hypertrophy

Examples of hypertrophy in the following topics:

• Muscular Atrophy and Hypertrophy

  • Muscle hypertrophy is an increase in the size of a muscle through an increase in the size of its component cells.
  • Several biological factors such as age and nutrition can affect muscle hypertrophy.
  • During puberty in males, hypertrophy occurs at an increased rate.
  • Natural hypertrophy normally stops at full growth in the late teens.
  • An adequate supply of amino acids is essential to produce muscle hypertrophy.

• Impacts of Exercise on Muscles

  • Sustained, repeated overload of a muscle group leads to hypertrophy and strengthening of those muscles.
  • Muscle hypertrophy, or the increase in muscle mass due to exercise , particularly weight training, is a noticeable long-term effect of exercise.
  • Exercise of specific muscles can often result in hypertrophy in the opposite muscles as well, a phenomenon known as cross education.

• Congestive Heart Failure

  • Hypertrophy (an increase in physical size) of the myocardium also results as a compensatory mechanism when the terminally differentiated heart muscle fibers increase in size in an attempt to improve contractility.
  • Ultimately, hypertrophy may contribute to the increased stiffness and decreased ability to relax during diastole.
  • Ventricular hypertrophy will also contribute to the enlargement and spherical shape of the failing heart and may reduce stroke volume due to mechanical and contractile inefficiency.
  • A healthy heart (left) and one suffering from right ventricular hypertrophy (right).

• Pylorospasm and Pyloric Stenosis

  • There is narrowing (stenosis) of the opening from the stomach to the first part of the small intestine known as the duodenum, due to enlargement (hypertrophy) of the muscle surrounding this opening (the pylorus, meaning "gate"), which spasms when the stomach empties.
  • This hypertrophy is felt classically as an olive-shaped mass in the middle upper part or right upper quadrant of the infant's abdomen.
  • In pyloric stenosis, it is uncertain whether there is a real congenital narrowing or whether there is a functional hypertrophy of the pyloric sphincter muscle.

• Effects of Exercise on the Heart

  • A sedentary and inactive lifestyle is associated with greater risk for hypertension, cardiac hypertrophy, artherosclerosis, and myocardial infarctions, due to the metabolic changes that accompany a sedentary lifestyle.
  • For example, some athletes may be at risk for cardiac hypertrophy from too much exercise over long periods of time, and sudden cardiac death from exercising to the point that the heart's metabolic demands become too high, causing an arrythmia.

• Postnatal Bone Growth

  • 3) Zone of cell hypertrophy: The stop dividing and begin to hypertrophy (enlarge).

• Anabolic Steroids and Muscles

  • Anabolic steroids are testosterone and dihydrotestosterone hormone mimics that stimulate anabolism, specifically protein synthesis and muscle hypertrophy.

• Adjustments During Exercise

  • While many factors that can lead to sudden cardiac death in athletes are genetic (such as inherited problems with heart rhythm or coronary artery blood supply), many of these deaths are caused by cardiac hypertrophy, in which the heart becomes too thick from damage and scarring from too-intense exercise over long periods of time.
  • Initially, hypertrophy improves blood flow due to increases in the strength of the heart, but it eventually leads to heart failure as the tissues become too thick to pump normally.
  • Athletes with genetic susceptibilities are more likely to experience sudden cardiac death as a response to their hypertrophied heart, which can contribute to development of a severe arrhythmia (such as ventricular fibrillation).

• Creatine Supplementation

  • Creatine supplementation can also cause an increase in muscle mass (muscle hypertrophy).

• Myocardial Thickness and Function

  • Cardiac hypertrophy is a common result of hypertension (high blood pressure) in which the cells of the myocardium enlarge as an adaptive response to pumping against the higher pressure.