Stem Cell Biology and Aging Concepts

A process where stem cells lose their ability to function properly, often due to chronic inflammation.

Long-term inflammation that is damaging to cells and tissues.

Stem cells dividing to form differentiated cells.

An irreversible process that cells undergo and can only be slowed down, not stopped.

The process of reducing the activity of the immune system. In some instances, helping to restore cells to a resting phase.

A process where stem cells stop dividing and enter a non-dividing state, affecting wound healing.

A control mechanism that ensures accurate cell division; it's lost when cells enter senescence.

A molecule used to track DNA replication, visualizing cell proliferation.

A protein found in cells actively dividing (growing), marking the cell cycle.

Non-dividing cells; markers like p16 and p21 detect this state.

The process of cells multiplying.

Temporary senescence, helpful for a limited time.

Chronic, prolonged senescence, often causing harm (eg, inflammation).

A condition where cells become less responsive to insulin, preventing glucose from entering them effectively. This can result in high blood sugar levels.

A protein that helps glucose move from the blood into cells. It is activated by insulin, allowing glucose uptake.

In insulin resistance, GLUT4 transporters don't properly relocate to the cell membrane, blocking glucose uptake.

Insulin acts like a messenger, telling cells to take up glucose from the bloodstream.

Beta cells in the pancreas overproduce insulin to compensate for insulin resistance, eventually leading to exhaustion and reduced insulin production.

A healthy circadian rhythm improves muscle insulin sensitivity by regulating protein levels involved in glucose uptake.

A dietary approach where eating is restricted to a specific window of time. This can improve glucose tolerance and prevent weight gain.

Insufficient sleep disrupts energy balance, leading to increased appetite and reduced energy expenditure, ultimately impacting weight and glucose control.

Nuclei found within muscle fibers (myofibers). They contain the genetic material needed for muscle protein synthesis.

A long, cylindrical structure that makes up muscle fibers. They contain repeating units called sarcomeres, which are responsible for muscle contraction.

The basic unit of muscle contraction. It contains the proteins actin and myosin, which slide past each other during muscle contraction.

Proteins that form the sliding filaments within sarcomeres. Actin is thin, while myosin is thick.

The process by which muscles shorten and generate force. This is achieved by the sliding of actin and myosin filaments past each other.

Macromolecules like DNA and RNA cannot be stored in cells because they are constantly being used and recycled. They carry genetic instructions for building and maintaining the cell.

The more sarcomeres a myofibril has, the more potential for contraction and thus, greater strength. This is because each sarcomere contributes to overall force generation.

Myonuclei are initially located near the center of the myofiber, but as the myofiber matures, they move outwards, closer to the membrane.

Carbohydrates are stored as glycogen primarily in skeletal muscles, especially for use by type II muscle fibers (those involved in resistance exercise). They are also temporarily stored in the liver.

Lipids are stored as triglycerides. Endurance athletes have more type I muscle fibers (oxidative), which use lipids as energy.

Marathon runners adapt to use lipids as fuel during prolonged exercise, while resistance athletes adapt to utilize carbohydrates for quick energy bursts.

When protein synthesis exceeds protein degradation, muscle hypertrophy (growth) occurs.

When protein degradation exceeds protein synthesis, muscle atrophy (loss) occurs.

The process of building proteins, often associated with muscle growth.

The breakdown of proteins, often associated with muscle loss.

A balance between protein synthesis and degradation, ensuring proper functioning cells and tissues.

Type I muscle fibers are oxidative, using oxygen and lipids as energy and type II muscle fibers are glycolytic, using glucose for quick energy.

Muscle fibers receive signals from sensory neurons (muscle spindles) to coordinate contraction.

The rigidity and reduced flexibility of arteries, making it harder for blood to flow through.

A diet that drastically reduces calorie intake without sacrificing essential nutrients.

The widening of blood vessels by the endothelium, the inner lining of blood vessels, to improve blood flow.

The amount of nitric oxide (NO) available in the body to perform its functions, like vasodilation.

A process where the circulatory systems of two animals with different ages are joined together.

Drugs that selectively remove senescent cells from the body.

A drug that can extend lifespan in animals and has shown potential to delay aging.

A signaling molecule that promotes inflammation in the body.

A protein that forms the framework of the aorta, the main artery in the body.

Muscle cells found in the walls of blood vessels that control their diameter.

A protein that plays a crucial role in longevity and protects against aging-related decline.

A molecule that can boost SIRT1 activity and has shown potential for reversing age-related decline.

A molecule found in red wine and grapes that has shown potential for extending lifespan.

A small molecule that can activate SIRT1 and has shown promise for treating age-related diseases.