ORGANIZATION OF THE NERVOUS SYSTEM

NERVOUS SYSTEM ORCHESTRATES BODY FUNCTIONS TO MAINTAIN HOMEOSTASIS

•          IT MUST DETECT CHANGES IN AND AROUND THE BODY.

•          IT MUST PROCESS THE INCOMING SENSORY INFORMATION AND GENERATE AN APPROPRIATE MOTOR RESPONSE TO ADJUST ACTIVITY OF MUSCLES AND GLANDS.

•          ALL SENSORY AND MOTOR ACTIVITIES MUST BE ORCHESTRATED OR INTEGRATED TO ACHIEVE THE BALANCE OF HOMEOSTASIS.

THE NERVOUS SYSTEM IS DIVIDED INTO:

1. CENTRAL NERVOUS SYSTEM ( CNS )
2. PERIPHERAL NERVOUS SYSTEM ( PNS )

CNS

•          CONSISTS OF THE BRAIN AND THE SPINAL CORD

•          IS THE CONTROL CENTER OF NERVOUS SYSTEM INTERPRETING, INTEGRATING, AND ISSUING COMMANDS TO THE OTHER BRANCHES OF THE NERVOUS SYSTEM.

PNS

•          CONTAINS CRANIAL AND SPINAL NERVES AND SENSORY RECEPTORS THROUGHOUT THE BODY.

•          CAN BE DIVIDED ON A FUNCTIONAL BASIS INTO:

1. SENSORY DIVISION ( AFFERENT )

2. MOTOR DIVISION ( EFFERENT )

•          THE SENSORY DIVISION contains sensory receptors and nerves which carry information to the brain and spinal cord.

•          THE MOTOR DIVISION  sends information from the brain and spinal cord to the body´s effectors ( muscles and glands )

•          We divide Motor Division into two categories:

1. SOMATIC NERVOUS SYSTEM
2. AUTONOMIC NERVOUS SYSTEM

•          THE SOMATIC NERVOUS SYSTEM consists of nerves that carry information to skeletal muscles which control voluntary movement.

•          THE AUTONOMIC NERVOUS SYSTEM or VISCERAL M.S. consists of nerves that carry information to heart, visceral organs and glands. We don´t have voluntary control over these actions  ( so it´s involuntary !! )

THE AUTONOMIC N.S. IS SUBDIVIDED INTO:

•          SYMPATHETIC NERVOUS SYSTEM – HELP US TO GET AWAY FROM POTENTIALLY DANGEROUS SITUATIONS. ( fight or flight n.s. )

•          PARASYMPATHETIC NERVOUS SYSTEM – ITS EFFECTS WOULD BE OPPOSITE TO THOSE ON SYMPATHETIC N.S. ( rest n´digest n.s. )