Autonomic nervous system

What do Parasympathetic and sympathetic consist of after leaving the CNS?

After leaving the CNS, the parasympathetic and sympathetic nervous systems basically consist of - preganglionic nerve fibres - ganglion cells - postganglionic nerve fibres

Divisions and function of autonomic nervous system

The autonomic nervous system consists of three divisions - parasympathetic nervous system - sympathetic nervous system - enteric nervous system • The autonomic nervous system regulates functions which are largely outside of our voluntary control

Enteric Nervous System

• The enteric nervous system comprises the intrinsic nerve plexuses of the gastrointestinal tract. • Although it can function independently of the central nervous system, it is closely interconnected with the sympathetic and parasympathetic systems. • It is a complex system with local reflex pathways that can control some gastrointestinal function without external input.

Parasympathetic and sympathetic system

• The parasympathetic and sympathetic systems consist of nerves which arise in the central nervous system (CNS) and which innervate organs in the body (periphery) e.g. heart, blood vessels, gastrointestinal tract, bladder, exocrine glands • The parasympathetic and sympathetic systems cannot function without the central nervous system

Parasympathetic Nervous System

• The parasympathetic nerves leave the CNS from two separate locations • The cranial outflow consists of the cranial nerves III (oculomotor), VII (facial), IX (glossopharyngeal) and X (vagus) • The sacral outflow leaves through sacral segments 2 to 4 • The parasympathetic nervous system is sometimes called the craniosacral outflow

Differences between parasympathetic and sympathetic system

• The parasympathetic nervous system has long preganglionic nerves and short postganglionic nerves • The parasympathetic ganglia lie on, or close to the organs which are innervated • The sympathetic nervous system has short preganglionic nerves and long postganglionic nerves • The sympathetic ganglia generally lie in the sympathetic chain close to the spinal cord

Sympathetic Nervous System

• The sympathetic nerves leave the CNS from the thoracic and lumbar regions of the spinal cord • Thoracic segments T1 to T12 • Lumbar segments L1 and L2 (and L3?) • The sympathetic nervous system is sometimes called the thoracolumbar outflow