Question

Mesothelium is
a. Lining of the coelom, which originated from mesoderm
b. Lining of coelom which originated from ectoderm
c. Lining of heart which originated from endoderm
d. Lining of heart which originated from mesoderm

Answer 1

The mesothelium is the layer of epithelial tissues surrounding the organs of the chest, abdominal cavity, and pelvis. It protects internal structures and helps in movement and breathing. It occurs in all serous membranes of the body and protects the membrane for any damage.

Complete answer:
Mesothelial cells develop as the mesoderm during development and play an important part in the development of the lung. It is a single, continuous layer of epithelial cells and is divided into three primary regions:

The pleura: It is two membranes that form a lining around the lungs. It is divided into the visceral pleura which lies directly over the lungs, and the parietal pleura, which is the outer layer of the lung lining.

The pericardium forms a lining around the heart and the mediastinum. These lines the abdominal cavity. It includes the mesentery that is divided into two layers. The visceral peritoneum that lines the internal organs, and the parietal peritoneum, which lines the abdominal and pelvic walls.

The mesothelium provides a slippery, non-stick surface and protects the organs of the chest and abdominal cavity during movement and breathing. It plays an important role in the homeostasis of the body by regulating the transport and movement of fluids and matter across the membrane from the outer side of the chest and abdominal cavities to the internal organs. Coagulation (blood clotting) and healing.

The mesothelium protects against infection as well as the spread of tumors. Active substances are secreted against bacteria by pleural mesothelial cells. It protects tumors by secreting substances that inhibit the growth of digestive tract tumors. The mesothelium is composed of an extensive monolayer of specialized cells that line the body's serous cavities and internal organs.

Mesothelium derives from the embryonic mesoderm cell layer, which lines the coelom (body cavity) in the embryo. The ectoderm is the outer layer of the body cavity. In diploblastic only 2 layers are present. The endoderm is the germ layer in early embryos that produces the gut tube and its derived organs. The heart is derived from mesodermal cells later it differentiates into endothelium, mesothelium, and myocardium.

Hence Mesothelium is the lining of the coelom, which originated from the mesoderm.
So, the correct answer is option (B).

Note: The mesothelium is derived from the embryonic mesodermal cell layer ling the coelom. It is mainly involved in the transport and movement of fluids across the serosal cavities and leukocyte migration in response to inflammatory response. It is composed of the squamous lining of body cavities and involved in providing protection. It provides slippery and non-adhesive surfaces and protects the organs.