KAAP309 Lecture Notes - Lecture 10: Thoracic Splanchnic Nerves, Otic Ganglion, Paravertebral Ganglia
2 Mar 2016
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Effectors of ans: cardiac muscle, smooth muscle, glands: efferent pathways. Axons of ans are two-neuron chain: the preganglionic (first) neuron has a lightly myelinated axon and the ganglionic (second) neuron extends to an effector organ. Somatic motor neurons: heavily myelinated axons that extend from cns to an effector: target organ responses. Functions: innervate smooth and cardiac muscles and glands, make adjustments to ensure support for body activities, operate through subconscious control, have organs as most of their effectors, sympathetic division, parasympathetic division. Heart rate, metabolism, blood pressure increases and breathing is rapid. Skin is cold and sweaty and pupils dilate: anatomy: Origin of fibers: thoracic and high lumbar region of spinal cord. Length of fibers: short preganglionic and long postganglionic. Location of ganglia: close to spinal cord: sympathetic tone: keeps blood vessels in continual state of partial constriction. Increased activity of sympathetic fibers: causes blood vessel constriction and increase in bp.
