The major glands of the endocrine system include the pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid gland, parathyroid gland, hypothalamus and adrenal glands. The hypothalamus and pituitary gland are neuroendocrine organs.
A newspaper lead (or lede if you prefer) can do its job in one sentence, but with few exceptions, a paragraph will contain more than one sentence. The OWL site, aimed at college students, suggests a length of from three to five or more sentences.
Most often, three to six sentences are regarded as good paragraphs in a classroom setting. This may be beneficial to help students identify when a new idea comes into play, and thus a new paragraph, but in reality there are no concrete amount of words or sentences that make a paragraph correct.