Figure 1127

Schematic diagram comparing somatic efferent and visceral efferent neurons, a. In the somatic efferent (motor) system, one neuron conducts the impulses from the CNS to the effector (skeletal muscle), b. In the visceral efferent system (represented in this diagram by the sympathetic division of the ANS), a chain of two neurons conducts the impulses: a presynaptic neuron located within the CNS and a postsynaptic neuron located in the paravertebral or prevertebral ganglia. Moreover, each presynaptic neuron makes synaptic contact with more than one postsynaptic neuron. Postsynaptic sympathetic fibers supply smooth muscles (as in blood vessels) or glandular epithelium (as in sweat glands), c. Neurons of the ANS that supply organs of the abdomen reach these organs by way of the splanchnic nerves. In this example, the splanchnic nerve joins with the celiac ganglion, where most of the synapses of the two-neuron chain occur. Note that one presynaptic neuron makes contact with several postsynaptic neurons. (From Reith EJ, Breidenbach B, Lorenc M. Textbook of Anatomy and Physiology. St. Louis: CV Mosby, 1978.)

(Fig. 11.27b). Thus, there is a synaptic station in a ganglion outside the CNS, where a presynaptic neuron makes contact with postsynaptic neurons. Each presynaptic neuron synapses with several postsynaptic neurons.

The presynaptic neurons of the sympathetic division are located in the thoracic and upper lumbar portions of the spinal cord

The presynaptic neurons send axons from the thoracic and upper lumbar spinal cord to the vertebral and par avertebral ganglia. The ganglia in the paravertebral and vertebral sympathetic trunk contain the cell bodies of the postsynaptic effector neurons of the sympathetic division (Figs. 11.27b and 11.28).

The presynaptic neurons of the parasympathetic division are located in the brain stem and sacral spinal cord

The presynaptic parasympathetic neurons send axons from the brain stem, i.e., the midbrain, pons, and medulla, parasympathetic division of ans.

sympathetic division of ans.

Nerve Root Pain Symptoms

ciliary ganglion innervation via cranial outflow pterygopalatine ganglion otic ganglion lacrimal gland nasal, palatine, and pharyngeal glands , blood vessels of visceral structures, blood vessels, sweat glands, and arrector muscles of hairs submandibular ganglion cranial parasympathetic outflow

(via 4 cranial nerves)

parotid gland cephalic arterial ramus carotid periarterial plexus sublingual and i submandibular i glands i cardiopulmonary splanchnic nerves larynx trachea bronchi lungs larynx trachea bronchi lungs y liver V / gallbladder liver diaphragm gallbladder M a abdominopelvic splanchnic nerves stomach pancreas celiac ganglion stomach pancreas spleen aorticorenal ganglion left colic (splenic) flexure dividing sacral parasympathetic supply from cranial supply superior \

mesenteric ganglion large intestine small intestine rectum large intestine small intestine kidney suprarenal (adrenal) gland rectum internal anal sphincter sacral parasympathetic outflow (via pelvic splanchnic nerves)

inferior mesenteric ganglion innervation via sacral outflow bladder penis


bladder penis (clitoris) gonad sympathetic fibers parasympathe fibers presynaptic postsynaptic presynaptic postsynaptic

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