What is a Somite in medicine?

What is a Somite in medicine?

[so´mīt] one of the paired segments along the neural tube of a vertebrate embryo, formed by transverse subdivision of the thickened mesoderm next to the midplane, that develop into the vertebral column and muscles of the body.

What makes up a Somite?

Somite formation begins as paraxial mesoderm cells become organized into whorls of cells called somitomeres. The somitomeres become compacted and bound together by an epithelium, and eventually separate from the presomitic paraxial mesoderm to form individual somites.

What is Somite period?

Anatomical terminology. The somites (outdated term: primitive segments) are a set of bilaterally paired blocks of paraxial mesoderm that form in the embryonic stage of somitogenesis, along the head-to-tail axis in segmented animals.

What is the difference between somitomeres and somites?

is that somitomere is in the developing vertebrate embryo, one of the loose masses of paraxial mesoderm derived cells that form along each side of the neural tube towards the end of the third gestational week while somite is (embryology) one of the paired masses of mesoderm distributed along the sides of the neural ...

What are occipital somites?

Occipital somites (1-5 in human) fuse at an early stage of embryonic development and do not contribute to segmented skeletal structures. They incorporate into the occipital area of embryonic skull, give rise to the tongue muscles and also condense to contribute to the basi-occipital and exo-occipital cartilages.

Are somites epithelial?

Somites bud off sequentially and rhythmically from the mesenchymal 'paraxial' mesoderm, arising as pairs of epithelial spheres that flank the neural tube and accumulate in a progressive A-P direction. ... Together with cells from the midline notochord, the sclerotome differentiates into the vertebral column.

Does notochord become spine?

The notochord also plays a crucial role in the structure of a developing embryo. As it is the precursor to the spine, it can be thought of as a transient spine of the embryo, while the actual spinal cord develops from the neural tube [31]. The structure of the notochord resembles that of a stiff, yet flexible rod.

What is the function of occipital somites?

Occipital somites (1-5 in human) fuse at an early stage of embryonic development and do not contribute to segmented skeletal structures. They incorporate into the occipital area of embryonic skull, give rise to the tongue muscles and also condense to contribute to the basi-occipital and exo-occipital cartilages.

What do somitomeres do?

Somitomeres also contribute to cranial skeleton, and to dermis and meninges. Somitomeres thus make similar contributions in the head that somites make in the trunk. (Couly et al. (25) contend that somitomeres do not contribute to dermis.)

What do somitomeres become?

In the trunk and tail, somitomeres gradually condense and epithelialize to become somites.

What is the meaning of somites?

• Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia. one of the paired segments along the neural tube of a vertebrate embryo, formed by transverse subdivision of the thickened mesoderm next to the midplane, that develop into the vertebral column and muscles of the body. Somites in a 22-day embryo.

What are the components of somitogenesis?

• The important components of somitogenesis (somite formation) are periodicity, epithelialization, specification, and differentiation. The first somites appear in the anterior portion of the trunk, and new somites “bud off” from the rostral end of the paraxial mesoderm at regular intervals (Figures 14.2C,D and 14.3).

What is the pre-somitic fate of the mesoderm?

• The pre-somitic mesoderm commits to the somitic fate before mesoderm becomes capable of forming somites. The cells within each somite are specified based on their location within the somite.

What are somitomeres in the paraxial mesoderm?

• As cells within the paraxial mesoderm begin to come together, they are termed somitomeres, indicating a lack of complete separation between segments. The outer cells undergo a mesenchymal–epithelial transition to form an epithelium around each somite. The inner cells remain as mesenchyme .