The Peripheral and Autonomic Nervous System Chapter 9 The Peripheral and Autonomic Nervous System

Peripheral Nervous System Nerves that connect the brain and spinal cord with sensory receptors, muscles, and glands Two subcategories Afferent peripheral system Consists of afferent or sensory neurons that convey information from receptors in the periphery of the body to the brain and spinal cord Efferent peripheral system Consists of efferent or motor neurons that convey information from the brain and spinal cord to the muscles and glands

Efferent Peripheral System Somatic nervous system Autonomic nervous system Sympathetic Stimulates or speeds up activity and thus requires an energy expenditure and uses norepinephrine as a neurotransmitter Fight-or-Flight System Parasympathetic Most active under ordinary, relaxed conditions Rest-and-Repose System (energy-conserving system)

Nerves Bundles of nerve fibers enclosed by connective tissue Sensory or afferent nerves Motor or efferent nerves Mixed nerves

Cranial and Spinal Nerves Part of the peripheral nervous system 12 pairs of cranial nerves 31 pairs of spinal nerves

Cranial Nerves I (Olfactory) II (Optic) III (Oculomotor) IV (Trochlear) V (Trigeminal) VI (Abducens) VII (Facial) VIII (Vestibulocochlear) IX (Glossopharyngeal) X (Vagus) XI (Spinal accessory) XII (Hypoglossal)

Spinal Nerve Plexus Cervical plexus Brachial plexus Lumbar plexus Sacral plexus

Autonomic Nervous System Nerves, ganglia, and plexuses which carry impulses to all smooth muscle, secretory glands, and heart muscle Two divisions Sympathetic system Parasympathetic system Both are strongly influenced by emotion

Reflex Act Simplest type of nervous response Unconscious and involuntary Reflexive acts Stimulus Change in the environment Receptors Sensory nerve that receives a stimulus and transmits it to the CNS Response Reaction to a stimulus Reflex actions, or autonomic reflexes, involving the skeletal muscles are controlled by the spinal cord

Biofeedback Measurement of physiological responses Yields information about the relationships between the mind and the body Can learn to manipulate these responses through mental activity