Chapter 35 Integration and Control

Chapter 35 Integration and Control - Chapter 35 Integration...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 35 Integration and Control: Nervous Systems I. Introduction A. The more complex the life-style of an animal, the more elaborate are its modes of receiving, integrating, and responding to information in the external and internal worlds. B. These five points are basic to understanding nervous systems: 1 Reflexes are the simple, stereotyped movements that provide the basic operating machinery of nervous systems. 2 Cephalization is the evolutionary result of the layering of more and more nervous tissue over reflex pathways of ancient origin. 3 Brain regions allow more control over reflex actions and are the foundation for flexible, less stereotyped responses to stimulation. 4 In existing vertebrates, the oldest parts of the brain deal with reflex coordination, other parts deal with storage of information, and most recent layerings are the basis of memory, learning, and reasoning. 5 The coevolution of nervous, sensory, and motor systems was central to the development of more intricate behavior. II. Invertebrate Nervous Systems A. Nerve Nets 1 A network of sensory cells, nerve cells, and contractile epithelial cells makes up the nerve net in cnidarians. 2 The arrangement follows the radial symmetry of the cnidarian body. B. Bilateral, Cephalized Nervous Systems 1 Flatworms are the simplest animals with bilateral symmetry, which is reflected in their arrangement of muscles and nerves. a. The nervous system includes two longitudinal nerve cords, associated ganglia, and nerves. b. Some flatworms have a small brainlike clump of nervous tissue at the head end of the nerve cords. 2 Perhaps this arrangement evolved from the nerve net of cnidarian planula larvae. III. Vertebrate Nervous Systems A. How the System Developed 1 The vertebrate nervous system shows a shift from reliance on a notochord to reliance on a vertebral column and nerve cord.
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern