Exercise 27 Autonomic Nervous System

Anatomical differences between the sympathetic and parasympathetic divisions of the ANS.

- come from different regions of the cns: parasympathetic = craniosacral, sympathetic = thoracolumbar - locations of ganglia: parasympathetic = close to target organs, sympathetic = close to spinal cord - different lengths of post-ganglionic fibers and branching.

List the names and numbers of the four cranial nerves that the parasympathetic division of the ANS arises from.

Cranial nerves III (oculomotor), VII (facial), IX (glossopharyngeal), and X (vagus)

Based on this brief exposure to a polygraph, explain why this might not be an exact tool for testing the sincerity and honesty of a subject. Refer to your data to support your conclusions.

It is not possible to state with certainty that every subject who lies will have an absolutely predictable autonomic nervous system response. For this reason, although GSR is useful as an investigative tool, it is not accepted as an exact measurement tool.

List the names of the two motor neurons of the autonomic nervous system.

Preganglionic neuron and postganglionic neuron

Which branch of the ANS is dominant during a galvanic skin response? Describe the physiological basis of this response.

SNS; sweat gland activity increases.

Physiological effects of the sympathetic and parasympathetic divisions.

Some organs have opposing actions. Salivary glands are activated by both systems.

List two types of sympathetic ganglia that contain postganglionic cell bodies.

Sympathetic trunk ganglia and collateral ganglia

List two types of parasympathetic ganglia that contain postganglionic cell bodies.

Terminal ganglia and intramural ganglia

Describe exactly how, from a physiological standpoint, EDA/GSR can be correlated with activity of the autonomic nervous system.

The autonomic nervous system controls sweat glands of the skin. Increased moisture on the skin decreases its electrical resistance, which can be recorded.

Which part of the rami communicants contains nonmyelinated fibers

The gray ramus communicants contains nonmyelinated fibers (axons).

Ogilvie syndrome is a condition that mimics a bowel obstruction. The patient experiences abdominal bloating and constipation in the absence of a mechanical blockage. Ogilvie syndrome is usually preceded by surgery and results in extreme loss of motor activity in the bowel. Which division of the ANS is underactive in this case, especially with respect to the gastrointestinal system?

The parasympathetic division.

Neostigmine is a drug that is classified as an acetylcholinesterase inhibitor. Explain how neostigmine could reverse the effect of Ogilvie syndrome.

The smooth muscle of the digestive tract is stimulated by the neurotransmitter ACh. By blocking AChE, you allow more build-up of ACh in the synaptic cleft, thereby increasing stimulation of the gastrointestinal tract.

Galvanic skin response (electrodermal activity)

a change in the electrical resistance of the skin caused by emotional stress, measurable with a sensitive galvanometer, e.g. in lie-detector tests.

Autonomic Nervous System

a subdivision of the peripheral nervous system. Controls INVOLUNTARY ACTIVITY of visceral muscles and internal organs and glands.

Somatic Nervous System

a subdivision of the peripheral nervous system. Enables VOLUNTARY actions to be undertaken due to its control of skeletal muscles

Sympathetic Trunk (Term)

nerve running along each side of the vertebral column

Preganglionic neuron

the first neuron in a series that transmits impulses from the CNS

Postganglionic neuron

the second neuron in a series that transmits impulses from the CNS