These are constantly opposing antagonists. Their counteraction is inherent in the nerve centers that control their activity. The centers of motion located in the brain of the head give out signals. They go to motoneurons, nerve cells located in the brain of the back, and then along the longest processes to the desired muscles.
The centers that send signals to antagonists are located in radically different states. When the flexor control center is stimulated, the extensor analog relaxes.
Flexors and extensors, work by straining. They move the whole body or some of its elements, doing dynamic work when running, walking or lifting objects. Static work is performed while maintaining a particular pose, holding the subject.
Both activities can be performed by the same musculature.
When they contract, they act like levers on bones. Each joint is moved by muscle mass attached to the sides. Which muscle is the flexor and which is the extensor depends on the situation.
When the arm is bent, the 2-headed muscle of the shoulder contracts, and the 3-headed muscle relaxes. Typically, extensor extensors are located at the back and flexors are located in front of the joint. Only in the ankle and knee joint are they attached in the reverse order.
There are also abductors that are outside the joint and take away one or another part of the body, and adductors that are inside and, conversely, lead. Muscles that lie transversely or obliquely relative to the vertical are rotated (instep - outward, pronators - inward).
Each movement is performed by a separate muscle group. Those of them that move in the same direction are synergists; on the contrary, they are antagonists. All groups work in concert, contracting and relaxing at the right time.
Nerve signals are responsible for triggering each muscle variety, traveling at a speed of two dozen impulses per second. Each of them has its own number of nerve endings. For example, there are a lot of them in the eyes, but few in the thigh. The connections of the cerebral cortex with muscle groups are also uneven. The sizes of the zones do not depend on the mass of the destination tissue, but on the complexity and subtlety of the resulting movements.
What is drying. Who is it shown to, how it differs from ordinary weight loss. The main principles of nutrition during this period. Many people who are far from sports often confuse the two goals of losing weight and drying the body. Here it may seem that in both the first and second cases, the process of achieving the goal will be similar. But this is not the case. Let's take a look at how to dry the legs and torso, how to remove fat for girls, is it possible to do this work in one week, and so on.
First, let's figure out why and who can set the task to dry the body, as well as remove excess fat. There are several options here:
But there are also people who don't need to dry:
Peeling hands can cause a lot of discomfort, both aesthetic and internal, as the skin becomes more vulnerable to external factors. A good remedy for dry skin of the hands is paraffin baths and wax masks, which can be made at home, if the necessary components are available, or from a master for a small amount. Special medicinal cosmetics, which are sold in pharmacies, have a quick, guaranteed safe effect. When choosing, you need to try each remedy on yourself and follow the instructions.
Creams made at home are natural and harmless, but they can be stored for a short time, up to 2 weeks, in some cases they can cause allergies if the composition is incorrectly selected. Beeswax, paraffin wax, fish or pork fat, butter and glycerin are well suited for the base of a homemade cream for dry skin. The product must contain essential oils and other natural emollients.
Cream for chapped hand skin is best applied at night for the best effect, to maximize hydration of the hands and prevent new cracks. Here are the homemade recipes you might need: