Biology 202 - Lecture 3

  1. Nervous System and Sense Organs
    • functions in obtaining information from the environment & coordinating body
    • information is transferred byelectrical signals, and is rapid and specific.activities
    • the basic units are neurons, whichinclude three types: sensory (receptor),motor (effector) and interneurons
  2. The vertebrate nervous system has two major components
    • central nervous system (info. processing)
    • peripheral nervous system (cranial and spinal nerves), including motor (ventral) and sensory nerves (dorsal)
  3. The peripheral nervous system in turn includes two parts:
    • a) the somatic system (bodywall & appendages)
    • b) the visceral or autonomic system, including two parts
    • i) the sympathetic system (“fightor flight”)
    • ii) the parasympatheticsystem
  4. The brain includes five basic sections
    • (i) telencephalon
    • (ii) diencephalon
    • (iii) mesencephalon
    • (iv) metencephalon
    • (v) myelencephalon
  5. (i) telencephalon
    • olfactory lobes
    • bulbs (olfaction)
    • cerebrum (voluntary movement)
    • corpus striatum (instinctive behaviour)
  6. (ii) diencephalon
    • thalamus (sensory relay)
    • hypothalamus (visceral integration)
  7. (iii) mesencephalon
    optic lobes or tectum(vision and visual reflexes)
  8. (iv) metencephalon
    • cerebellum(hearing/balance/orientation and motor coordination)
    • pons (co-ordination of cerebrum and cerebellum)
  9. (v) myelencephalon
    medulla oblongata(reflex centers for basic functions)
  10. receptors
    The nervous systems alsoincludes receptors for taste, smell, touch, etc
  11. multicellular sense organs
    • photoreception, including colour and UV
    • vision from the beginning, included: cornea, lens, iris, and retina
    • detection of orientation, motion and infrasound vibrations (inner ear semi circular canals, utricle, saccule)
    • via hair cells - cells with special cilia that detect motion in the extracellular fluid
  12. The Endocrine System
    • functions in communication and coordination
    • information transfer is slow & general, through chemicalsignals (hormones [internal] and pheromones [external]
    • includes endocrine (no ducts) and exocrine glands (ducts)
    • originally included only the pituitary ("master gland"),pineal (coordinates daily and seasonal rhythms) and thyroid (controls metabolism and homeostasis), plus scattered specialized cells
Card Set
Biology 202 - Lecture 3
Common Characteristics of Vertebrates