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.
Paragraphs need to be long enough to express any given idea (long enough to thoroughly explain the topic sentence). Research papers may call for paragraphs ten sentences or longer. The overall topic of the writing and content will determine the length of a paragraph. Unfortunately, there is no single number of sentences to a good paragraph.