Neurology: Anatomy - Autonomic nervous system Flashcards
What is the role of the autonomic nervous system?
Subdivision of the motor nervous system that controls functions of the body not under conscious control
What are the two types of visceral nerve fibres and their roles?
- Visceral sensory fibres (general visceral afferent, GVA)
- Pain or subconscious visceral reflex sensations (e.g. information concerning distension, blood gas, BP) - Visceral motor fibres (general visceral efferent, GVE)
- Smooth (involuntary) muscle and glandular tissues
What are the three divisions of the ANS?
Sympathetic
Parasympathetic
Enteric (may also be considered part of the parasympathetic)
Compare and contrast the roles of the sympathetic and parasympathetic NS
Sympathetic: fight-or-flight responses
Parasympathetic: concerned with body conservation, often reversing the effective of sympathetic stimulation
Compare and contrast the distribution of the sympathetic and parasympathetic NS
Sympathetic: primarily regulates the blood vessels
Parasympathetic: distributed only to the viscera of the head, neck, and cavities of the trunk, and to the erectile tissues of the genitalia
Compare and contrast the location of presynaptic cell bodies in the sympathetic and parasympathetic NS
Sympathetic: presynaptic cell bodies are found only in the intermediolateral cell columns of gray matter in the thoracolumbar spinal cord, which are organised somatotopically
Parasympathetic: presynaptic cell bodies are found in the gray matter of the brainstem and sacral segments of the spinal cord
Where are the postsynaptic cells bodies of the parasympathetic NS found?
In or on the structure being innervated
In the head organised into discrete ganglia
Where are the postsynaptic cells bodies of the sympathetic NS found?
In sympathetic ganglia in the sympathetic trunks (paravertebral ganglia) or around the roots of the major branches of the abdominal aorta (prevertebral ganglia)
