Anatomy-Lexicon

hypertrophy

definition

The term hypertrophy is made up of the ancient Greek words "hyper"(Excessive) and"trophein“(Feed) together. In medicine, hypertrophy describes the enlargement of an organ because the individual cells of the organ increase in size. With hypertrophy, the individual cells of the organ are enlarged, but the number of cells remains the same.

Hypertrophy can occur as a normal, desired change or as a pathological reaction of an organ. Hypertrophy develops through hormonal stimulation of the hypertrophic organ or as Reaction to increased demandsto which an organ has to react: For example, the heart of athletes enlarges due to hypertrophy when it is stressed by regular exercise, which increases the athlete's physical performance.
A But hypertrophy doesn't have to be positive. At a Valvular heart disease the heart reacts to the increased demand with pathological hypertrophy. Hypertrophy is often confused with the term hyperplasia. However, this leads to an enlargement of an organ because the cells divide more intensely. The size of the individual cells remains roughly unchanged in hyperplasia.

Muscle cell hypertrophy

A muscle consists of long muscle fibers, each muscle fiber is the result of the fusion of many mononuclear precursor muscle cells. A muscle cell thus has several nuclei and corresponds to a muscle fiber that can be a few centimeters long. The nuclei of a muscle cell can no longer divide, which is why it is not possible for muscle tissue to multiply through cell division. So muscle fibers can only grow through hypertrophy. A muscle grows as each individual muscle cell increases in size.
When muscle cells grow, the required nuclei are made available by muscle precursor cells, which are located at the edge of a muscle fiber, by fusing the muscle precursor cells with the muscle fiber. This amalgamation occurs both in the growth of children into adults and in the growth of muscles through exercise. Regular exercise the musculature represents one Growth stimulus for the muscle cells. Both endurance and strength sports stimulate the muscles to hypertrophy, but targeted strength training is a stronger growth stimulus than endurance sports and therefore leads to greater hypertrophy. Growth factors are released and the muscle metabolism is “ramped up” so that the muscle cells hypertrophy.

Muscle fibers are made up of one large proportion of proteins (Protein), so protein is required for muscle growth. A protein-rich diet can the Support hypertrophy of the muscles, but not trigger.

Also hormonal factors have an influence on the hypertrophy of the muscles. The male sex hormone testosterone additionally accelerates muscle growth. Since a man's testosterone level is many times higher than that of a woman, men find it easier to build muscle mass through exercise. Testosterone is not the only substance that promotes male muscle growth. Recent research shows that strength training releases additional chemical messenger substances in a man, which promote hypertrophy of the muscles. These messenger substances are missing in women. Despite these differences, the basic structure of the muscles in men and women is the same. Prohibited doping substances Like anabolic steroids, the muscles also stimulate growth and thus facilitate hypertrophy of the muscle cells.

Hypertrophy from the heart

The heart ensures that blood is pumped around the body and is made up of heart muscle cells. A Hypertrophy of the heart means that the individual heart muscle cells grow, but their number remains unchanged.
causes for this there can be various diseases of the heart, the most important of which are Valvular heart disease, high blood pressure, Heart failure and the Hypertrophic cardiomyopathy (HCM).Heart valve defects can occur in any heart valve; the aortic and mitral valves in the left part of the heart are most frequently affected, as this belongs to the body's circulation and is more stressed than the right part of the heart due to the significantly higher blood pressure than in the pulmonary circulation.

At a Stenosis the affected flap can itself not opening properlywhich puts even greater pressure on the heart. The heart responds with one Inward growth (concentric hypertrophy).

At a insufficiency the affected flap can itself do not close properly, whereby the heart is stressed by excess blood volume, it reacts with a Outward growth (eccentric hypertrophy).

Aortic regurgitation
Mitral valve regurgitation

At high blood pressure must be the heart against greater resistance work than usual. In the Heart failure or Heart failure the heart is no longer able to pump enough blood around the body to supply all organs. The body tries, therefore, by means of hypertrophy To improve the heart's pumping capacity. This method works well for some time, but if the critical weight of 500g is exceeded, the heart itself can no longer be adequately supplied with blood and the heart's performance decreases again.

The Hypertrophic cardiomyopathy is the most common hereditary heart disease, but it can also occur without an apparent cause. About 200 out of 100,000 people are affected. Of the Heart muscle thickened especially in the left ventricle in the area of the heart septum, whereby the ejection of blood into the body's circulation can be disturbed, the disease is then called Hypertrophic obstructive cardiomyopathy (HOCM) designated. For a long time the patients have no symptoms; the non-obstructive form in particular is often only discovered by chance and is one of the most common causes of sudden cardiac death in young athletes. Possible symptoms are Shortness of breath, a feeling of Chest tightness and Cardiac arrhythmias. In milder forms, this disease can be treated with medication (beta blockers or calcium channel blockers); in more severe cases, only an intervention in the heart catheter laboratory, in which the thickened heart septum is removed by capping the blood supply, will help.

Turbinate hypertrophy

The turbinates (Conchae nasales) are located inside the nose, where the nose is no longer made of cartilage but of bone. There are three turbinates on each side: an upper one, a middle one and a lower one.
The turbinates are small, bone ridges covered with mucous membrane. The turbinates enlarge the surface of the nasal mucous membrane and thus improve the defense against inhaled foreign bodies and pathogens, because in the optimal case these simply stick to the nasal mucous membrane.
The turbinate hypertrophy means that the turbinates are enlarged. An enlargement of the turbinates can, for example from hay fever and other allergic inflammation or through the excessive use of nasal decongestant spray to be triggered.
On the one hand, this hypertrophy causes the breathing through the nose with special needs, on the other hand, the drainage of the paranasal sinuses is difficult. Affected patients find it difficult to breathe, especially during physical exertion; some also snore at night. The obstructed outflow of the paranasal sinuses promotes infections of the upper respiratory tract and chronic sinus infections. The most effective therapy for severe discomfort caused by enlarging the turbinates is surgical reduction.

Breast hypertrophy (mamma)

Mamma hypertrophy describes a female breast that is too large, some Definitions call a Weight of over 1,000 grams per side as a threshold for diagnosing breast hypertrophy. The hypertrophy of the mamma can on one side or on both sides occur. The high weight puts a strain on the musculoskeletal system and leads to poor posture in the affected patients, which is why back and shoulder pain are not uncommon in breast hypertrophy. In most cases, this is the trigger for breast hypertrophy puberty, but also the hormonal changes during pregnancy can trigger breast hypertrophy.
At Men becomes a benign enlargement of the mammary gland as Gynecomastia It can be triggered, for example, by a lack of male sex hormones or by certain drugs. An enlargement of the male breast due to obesity is a so-called Pseudogynecomastia, since the gland is not enlarged here, but more fat is stored in the breast.

The therapy of choice for breast hypertrophy and real gynecomastia is one surgical breast reduction.

Facet joint hypertrophy

Each vertebral body has two upward and two downward-facing articular surfaces, which are called Facet joints (Facies articularis superior or. inferior) are designated. The facet joints connect the individual vertebral bodies with each other and thus enable the mobility of the spine. The shape and alignment of the facet joints are the reason for the different degrees of movement in the spine. The cervical spine is very flexible, whereas the thoracic spine is less flexible. A Facet joint hypertrophy joins age and wear and tear Changes on. It comes to New bone formation, as Spondylophytes are designated. With these bone additions, the body tries to reduce the pressure on the facet joint by increasing the area. Unfortunately, this hypertrophy of the facet joints causes the Limited mobility of the spine and the Spinal canal narrowedwhat a Spinal stenosis can contribute.

Ligamenta flava

The ligaments are flava very thick and strong bandsthat connect the individual vertebral bodies in the area of the vertebral arches (the part of the vertebral body that surrounds the spinal canal). For the most part, they consist of elastic fibers that give them their yellow color (lat. Flavus - yellow) and form the rear end of the spinal canal.
The ligamenta flava support the back muscles in stabilizing the spine when standing upright and prevent the spine from tilting forward. A Hypertrophy of the ligamenta flava occurs in the frame degenerative diseases, one Back muscle weakness or in response to a herniated disc, which is rarely the case. The result can be spinal stenosis. The spinal canal is narrowed, causing stress-dependent pain and sensitivity disorders in the arms or legs.