Chapter 12 - Nervous Tissue

Describe the organization of the nervous system

• CNS: Consists of brain and spinal cord

  • Spinal cord is connected to the brain through the foramen magnum of occipital bone

  • Source of thoughts, emotions and memories

• PNS: Consists of all nervous tissue outside the CNS

  • Nerves and sensory receptors (internal or external environment)

  • Divided into sensory (afferent) division and motor (efferent) division

How many cranial and spinal nerves are there

• 12 pairs of cranial nerves and 31 pairs of spinal nerves emerge from the spinal cord

In the PNS what is the role of the sensory (afferent) division

• Conveys input into the CNS from sensory receptors in the body

• Provides CNS with sensory information about the somatic senses and special senses

  • Somatic: tactile, thermal, pain, etc

  • Special: smell, taste, vision, hearing and equilibrium

In the PNS what is the role of the motor (efferent) division

• Conveys output from the CNS to effectors (muscles and glands)

• Further separated into somatic and autonomic nervous system