Skip to 0 minutes and 9 secondsNext I will talk about why the cell death take place? So you know everybody will hope go through the death. So there's a two theories to define why the cells death take place. Cells are genetically programmed to die lethal or senescence gene leads to cell death. So, that means you have the fate. That's mean eventually you will face to the cell death. The other theory for the reason why does the cell death take place? Cells eventually succumb to wear and tear intra or extra environmental deterioration causes cell death. That means because some of the body's functions disuse. For example your hormones, your neural transmitters so those very important substance are disuse. So eventually the cells face to death.
Skip to 1 minute and 28 secondsAnd what is the possible hypothesis for cell death? There's also two theories one as each organ independently loses its function and as a result, the body becomes senescence. So Hayflick proposed in 1965, he said that the growth potential of the cultured cells is inversely proportional to the donors age. That means the organ can be independently lose its functions. And finally the body loses whole functions. The other theory is deterioration of the supervising organs such as the central nervous system will cause the regression of other organs, except for the supervising organs such as central nerve sustenance. What kind of the supervising organ you would think about is also of the very important organ to guide the cell death.
Skip to 2 minutes and 38 secondsI will say not only the central nervous system, but also your immune system. The growth potential of a living organ is affected by its environment, which is possible under the control of supervising organ. So you can see environment can affect your supervising organ. So what is the supervising organ? You can face the challenge of the environment. You can see this immune system. So except for the central nervous system also the immune system we call those are supervising organ. However, the supervising organ will be deteriorated as you grow or as the age become growing and growing. So you can see the the brain shrinks with aging especially above 65 years old.
Skip to 3 minutes and 43 secondsThe possible of physiological changes with the your aging, you can see overall the breakdown of steady state, we call the breakdown of homeostasis. So with increased age you will see the homeostasis capacity is decreased. That means, that indicated decrease in synthesis and increase in degradation. Especially for those neurotransmitters such as acetylcholine and hormones levels So you can see with increased age those hormones, those neurotransmitters are a decreased and cannot keep the constant body temperature or blood sugar levels so with increased age, you also can see the breakdown of homeostasis the body temperature and the homeostasis of blood glucose.
Skip to 4 minutes and 47 secondsAlso that because of decreasing immunelogical capacity you will see the structure change especially for the atrophy of the thymus so the size of thymus will shrink with increased age, except for the the brain, the immune system may also be one of the supervising organ I just mentioned above. What are the counters of aging? We also talk about the breakdown of the homeostasis. So you can see increase degradation over decrease synthesis. So the shink are also you can see the shrinkage of the muscle fibers that's because of loss of the proteins. So because of loss of proteins, you shrink of your muscle fibers, you will decrease your muscle strength, you can also see your bone matrix is lost as well.
Skip to 5 minutes and 55 secondsThe content of matrix and the minerals especially Calcium, phosphorus are decrease with increased age. That willcost decreases in bone density except for decreasing muscle strength decreases the in bone density but unfortunately you will increase in the percentage of body fat. That means you change your composition of your bodies especially increased percentage of body fat but decrease in percentage the body water and decreased percentages in body proteins and also you will see lots of changes in many organs and also many functions. For examples, decrease in respiratory functions, decreased mobility and ambulatory capacity, decreased production of neurotransmitters. For example dopamine, serotonin, acetylcholine, those are very important new neurotransmitters for your emotion or for your heart rate ending and so on.
Possible hypotheses of cell death
Supervising organ regression and environment damage might be important factor causing cell death.
In this video, Prof. Chao will explain what is “cell death” and the hypotheses and some characteristics of aging.