The space in the thoracic cavity between the concave inner surfaces of the lungs, in which (in a special pericardial cavity) the heart is located, is called the mediastinum. The thoracic cavity is lined with a serous membrane called the pleura. The lungs are enclosed in the so-called pleural cavities, which are separate in man but communicate with one another in the majority of mammals. The shape of the thoracic cavity depends upon the shape of the thorax and the position of the diaphragm.
We sell 5 hammock sizes on the Traditional Hammocks (no spreader wood bars). Therefore, the length of the hammock is the same for each size but the difference is the width. Width gives the size. The larger the size, the wider and bigger the hammock.
Hammock: Like many other brands, Serac Hammocks are made of parachute nylon material and come with an attached stuff sack that makes it easy to stash and transport. A set of carbon steel carabiners attaches the hammock to the straps. Setup is simple and takes about a minute. Suspension: It also comes with a pair of six-foot long, one-inch wide polyester straps that wrap around the trees. Many companies sell straps separately from hammocks and they typically cost $30.