What would be the best explanation for why myelinated fibers conduct signals faster than unmyelinated fibers?
A) Diffusion of ions along the axoplasm is faster.
B) There are no internodes in unmyelinated fibers.
C) There are more internodes in unmyelinated fibers.
D) Facilitated diffusion of sodium and potassium is faster in myelinated fibers.
E) Active transport of sodium and potassium is faster in myelinated fibers.
A
You might also like to view...
Chewing
a. grinds and breaks up food b. mixes food with saliva to facilitate swallowing c. reflexively increases salivary and gastric secretions d. reflexively increases pancreatic and bile secretions e. does all of the above
Communication between cells is key to organism-level regulation of the internal environment to maintain health, that is, nearly constant internal conditions (homeostasis). Outline and compare the intercellular communication pathways that function to
provide homeostasis. What will be an ideal response?
Hormones are intercellular chemical signals that
A. are secreted into the external environment where they act. B. affect only non-hormone producing organs or tissues. C. help coordinate growth, development and reproduction. D. operate primarily by positive feedback.
Choose the term that does not belong
A. glomerulus B. macula densa C. juxtaglomerular cells D. juxtaglomerular apparatus E. afferent arteriole