Ch. 23 - Construction of Neural Circuits (A+ Graded Already)

Growth cone correct answers the specialized end of a growing axon (or dendrite) that generates the motive forces for elongation - *See Fig. 23.1 (p. 509), Fig. 23.2 (p. 510), Fig. 23.3 (p. 511)* Lamellipodium correct answers a sheetlike extension, rich in actin filaments, on the leading edge of a motile cell or growth cone Filopodium correct answers slender protoplasmic projection, arising rom the growth cone of an axon or a dendrite, that explores the local environment Actin cytoskeleton correct answers regulates changes in lamellipodial and filopodial shape for directed growth Microtubule cytoskeleton correct answers responsible for the elongation of the axon itself Box 23A [*p. 512*] correct answers Choosing Sides: Axon Guidance at the Optic Chiasm Figure 23.4 [*p. 514*] correct answers Several families of ligands and receptors contitute the major classes of axon guidance molecules Extracellular matrix cell adhesion molecules correct answers first to be associated w/ axon growth [*p. 514*] - most prominent members: (a) *laminins* (b) *collagens* (c) *fibronectin* Integrins correct answers a family of receptor molecules found on growth cones that bind to cell adhesion molecules such as laminin and fibronectin Basal lamina correct answers a think layer of extracellular matrix material (primarily collagen, laminin, & fibronectin) that surrounds muscle cells and Schwann cells; also underlies epithelial sheets; also called basement membrane CAMs correct answers (along w/ cadherins) found on growing axons and growth cones as well as on surrounding cells and targets [*p. 514-516*] Cadherins correct answers a family of calcium-dependent cell adhesion molecules found on the surfaces of growth cones and the cells over which they grow Box 23B [*p.515-516*] correct answers Human Axon Guidance Disorders