Lithium has an atomic number of 3 and a mass number of 7.
Which of the following is the number of protons in a lithium atom?

The hypothalamus is a region of the brain that synthesizes antidiuretic hormone (ADH), also known as vasopressin.

ADH is then transported to the posterior pituitary gland via neurohypophysial capillaries, where it is stored until it is ready to be secreted into the circulation.

Choice A. Pineal gland is not correct because it is a small endocrine gland located in the brain that secretes the hormone melatonin, which regulates sleep-wake cycles, but it does not synthesize ADH.

Choice B. Thymus is not correct because it is a gland located in the chest that produces hormones involved in immune system development, but it does not synthesize ADH.

Choice D. Pancreas is not correct because it is a gland located behind the stomach that secretes hormones such as insulin and glucagon, which regulate blood sugar levels, but it does not synthesize ADH.

The pleura is a double-layered serous membrane that covers each lung and lines the thoracic cage.

The pleura is a vital part of the respiratory tract.

Its role is to cushion the lung and reduce any friction that may develop between the lung, rib cage, and chest cavity.

Each pleura (there are two) consists of a two-layered membrane that covers each lung.

The layers are separated by a small amount of viscous (thick) lubricant known as pleural fluid.

The pleura is comprised of two distinct layers: the visceral pleura and the parietal pleura.

The visceral pleura is the thin, slippery membrane that covers the surface of the lungs and dips into the areas separating the different lobes of the lungs (called the hilum).