Trachea front and sides of the trachea to protect and maintain the airway. In front of the rings lies connective tissue and skin. Several other structures pass or sit over it; the jugular arch, which joins the two anterior jugular veins, sits in front of the upper part of the trachea. The sternohyoid and sternothyroid muscles stretch along its length, and the thyroid gland sits below this; with the isthmus of the gland overlying the second to fourth rings. The first tracheal ring is broader than the rest, and often divided at one end; it is connected by the cricotracheal ligament
What Is Intelligence? What Is Intelligence? What Is Intelligence?: Beyond the Flynn Effect is a book by psychologist James R. Flynn which outlines his model for an explanation of the eponymous Flynn effect. The book summarizes much of the work of Flynn in this area, as well as that of his colleague William Dickens of the Brookings Institution. The book begins with a description of what has generally become known as "the Flynn effect": the steady rise from one generation to the next in average scores on IQ tests over time. Flynn notes that this effect apparently contradicts some fundamental beliefs about IQ