Cell Hypertrophy
Many stimuli, such as hormones (biological factors) or increased mechanical tension (environment factors), can directly affect cells and cause hypertrophy. The body releases growth hormone through a series of events and signals. The specific cells are then affected by the growth hormone to increase protein synthesis. Muscle hypertrophy can only occur if the rate of protein synthesis is faster than natural protein loss. In order to provide more energy for hypertrophic cells, many organelles, including the mitochondria, will also increase in size. The diagram below shows other processes that can be triggered. This is only for hypertrophy of muscle cells.
Hypertrophy causes cell changes
Physiological Hypertrophy
Physiological hypertrophy refers to hypertrophy that is beneficial or good for the body. As mentioned above, physiological hypertrophy can be found in many areas of the body including the muscles and heart. This can also be caused by genetic, environmental, and biological factors.
Exemples of Physiological Hypertrophy
These are some examples of physiological hypertrophy:
* Muscle mass increases which leads to more strength
* Healthy exercise without pathological conditions may result in an increase in the size of heart cells, which will allow for increased pumping efficiency and pumping power.
* Exercise releases growth hormones which can increase the size of brain cells or neurons.
* To allow growth and protection of the foetus, uterine cells will increase in size as a result of pregnancy.
* An increase in the size of kidney cells in one kidney is necessary to compensate for increased workload following the donation or loss of a second kidney.
Hypertrophic pregnant Uterus vs. Normal Uterus
Definition and types of Muscle Hypertrophy
Muscle hypertrophy is caused by the physiological process. When a person lifts weights, muscle cells alter their structure and the composition of organelles to increase the size or strength of the muscle. Each muscle contains individual muscle fibers, called myofibrils. These are responsible for its strength. The sarcoplasm is the rest of the area around the myofibrils. When strength training, people will use myofibrillar Hypertrophy. Bodybuilders will use sarcoplasmic Hypertrophy. Bodybuilding is achieved by using lower weights and more repetitions. Strength training is accomplished with higher weights and fewer repetitions. Both types of muscular hypertrophy are caused by eating lots of protein and eating more calories than what you’re consuming. Myostatin-related muscular hypertrophy, a genetic condition, is the third type. Depending on the stimulus, muscular hypertrophy may be defined as an increase in muscle volume without an increase of strength.
Sarcoplasmic vs. myofibrillar muscular hypertrophy
Myofibrillar Hypertrophy
Myofibrillar Hypertrophy can be defined as the physiologic hypertrophy, which occurs through muscle and strength training. The body attempts to repair or reconfigure damaged cells by tearing them or rupturing them. This leads to an increase of cell density, volume and overall size. This type of hypertrophy sees the number of myofibrils that are responsible for muscle strength increasing. Myofibrillar Hypertrophy is a way to increase muscle strength.
Myostatin-related muscular hypertrophy (or myostatin-related muscle wasting) is a rare genetic condition that causes individuals to have smaller bodies and more muscular cells. They can have twice as much muscle mass and greater strength. It is due to a genetic mutation.
Sarcoplasmic Hypertrophy
Sarcoplasmic hypertrophy is a swelling of cells due to the growth of the sarcoplasmic liquid within them. This causes an increase of cell volume but not an increase in strength.
Pathological Hypertrophy
While physiologic hypertrophy can be beneficial for the body and is good for your health, pathological hypertrophy can cause damage to your body. Pathological hypertrophy is an increase of cell size caused by unfavorable stimuli, such as inflammation. This causes the cells to become larger and the cells to function less efficiently. This can have many adverse effects on the body, including a cascading of inflammatory pathways, inability or inability to eliminate toxins and pathogens, inability or inability to absorb nutrients and energy, and even the initiation and exacerbation chronic medical conditions.
Pathological Hypertrophy: Signs and Symptoms
Pathological hypertrophy can manifest in many ways. These include the retention of inflammatory fluid in cells that causes swelling and difficulty breathing, an increase in the size of the pleural tissue, increased fatigue, and decreased efficiency due to hypertrophy of cardiac cells. A stroke or acute myocardial injury can result from serious symptoms such as difficulty breathing and poor circulation.
Examples of Pathological Hypertrophy
These are some examples of pathological hypertrophy:
* A person’s excess weight can cause an increase in the size of fat cells, which in turn leads to higher cholesterol and triglyceride stores.
* A rise in the size of heart cells due to untreated medical conditions, such as high bloodpressure, can lead to a decrease of efficiency and myocardial damage.
Hypertrophic heart versus normal heart in cardiomyopathy
What causes hypertrophy?
Hormonal causes and excessive inflammation are also biological factors that can cause hypertrophy. It can be caused by increased nutrient storage capacity and capacity within cells. Muscle or strength training is one example of an environmental factor that can cause cellular hypertrophy in muscles. Pathological hypertrophy can be caused by untreated medical conditions, inflammation and an increase in age.
Hypertrophy Treatment
Different pathological hypertrophies can be treated with different treatments. A person with increased fat cell size and subsequent increase in cholesterol and triglyceride stores would be encouraged to exercise and to eat better. Pathological myocardial Hypertrophy is a condition that occurs as a result of untreated medical conditions. They would be prescribed high blood pressure medication to lower blood pressure, dilate blood vessels and reduce resistance to prevent excessive hypertrophy of the heart cells. To treat hypertrophy caused by infection or cancer, a person’s cells would require specific chemotherapy and antibiotics.
Lesson Summary
Hypertrophy is a physiological or pathologic rise in cell size caused by biological, environmental or genetic factors. There are many types of physiologic or pathologic hypertrophy in the human body. Muscular hypertrophy, which is a type of beneficial physiologic hypertrophy, is an example. There are three types. Different pathologies require different treatment depending on what caused them.
