PPT On CELLULAR AGING

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CELLULAR AGING Presentation Transcript:
1. CELLULAR AGING

2.WHAT IS A CELL
The cell is the basic structural and functional unit of all  living
Organism

3.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.

4.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.

5.> 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.

6.> 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.

7.MECHANISM OF CELLULAR AGING

8.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.

9.  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.

10.2. 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.

11.3.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.

12.Cell loss
Nuclear mutations
Mitochondrial mutations
Cellular senescence
Extracellular cross-links
Extracellular junk
Intracellular junk

13.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.

14.CARDIOVASCULAR SYSTEM
> Deposits of the "aging pigment”, lipofuscin.
> Heart rate diminished.
> Valve stiffness.
> Heart muscle cells degenerate.
> Arteries become stiffer.

15. > Neurons of central and peripheral               nervous system degenerate.  > Nerve transmission slows. > Loss of motor coordination, intellectual      function and short term memory.