Summary
Declining stem cell function, accumulating damage and reduced repair gradually lower organ capacity.
In depth
Changes include loss of muscle mass (sarcopenia), reduced bone density, stiff arteries, reduced kidney function and slower reflexes. Mechanisms: telomere shortening, mitochondrial damage, senescent cells and accumulated protein damage.
Ageing affects every system gradually. Lifestyle modifies trajectory. Frailty is a decline in reserve.
Key idea: ageing is the accumulation of damage and reduced repair.
With age, maximal heart rate declines (a rough guide of 220 minus age), arteries stiffen so systolic pressure rises, lung elasticity and vital capacity decrease, kidney function (GFR) falls about 1 mL/min per year after 30, muscle mass declines by 3 to 8 percent per decade after 30, and bone density falls. The immune system weakens (immunosenescence), skin thins, lens becomes less flexible (presbyopia), hearing of high frequencies drops, and sleep changes. Cognitive speed slows although vocabulary can continue to grow.
Theories include accumulated cell damage (free radicals), telomere shortening, mitochondrial dysfunction, senescent cells, and epigenetic changes; caloric restriction extends lifespan in many animals. Exercise, diet, social engagement and avoiding smoking and excessive alcohol support healthy ageing. Healthspan, not only lifespan, is the goal.
Key idea: ageing is gradual loss of reserve capacity, making recovery from stress harder.
Frequently asked questions
What is Ageing Physiology?
Declining stem cell function, accumulating damage and reduced repair gradually lower organ capacity.
Which area of biology covers Ageing Physiology, and how advanced is it?
Ageing Physiology is one of the 51 topics in Human Physiology. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Diabetes Mellitus, Exercise Adaptations, Energy Balance and Metabolism.
Can you give an example of Ageing Physiology?
Exercise slows many age-related declines.
What should I learn before Ageing Physiology?
Work through the Beginner topics in Human Physiology first, such as Homeostasis, Tissues and Organs, Skeletal System, then return to Ageing Physiology. Advanced topics assume the Intermediate vocabulary.
What topics are related to Ageing Physiology?
The closest topics to Ageing Physiology are Diabetes Mellitus, Exercise Adaptations, Energy Balance and Metabolism, Breathing Mechanism. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Ageing Physiology?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Ageing Physiology. To practise the whole of Human Physiology, use the Human Physiology quiz.
How is Ageing Physiology different from Diabetes Mellitus?
Ageing Physiology: Declining stem cell function, accumulating damage and reduced repair gradually lower organ capacity. Diabetes Mellitus: Type 1 results from loss of insulin-making cells and type 2 from insulin resistance, both leaving high blood glucose. Read both side by side and note what each one explains.
How should I study Ageing Physiology step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Diabetes Mellitus and explain the difference aloud. Finally, take the Human Physiology quiz and come back to this page for any question you miss.