Incredible Facts
Some organs in the human body exist not because they serve a purpose, but because they were useful to our ancestors.
They remained as rudiments - physiological remnants of our evolutionary past.
Take a closer look and you will see that they make sense in terms of evolution by natural selection.
The structure of the human body
long palmar muscle
The long palmar muscle is a vestigial muscle of the forearm. This is a group of muscles that runs from the base of the palm up the arm.
It can be found among many mammals, but it is most developed in those who often use their forearms for movement, such as monkeys and lemurs. 10-15 percent of people no longer have this muscle, sometimes it is present in only one arm., although this does not affect the compression force.
This muscle is often removed by surgeons when needed. Plastic surgery in other parts of the body.
Anterior, superior and posterior ear muscle
Some people can wiggle their ears. The muscles that enable them to do this are vestigial: the anterior auricular, superior auricular, and posterior auricular muscle.
These same muscles allow other mammals to move their ears to hear sounds better and to identify their source.
In fact, people try to move their ears in the direction of the sound, but these movements are very small and can be picked up with electrodes.
Goosebumps
When we are cold, tiny the muscles attached to the hairs on our body contract and lift the hairs, which causes goosebumps on the skin.
In furry mammals, this creates better insulation and a more intimidating appearance in case of danger. Emotional music can also cause goosebumps, as it is triggered by the fight-or-flight response associated with the production of adrenaline.
Coccyx
The coccyx is also a relic of our ancestors' tail.
Each of us had a tail at some point in our development - around the fourth week of fetal development. Human embryos are very similar to those of other vertebrates, including the tail. However, in humans and other primates, tail cells are programmed to die.
It is a short spindle-shaped abdomen and a very long tendon, stretching almost from the elbow to the wrist. Oddly enough, 14% of people simply do not have it.
Anatomical experts argue that the absence of this tendon does not affect grip strength in any way. However, in case of any specific injury, when the need for transplantation arises, it is good source- a kind of spare part in the human body.
To check if you have it, gather all five fingers into a pinch and bend your wrist - the tendon is clearly visible in the wrist area, provided that it is present. In other mammals, this same tendon is responsible for extending the claws. Apparently, this is why some people do not have it - there is no need to release claws in our species.
Tendons can look very different from person to person. Just as individual is the number of tendons and muscles.
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Close your fingers as shown in the picture. See that tendon? That's what it means... Over the past 200 thousand years, man has stepped forward a lot if we are talking about evolution.
Close your fingers as shown in the picture: Even though we are very similar to our ancestors, modern man differs in many physical and anatomical features. This is proved by rudimentary organs that are scattered throughout the human body.
Scientists call vestigial organs those parts of the body that have lost their functions over time, but are still preserved in the human body. Mother Nature considers these organs unnecessary for life, their activity fades, but by themselves they still remain unchanged.
Why some parts of the body and their functions remain in the body, while others completely disappear is a real mystery of nature. Most of them do us no harm, and those that can do it (we are talking about wisdom teeth and the appendix) are easily removed.
Well-known examples of vestigial organs are the appendix, goosebumps, wisdom teeth, tonsils, male nipples, and the outer ear. Once upon a time, these body parts performed important functions in the human body, but today there is no need for them.
How to trace evolution on the example of your organism? Everything is very simple! Place your hand on a flat surface, palm up. Close your little finger together and thumb, and then lift them up slightly.
If you see a ligament in your wrist, then you have a vestigial muscle in your forearm. It is called like this: long palmar muscle (lat. palmris longus).If a muscle is missing from one or both arms, then you are in the 10-15% of the population.
Don't worry if you don't find this muscle. IN modern life she is useless. Studies have shown that the long palmar muscle has no effect on the strength of a person's hand.
It turns out that these muscle fibers are responsible in animals for the release of claws! It is also present in all primates and enhances grip when jumping from tree to tree. It is clear that a person is now to nothing.
Ecology of life. Cognitively: 200 muscles are included in the work with just one step. The heart, the most enduring muscle in the body, works constantly. Muscles grow and train...
200 muscles are included in the work with just one step. The heart, the most enduring muscle in the body, works constantly. Muscles grow and train, tons of sports literature have been written about them. We will tell you the most interesting.
1. How many muscles in total?
In total, there are from 640 to 850 muscles in the human body. During a simple walk, the body uses up to 200 muscles. Muscle tissue is 15% denser and heavier than fat, so a trained person can outperform a full but unathletic person of the same height in weight. Muscles account for an average of 40% of body weight.
2. The most-most muscles
The most enduring human muscle is the heart, the shortest is the stirrup (it strains the eardrum in the ear). Its length is 1.27 mm. longest muscle human body- tailor. The most fast muscle- blinking. There are different opinions about which muscle of the body is the strongest. It is often said that the most powerful muscle is the tongue, but the tongue is made up of several muscles, so this view is false. Chewing muscles are very strong (their pressure can reach 100 kilograms), as well as calves and gluteal muscles.
3. Such different muscles
Human muscles are not the same. Therefore, they need to be trained in different ways, and the recovery time and different groups muscles is different. The triceps recover the fastest, the back muscles the slowest. This must be taken into account during training, the muscles need rest no less than the load, since the growth of muscle fibers occurs due to the effect of supercompensation. Full muscle recovery occurs only 48 hours after intense exercise.
4. Muscle Endurance
Endurance - the ability of a muscle to maintain performance over time. The most enduring muscle of the human body, as we have said, is the heart. According to doctors, the "margin of safety" of the average heart is at least 100 years. Muscles begin to tire when they run out of glycogen, and fatigue is also explained big amount in muscle calcium. Previously, it was believed that the main culprit of fatigue is lactic acid. Columbia University conducted a study in which mice swam daily for three weeks and cyclists exercised for three days. It turned out that after exercise in the chemical structure of the ryanodine receptor, which is responsible for muscle contraction, there were major changes- there was a gap in the cell membrane through which calcium seeped into muscle cells.
5. Muscles and emotions
It is known that the movement of facial muscles is directly related to human emotions. At the beginning of the last century, the Russian scientist Ivan Sikorsky compiled a classification of facial expressions: the muscles around the eyes are responsible for the expression of mental phenomena, the muscles around the mouth are for the expression of acts of will, and all the muscles of the face express feelings. In 2011, scientists managed to discover that human facial expressions occur long before birth. Even during the prenatal period, the child is already able to move facial muscles, smile, raise eyebrows in surprise or frown. The facial muscles make up 25% of the total number of muscles, while smiling, 17 muscle groups are involved, during anger or crying - 43. One of better ways maintaining smooth skin on the face - kissing. With them, from 29 to 34 muscle groups work.
6. Muscles and genes
Amazingly, muscle training has an impact not only on the person himself, but also on his genes. They undergo modifications that further help the muscle fibers to be ready for new loads. In order to prove or disprove this, scientists from the University of Aarhus recruited a focus group of 20 volunteers and spent a 20-minute session with them. aerobic exercise on an exercise bike. After the study, a quadriceps biopsy was taken from the subjects to see how the genes had changed in their cells. It turned out that exercise stress activates genes related to muscles. This is because cells store DNA with the help of methyl groups. If they are removed, the gene information is converted into enzymes and proteins, which are necessary for burning calories, gaining muscle mass and oxygen consumption. After the experiment, the number of methyl groups decreased in all participants in the study - that is, the muscles adapted to an increase in metabolism.
7. Muscles and telepathy
A simple person is not able to establish control over all the muscles of the body, therefore, unconscious muscle contractions can serve as an indicator of hidden thoughts or intended actions for knowledgeable people. Psychologists high level and "telepaths" can use knowledge about these processes. Wolf Messing, one of the most famous telepaths, explained his phenomenal abilities not by magic, but by a thorough knowledge of the work of human muscles. He said: “This is not mind reading, but, so to speak, “muscle reading” ... When a person thinks hard about something, brain cells transmit impulses to all the muscles of the body.”
8. Long palmar muscle
Only one in six people on earth have long palmar muscles on both hands. Some have them on only one of their hands. These muscle fibers are responsible for the release of claws in animals. A person, of course, does not need such a function. The long palmar muscles are thus a vestige used by surgeons, if necessary, as a material for muscle transplantation.
9. Muscles and chocolate
Oddly enough, one of the most useful products for the heart and for the muscles in general is bitter chocolate. Research conducted at Wayne University in Detroit revealed the effect of the substance epicatechin contained in dark chocolate on the growth of mitochondria in muscle cells. Scientists at the University of L'Aquila also conducted a study in which they gave subjects 100 grams of chocolate for 15 days and measured their blood pressure. During the experiment, blood pressure normalized in people, blood circulation improved. Accordingly, moderate consumption of dark chocolate can be considered as a prevention of heart disease and atherosclerosis.
10. Muscle Loss
Muscles don't last forever. After 40 years, they begin to be actively burned, a person begins to lose from 2 to 3 percent per year. muscle tissue, after 60 years - up to 5%. Therefore, training in adulthood is no less important than in youth. published
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As tendon autografts, tendons are used, the taking of which does not cause significant functional and cosmetic disorders.
The tendon of the length of the palmar muscle has a significant length (from 15 to 20 cm or more, including the intramuscular part), a sufficient area cross section and strength. Its loss does not cause functional disturbances, and taking it does not cause technical difficulties.
Disadvantages of this source tendon grafts relate limited quantity plastic material, the absence of a tendon in 15% of people and sometimes its insufficient length. In this regard, the tendon of the long palmar muscle is most often used for plastic surgery of the flexor tendon on the short fingers of the hand (I and V), when only one finger is damaged. At multiple injuries fingers, it is preferable to use other sources of plastic material.
Taking technique. You can check for the presence of the tendon of the long palmar muscle if you strain the straightened fingers of the hand with some flexion in the wrist joint (Fig. 14.5.1). From a small transverse approach, the tendon is exposed at the point of transition to the palmar aponeurosis. When doing this, be careful not to damage the adjacent median nerve.
Rice. 14.5.1. Test for assessing the presence of the tendon of the long palmar muscle.
The end of the tendon is stitched and cut off, after which, when pulling on the ligatures with simultaneous palpation, it is easy to determine its course under the skin. This makes it possible to completely isolate the tendon from two additional transverse approaches to its intramuscular section (Fig. 14.5.2, a), after which it is cut off from the muscle belly. This procedure can also be performed from one access using a special tool - a tendon rasp (Fig. 14.5.2, b).
Rice. 14.5.2. Schematic representation of the approaches used to take the tendon of the long palmar muscle (explanation in the text).
Tendons long extensors II-V toes. This source is characterized by a significant number of donor tendons (4 on each foot), their significant length (up to 25–30 cm), as well as minor loss of function and a cosmetic defect after taking.
At the same time, sometimes the tendons are not thick enough (more often on fingers IV-V), and their isolation for the entire length is technically difficult. This source of tendons is widely used in hand surgery, as well as in reconstructive operations on other segments.
Taking technique. On a bloodless segment, from short (5 mm each) transverse incisions at the level of the heads of the metatarsal bones (Fig. 14.5.3, b), the ends of the tendons of the long extensor of the II-V fingers are isolated, stitched and cut off. In this case, the tendons of the short extensor of the same fingers must be preserved.
From the next transverse approach at the level of the transverse joint of the tarsus (Shopar joint), all 4 tendons located next to each other can already be isolated. From the third longitudinal access up to 8 cm long, located immediately above the proximal edge of the ligament supporting the extensor tendons, the tendons of the long extensor muscles of the II-V fingers are exposed, which usually cannot be divided, since they represent one common trunk.
After that, the tendon sheath is carefully opened and the Rozov conductor is inserted into it in the distal direction, trying to go to the nearest incision along the surface of the extreme tendon. With the help of a conductor, each tendon is brought into the proximal wound and, thus, the common tendon trunk is separated. Then the tendons are cut off from the muscle, and after removing the tourniquet and stopping the bleeding, the wound is tightly sutured in layers (including deep fascia).
When using a tendon rasp, access to the shins is not necessary, and the procedure for taking grafts is simplified (Fig. 14.5.3, a).
Rice. 14.5.3. Accesses and stages of taking the tendons of the long extensor of the toes (explanation in the text).
For special indications, the extensor toe longus tendons can be included in the dorsal foot flap and used as vascular grafts.
The tendons of the superficial flexors of the fingers are used in plastic surgery of the tendons of the deep flexors of the fingers. Their advantages include their considerable thickness, length and quantity, as well as the simplicity of the technique of taking. According to their characteristics, they are best suited for deep tendon replacement. However, their use also has significant disadvantages.
First of all, in short-toed subjects, these tendons can be relatively short. This causes them to be taken along with the intramuscular part, after which the muscle can no longer be used, and the flexion force of the finger is markedly reduced. In addition, taking the tendons of the superficial flexors requires significant accesses, which is also disadvantageous from a cosmetic point of view.
It is important to note that this donor zone is located along the bone-fibrous canals of the fingers and therefore is the most unfavorable (in comparison with any other zones) due to the negative influence of cicatricial adhesions that inevitably form around the deep flexor tendons of the donor finger. Such a finger in the postoperative period itself requires a full rehabilitation, which may not always result in a complete restoration of function.
That is why it is advisable to use the superficial flexor tendons of only the injured finger and only when the level of injury is in the “critical” zone.
With injury at a more proximal level, the tendon graft may become too short for its effective application. Transposition of the tendon of the superficial flexor from the adjacent, longer and intact (!) finger is a gross mistake.
Taking technique. Together with the proximal end of the damaged tendon of the deep flexor of the finger, the superficial tendon is isolated from the appropriate access to the hand and brought into the S-shaped wound on the forearm. Then the tendon of the superficial flexor of the finger is isolated to the level of the muscle and cut off, after flashing its end remaining in the muscle. The latter is sutured to the central end of the deep flexor tendon after its restoration.
The tendon of the plantar muscle has a significant length and thickness, which allows it to be used in hand tendon surgery. Its disadvantage is the limited amount of plastic material, which allows using this source only for tendoplasty on one finger. In addition, the tendon is missing in 7% of people and cannot be identified before surgery.
Taking technique. From a 5-cm vertical incision anterior to the medial edge of the calcaneal tendon, the tendon of the plantar muscle is isolated and taken with a tendon rasp (Fig. 14.5.4). In this case, the instrument should pass parallel to the axis of the lower leg when unbent in knee joint limbs.
Rice. 14.5.4. Scheme of taking a graft from the tendon of the plantar muscle (explanation in the text).
The fascia lata of the thigh is a practically unlimited source of plastic material and should be rolled into a tube when replacing large tendons. Due to the fact that its surface does not have such high slip rates, flaps from the wide fascia of the thigh are not used to replace defects in the flexor tendons of the fingers.
At the same time, their transplantation can give good result when replacing other tendons, including in the form of blood-supplied grafts, including skin-fascial flaps from the outer surface
hips.
Autoplasty of tendons
The use of autotendons for tendoplasty is the most common in clinical practice. Depending on the specific conditions, five of its main options are used.One-stage graft tendoplasty is the most common operation in which a tendon insert is sutured into a tendon defect.
In the vast majority of cases, this type of operation is performed with chronic injuries of the flexor tendons of the fingers.
Two-stage tendoplasty is used exclusively in finger flexor tendon surgery and lies in the fact that during the 1st stage of treatment, more favorable conditions are created for subsequent tendon graft transplantation.
Tendoplasty, combined with transplantation of complex skin flaps. With a combination of tendon defects with skin defects, these two problems can be solved simultaneously, since only if the tissues surrounding the tendon are in a normal state, their function can be restored.
Most often this situation occurs with injuries of the forearm in the lower third. After transplanting a complex skin flap into the defect, tendon grafts can be passed through the latter.
These two tasks can also be solved sequentially in the course of a two-stage treatment. This significantly lengthens its duration and requires repeated intervention in the same anatomical zone.
Transplantation of blood-supplied tendon grafts. When a soft tissue defect is combined with a tendon defect, blood-supplying tissue complexes, including tendons, can be used.
For this, the dorsal flap of the foot, taken with the tendons of the long extensor of the II-V fingers, can be used. Tissue complexes from the outer surface of the thigh may include a wide fascia, flaps of which can replace tendon defects.
Transposition of tendons is one of the methods for replacing tendon defects, when a nearby tendon is used for this, the muscle of which can be switched to a new function without significant functional loss. Most often, one of the paired tendons adjacent to the defect zone is used (superficial and deep flexor tendons, common and intrinsic extensor of the II and V fingers).
IN AND. Arkhangelsky, V.F. Kirillov
