What muscles are the muscles of the trunk? Muscles of the human body

To implement all kinds of movements in the human body, there are muscles that are divided into three main types. These are: skeletal, cardiac and smooth. Each has its own purpose and a different structure.

Appointment of muscles in the human body

The very first and main purpose of them in the body is to support bones and internal organs. The muscles completely cover the human body and carry the main goal - support and provision of motor functions. Every movement of our body provides muscle tissue, and it is not only the movement of the hands and feet, but the blinking, swallowing, processing and movement of food, the work of the heart. Without muscle tissue, the human body is not able to function.

The structure of the muscular corset

All the muscles of a person can be divided into groups, according to their purpose and location.

It is much easier to consider them in larger groups, for example, dividing them into three main groups. So, the muscles of the trunk are:

• Dorsal;
• Thoracic;
• Abdominal.

Torso muscles include dorsal surface and deep.

Superficial muscles of the back

Surface muscles are represented by:

• Trapezius muscle, attached to all the vertebrae of the thoracic region and its second end to the clavicle and scapula and is responsible for flexing the head. She is responsible for the movement of the scapula. The upper part raises, and the lower one lowers. With the retraction of the hands, the middle part of the muscle reduces the scapula closer to the spine. Also attached to the base of the skull and neck.
• The widest muscle of the back following the trapezium is attached to all the other parts of the spine of the lower part and to the vertebrae of the anterior thoracic cage, thus encompassing the entire body with a full turn. It is not only a corset for the human body, but it also attracts the shoulders and hands back, simultaneously turning them inward. It is one of those that belong to the "big muscles" group, because it is one of the largest in the whole body.
• The rhomboid muscles, both large and small, lie beneath the trapezius and are attached by their bundles to the lower cervical and grasp the 4 vertebrae of the thoracic region, and the other end are attached to the bone of the scapula and are responsible for its approach to the center.

• The muscle lifting the scapula is slightly higher, above the lozenge on the back of the neck. One end is attached to two cervical and two thoracic vertebrae, and the second part is fixed on the upper rib. This is a good holder for the neck, while lifting the scapula up.
• Lower and upper posterior jagged muscles. The lower one is located obliquely on the back and begins in the lumbar region, fastening to the first four lower ribs. It is responsible for lowering the edges. The upper is under the rhomboid and is attached to the upper ribs, starting from the 2nd to the 5th, with its other end holding onto the cervical vertebrae. Responsible for lifting ribs.

Deep back muscles

The muscles of the trunk are also the lateral with the medial, which are located on either side of the spinal column, stretching from the sacrum and to the occiput. The lateral are responsible for straightening the back and are superficial. The medial muscles are located at the very bottom relative to the others and consist of groups of small muscle bundles spilled across the spine. And also to these muscles are the belt muscles of the head and neck, participating in all movements and being a kind of corset.

Thoracic muscles

Muscles of the thoracic region can be divided into two groups, which include the upper muscles of the limbs and the shoulder girdle:

• The large pectoral muscle is the uppermost one, having a triangular shape and starting from the clavicle bone near the shoulder, joining the sternum from the 2nd to the 7th rib. The large pectoral muscle is responsible for the movement of the arm forward and inward, and also participates in raising the ribs on inspiration.
• The small pectoral muscle is located somewhat deeper and is attached at one end to the scapula, and the other to the ribs, from the 2nd to the 5th. Participates in its movement forward and downward, and, like the large one, is the lifter of the ribs on inspiration.
• Another representative of the small muscles is the subclavian. It is stretched between the clavicle and the upper right rib. Pulls it downward, thus fixing and holding.
• The anterior dentate muscle encircles the lateral surface of the thorax. One end is attached to the 9th rib, and the second - to the bottom corner of the blade edge. Pulls it forward, rotates. This is necessary for the movement of the hand above the horizontal position. Also, in teamwork with the diamond-shaped muscle, presses the shoulder blade tightly to the trunk.

Muscle breathing

The muscles of the trunk are also involved in breathing. External and internal intercostal muscles are located in the space between the ribs and are the main participants during inspiration and exhalation.

The diaphragm is the most unusually located flat muscle, which has a domed appearance. It is directed with the convex part upwards. By its action it is a piston pump, to perform the function of breathing. It is this muscle that squeezes and expands the lungs, forcing them to fill with air and release it. The diaphragm is attached along the whole perimeter of the chest. It is stretched to the ribs, the spine, the lower part of the chest.

Abdominal muscles

They are represented by five main ones, including the muscles of the press.

• The external oblique muscle is attached to the lower eight ribs, and from the rear to the iliac crest, thus, located under the large thoracic and to the level where the limb muscles, such as the femoral, quadriceps, and others begin to attach.
• The internal oblique muscle is located under the outer, starting from the lower rib, attaching to the lumbosacral fascia and inguinal ligaments, and behind - to the lower ribs. The oblique muscles serve as a corset for the internal organs of the abdominal cavity and are involved in flexion, extension and tilting, as well as bends in the trunk.
• The transverse muscle is located below the oblique and is attached to the lower ribs, starting from the 6th, and then to the lumbosacral fascia, the crest of the ilium and to the inguinal ligament.
• The rectus muscle of the abdomen lies outside and consists of 8 muscle bundles that pass into each other. They begin on the sternum and descend from the 5 ribs to the very bony bone. Their second name is the muscles of the press. The straight muscle is the main one when flexing and flexing the trunk in the forward direction.
• The square muscle of the lower back begins from the crest of the ilium and is attached to the lumbar spine, forming the posterior abdominal wall. It holds the muscular corset of the abdominal cavity. It participates in extension of the trunk back, as well as in bending forward.

The movement of muscles fills the body with life. Whatever a person does, all his movements, even those we sometimes do not pay attention to, are contained in the activity of muscle tissue. This is an active part of the musculoskeletal system, which ensures the functioning of its individual organs.