Answer to Question #330219 in Human Anatomy and Physiology for Jamie

Question

Describe the origin and structure of sympathetic and parasympathetic nerves and state three functions of each nerve. (10%- 5 for sympathetic and 5 for parasympathetic). ( short answer please)

Answer 1

Sympathetic nerves arise from intermediolateral nucleus of the lateral grey column of spinal cord, beginning at the first thoracic vertebra of the vertebral column and are thought to extend to the second or third lumbar vertebra. The Sympathetic nervous system consists of two sets of neurons – those that have their cell bodies within the spinal cord, and those whose soma resides in ganglia outside the central nervous system in paravertebral ganglions ( column). 

Functions: dilates pupils, increases heart rate and blood pressure , dilates bronchus.( just induced fight or flight response)

Parasympathetic neurons, which originate in the nodose ganglion of the vagus nerve or in dorsal-root ganglia at sacral levels S2–S4. In the parasympathetic nervous system, ganglia are located closer to, or sometimes within, the target organs. Some ganglia form large clusters called plexuses.

Function: constrict pupils and bronchus, decrease heart rate and blood pressure and relax muscles.