List Anatomy – M
Myelin is a unique formation, the organization of which allows you to conduct an electrical impulse along the nerve fiber with minimal energy expenditure. Myelin sheath is a highly organized multilayer structure consisting of highly stretched and modified plasmatic membranes of Schwann's (in PNS) and oligodendroglial (in the central nervous system) cells.
The muscular muscle (m.supraspinatus) is located in the paranasal fossa. It begins on the back surface of the scapula above the scapula and on the supragastric fascia. The bundles extend laterally.
Muscles-rotators of the neck, chest and waist (mm. Rotatores cervicis, thoracis et lumborum) are located in the deepest layer of the musculature of the back, in the furrow between the spinous and transverse processes.
There are several well-defined muscles around the mouth opening. These muscles include the circular muscle of the mouth, the muscle that lowers the corner of the mouth, the muscle that lowers the lower lip, the chin and the buccal muscles, the muscle that lifts the upper lip, the small and large zygomatic muscles, the muscle that raises the corner of the mouth, and the muscle of laughter.
In the area of the nasal apertures there are several small, weakly developed muscles that widen or narrow these openings. This is the nasal muscle and the muscle that lowers the septum of the nose.
The eye slit is surrounded by bundles of the circular eye muscle, in which several parts are prominent. The circular muscle of the eye (m.orbicularis oculi) is flat, occupies the periphery of the orbit circumference, is located in the thickness of the eyelids, partially enters the temporal region. Lower tufts of muscle continue into the cheek area. The musculature consists of 3 parts: age-old, ocular and lachrymal.
The great diversity and freedom of hand movements as an organ of labor is ensured by the peculiarities of the structure of the joints of the upper limb, to which numerous muscles act.
Muscles of the body are divided into muscles of the back, chest and abdomen. The posterior regions of the trunk (regiones dorsales) encompass the entire posterior surface of the trunk. The upper back boundary is formed by the outer occipital protrusion and the superior occipital line of the occipital bone. The lower boundary is the level of the sacroiliac joints and the coccyx.
Among the muscles of the tongue, paired, striated, distinguish their own muscles and muscles, beginning on the bones of the skeleton (skeletal muscles). The native muscles of the tongue begin and end within the tongue, and the skeletal muscles have a bone beginning.
The deltoid muscle (m.deltoideus) is located superficially, directly under the skin, covers the shoulder joint from the lateral side, front, top and back, forms a characteristic roundness of the shoulder).
The muscles of the shoulder are divided into two groups according to the topographic and anatomical principle: the anterior (flexor) and the posterior (extensors). The anterior group consists of three muscles: the coracoid-brachial, the biceps arm muscle and the brachial muscle; the back is the triceps brachii muscle and the elbow muscle.
The muscles of the pelvis are divided into two groups - internal and external. The group of internal muscles include iliac-lumbar, internal blocking and pear-shaped.
Muscles of the larynx are functionally divided into muscles that stretch the vocal cords, expanders and narrowers of the glottis. All muscles of the larynx, except for the transverse anteral, paired.
The muscles of the head are divided into mimic and chewing muscles. Mimic muscles differ from the muscles of other areas of the human body in origin, attachment and functions. They develop on the basis of the second visceral arch, located under the skin and not covered with fascia.
Along with the tendons of the calf muscles, which form part of the anterior, posterior and lateral groups, attached to the bones of the foot, the foot has its own (short) muscles. These muscles begin and attach within the skeleton of the foot, have complex anatomical and topographical and functional relationships with the tendons of those leg muscles whose attachment points are on the bones of the foot.
The eyeball is attached six striated muscles: four straight - upper, lower, lateral and medial and two oblique - upper and lower. All straight muscles and the upper oblique begin at the depth of the orbit on the common tendon ring (anulus tendineus communis), fixed to the sphenoid bone and periosteum around the optic canal and partly on the edges of the upper globular fissure.
The skull of the skull is covered by a single muscular-anoneurotic formation - the supracerebral muscle (m.epicranius), in which the following parts are distinguished: occipular-frontal muscle; a tendon helmet (supracranial aponeurosis); temporomandibular muscle.
The muscles of the chest are arranged in several layers. More superficially lie those muscles that develop in connection with the laying of the upper limb. They connect the upper limb with the thorax. These include the large thoracic and anterior cog muscles.
Muscles of the back (musculi dorsi) are paired, occupying the entire dorsal side of the trunk, starting from the region of the sacrum and the adjacent parts of the iliac crests to the base of the skull. Being located layer by layer, these muscles have complex anatomical and topographical relations, due to the peculiarities of their development and function.
Muscles of the auricle are weak in man. Very rarely is the ability to move the auricle, which is combined with the simultaneous contraction of the occipitus-frontal muscle. There are anterior, upper and posterior ear muscles.