Mesoderm Dorsal

Dorsal mesoderm: structure and functions

Dorsal mesoderm, also known as parachordal mesoderm, is one of three types of mesoderm that plays an important role in embryonic development. It is located between the endoderm and ectoderm and extends along the length of the embryo, starting from the notochord organization zone and ending with the tail.

The structure of the dorsal mesoderm includes cells that differentiate into many different tissues, such as muscle, bone, cartilage, blood vessels and kidneys. These cells are also involved in the formation of the heart and blood vessels.

The dorsal mesoderm plays a key role in the development of the nervous system, especially in the formation of the neural tube. The neural tube is a precursor to the brain and spinal cord, and its formation depends on signals that come from the dorsal mesoderm.

In addition, the dorsal mesoderm plays an important role in establishing the body axis in the developing embryo. It acts as a support point for other tissues and cells that eventually form the rest of the body's organs and systems.

Disturbances in the development of the dorsal mesoderm can lead to serious pathologies and developmental defects, such as spinal hernias, abnormalities of the heart and blood vessels, and skeletal deformities.

In conclusion, the dorsal mesoderm is an important structure in embryonic development, playing a key role in the formation of muscle, bone, nervous and circulatory tissues. Its disturbances can lead to serious pathologies and developmental defects, so understanding its role and functions is important for the development of new methods of treatment and prevention of these diseases.

Dorsal mesoderms (from Latin *dorsalis* - rear, dorsal) - mesoderms located in the posterior section of the mesodermal body of dioecious chordates that parasitize vertebrates.

The body (the body together with the caudal end and the rear part of the head) in M. dorsalis is almost spherical in shape, the size of which can vary from 2-5 mm with an average length of 7 to 12 mm and a width of 3 to 5 mm. Such mesoderms have an anterior part of the body, which consists of a head lobe and an isthmus, which is its connecting section. The head contains lips and a very large pair of antennae; the lateral parts of the body are also evenly covered with small hairs. At the same time, the forelimbs (arms) are more developed and large. A mouth with three pairs of spongy tentacles is located on the anterior half of the head end. Under it, such individuals have about 18-24 gill slits, which “hang” outward (located on the sides of the oral part of the head).

Due to the presence of well-developed lateral pouches in M. dorsal, they also have 3 pairs of arms (non-shoulder pouches), as well as six pairs of well-developed legs, located in five pairs of pouchy pouches (perioscapular pouches) extending to the rear of the body. In this case, M. dorsal, primarily thanks to its fingers (they resemble cones), allows both squeezing out the egg and fertilizing it.