Narcissists believe their personality and appearance is superior to others. Symptoms of narcissism include focusing only on one's self, lacking guilt and an inability to empathize. Narcissistic people tend to be vain. A marriage being undermined by narcissism might benefit from therapy.
Trocar: A sharply pointed shaft, usually with a three-sided point. A trocar may be used within a cannula, a hollow tube, designed to be inserted into a vein, artery, bone marrow or body cavity. The word trocar is derived from the French trois (three) + carre (side). Last Editorial Review: 6/9/2016.
Tracheid. a dead lignified plant cell that functions in water conduction. Tracheids are found in the xylem of all higher plants except certain angiosperms, such as cereals and sedges, in which the water-conducting function is performed by vessels, or tracheae.Tracheids are usually polygonal in cross section; their walls have annular, spiral, or scalene thickenings or rimmed pores.racheids are found in the xylem of all higher plants except certain angiosperms, such as cereals and sedges, in which the water-conducting function is performed by vessels, or tracheae. Tracheids are usually polygonal in cross section; their walls have annular, spiral, or scalene thickenings or rimmed pores.