a thin piece of wood or other rigid material used to immobilize a fractured or dislocated bone, or to maintain any part of the body in a fixed position. 2. one of a number of thin strips of wood woven together to make a chair seat, basket, etc.
If you take a close look at epithelial cells using a microscope, you will see them tightly packed together. This helps make a protective barrier for our bodies. There are also some special door-like connections between each epithelial cell called gap junctions. The gap junctions are where the cells exchange nutrients.
The lungs occupy most of the space in the thoracic cavity. The heart sits between the right and left lung. The lungs are soft and spongy because they are mostly air spaces surrounded by the alveolar cells and elastic connective tissue. Each lung is enclosed by a double-layered serous membrane, called the pleura.The visceral pleuron is firmly attached to the surface of the lung. Visceral pleura is continuous with the parietal pleura that lines the wall of the thorax. The small space between the visceral and parietal pleurae is the pleural cavity.he lungs occupy most of the space in the thoracic cavity. The heart sits between the right and left lung. The lungs are soft and spongy because they are mostly air spaces surrounded by the alveolar cells and elastic connective tissue. Each lung is enclosed by a double-layered serous membrane, called the pleura.