Classification of the Nervous System Brain Input to

Classification of the Nervous System

Brain (Input to CNS from periphery) Spinal cord (Output from CNS to periphery) Peripheral nervous system (PNS) Afferent division Sensory stimuli Central nervous system (CNS) Visceral stimuli Efferent division Somatic nervous system Motor neurons Autonomic nervous system Sympathetic nervous system Parasympathetic nervous system Smooth muscle Cardiac muscle Glands Effector organs (made up of muscle and gland tissue) Skeletal muscle

Classification We can divide the nervous system using many different sets of terminology… Anatomical Direction of Impulses Functional

Lets just keep it simple… Central Nervous System Peripheral Nervous System

Stimulus NS Response Input NS Output More complex features of the NS: intellect, consciousness, emotions, motivation, association, memory, language …….

Functions of the Nervous System 1. Sensory input – gathering information · To monitor changes occurring inside and outside the body (changes = stimuli) 2. Integration – · to process and interpret sensory input and decide if action is needed. 3. Motor output · A response to integrated stimuli · The response activates muscles or glands Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 1 a

Structural Classification of the Nervous System · Central nervous system (CNS) · Brain · Spinal cord · Peripheral nervous system (PNS) · Nerve outside the brain and spinal cord Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 2

Functional Classification of the Peripheral Nervous System · Sensory (afferent) division · Nerve fibers that carry information to the central nervous system Figure 7. 1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 3 a

Functional Classification of the Peripheral Nervous System · Motor (efferent) division · Nerve fibers that carry impulses away from the central nervous system Figure 7. 1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 3 b

Functional Classification of the Peripheral Nervous System · Motor (efferent) division · Two subdivisions · Somatic nervous system = voluntary · Autonomic nervous system = involuntary Figure 7. 1 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 3 c

Organization of the Nervous System Figure 7. 2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 7. 4

Central Nervous System:

Central Nervous System: Consists of Brain Located in cranial vault of skull Spinal cord Located in vertebral canal Brain and spinal cord Continuous with each other at foramen magnum

Peripheral Nervous System: comprises peripheral nerves (cranial & spinal) & ganglia Two subcategories Sensory or afferent (input) Motor or efferent (output) Divisions Somatic nervous system Autonomic nervous system (ANS) Sympathetic Parasympatheti c Enteric

PNS Cranial Nerves

PNS Spinal Nerves Ganglia