed in rates per 100,000 people, as a function of age for the year 2001 US population aged 85 and older
Eat a balanced diet with supplements. Don't smoke. Keep your mind and body active. Get regular checkups. Exercise: The anti-aging way, meditated yoga. Take daily action to deal with life’s challenges Get involved in your community. Spend time in nature. Get the sleep that your body needs.