torus

(noun)

the standard representation of such a space in three-dimensional Euclidean space; a shape consisting of a ring with a circular cross-section; the shape of an inner tube or hollow doughnut

Related Terms

Examples of torus in the following topics:

  • Pharynx

    • On the lateral walls of the nasopharynx are the pharyngeal ostia of the auditory tube, triangular shaped openings bound from behind by a firm prominence, the torus tubarius or cushion.
    • the salpingopharyngeal fold, a vertical fold of mucous membrane extending from the inferior part of the torus
    • the salpingopalatine fold, a smaller fold extending from the superior part of the torus to the palate

  • Pharynx

    • The lateral walls of the nasopharynx are made of the pharyngeal ostia (bone) of the auditory tube, and supported by the torus tubarus, a mound of cartilage tissue from the auditory tube.
    • The salpingopharyngeal fold is a vertical fold of mucous membrane extending from the inferior part of the torus and is made up of salpingopharyngeus muscle.
    • The salpingopalatine fold is a smaller fold extending from the superior part of the torus to the palate; it contains the levator veli palatini muscle.

  • Gastrulation

    • However, some common features of gastrulation across triploblastic organisms include: (1) A change in the topological structure of the embryo, from a simply connected surface (sphere-like), to a non-simply connected surface (torus-like); (2) the differentiation of cells into one of three types (endodermal, mesodermal, or ectodermal); and (3) the digestive function of a large number of endodermal cells.

  • Area of a Surface of Revolution

    • A circle that is rotated about a diameter generates a sphere, and if the circle is rotated about a co-planar axis other than the diameter it generates a torus.