Sympathetic Nervous System Research Paper
The autonomic nervous system (ANS) consists of three main anatomical divisions: sympathetic, parasympathetic and enteric nervous systems. The sympathetic (SNS) and parasympathetic (PNS) systems provide a link between the central nervous system and peripheral organs.
The sympathetic nervous system originates in the spinal cord. Specifically, the cell bodies of the first neuron (the preganglionic neuron) are located in the thoracic and lumbar spinal cord. Axons from these neurons project to a chain of ganglia located near the spinal cord. In most cases, this neuron makes a synapse with another neuron (post-ganglionic neuron) in the ganglion. A few preganglionic neurons go to other ganglia outside of the sympathetic chain and synapse there. …show more content…
However, there is one exception: the sympathetic post-ganglionic neuron that terminates on the sweat glands uses acetylcholine.
The cell bodies of the parasympathetic nervous system are located in the spinal cord (sacral region) and in the medulla. In the medulla, the cranial nerves III, VII, IX and X form the preganglionic parasympathetic fibres. The preganglionic fibre from the medulla or spinal cord projects to ganglia very close to the target organ and makes a synapse. This synapse uses the neurotransmitter called acetylcholine. From this ganglion, the post-ganglionic neuron projects to the target organ and uses acetylcholine again at its terminal.
The two main neurotransmitters that operate in the autonomic system are acetylcholine and …show more content…
When this muscle contracts, it reduces the size of the pupil. This is the pupillary light reflex, which is an important test of brainstem function.
The ciliary ganglion is a parasympathetic ganglion located in the posterior orbit. It measures 1–2 millimeters in diameter and contains approximately 2,500 neurons. Preganglionic axons from the Edinger-Westphal nucleus travel along the oculomotor nerve and form synapses with these cells. The postganglionic axons run in the short ciliary nerves and innervate two eye muscles:
The sphincter pupillae constricts the pupil, a movement known as Miosis. The opposite, Mydriasis, is the dilation of the pupil.
The ciliaris muscle contracts, releasing tension on the Zonular Fibers, making the lens more convex, also known as
The sympathetic nervous system originates in the spinal cord. Specifically, the cell bodies of the first neuron (the preganglionic neuron) are located in the thoracic and lumbar spinal cord. Axons from these neurons project to a chain of ganglia located near the spinal cord. In most cases, this neuron makes a synapse with another neuron (post-ganglionic neuron) in the ganglion. A few preganglionic neurons go to other ganglia outside of the sympathetic chain and synapse there. …show more content…
However, there is one exception: the sympathetic post-ganglionic neuron that terminates on the sweat glands uses acetylcholine.
The cell bodies of the parasympathetic nervous system are located in the spinal cord (sacral region) and in the medulla. In the medulla, the cranial nerves III, VII, IX and X form the preganglionic parasympathetic fibres. The preganglionic fibre from the medulla or spinal cord projects to ganglia very close to the target organ and makes a synapse. This synapse uses the neurotransmitter called acetylcholine. From this ganglion, the post-ganglionic neuron projects to the target organ and uses acetylcholine again at its terminal.
The two main neurotransmitters that operate in the autonomic system are acetylcholine and …show more content…
When this muscle contracts, it reduces the size of the pupil. This is the pupillary light reflex, which is an important test of brainstem function.
The ciliary ganglion is a parasympathetic ganglion located in the posterior orbit. It measures 1–2 millimeters in diameter and contains approximately 2,500 neurons. Preganglionic axons from the Edinger-Westphal nucleus travel along the oculomotor nerve and form synapses with these cells. The postganglionic axons run in the short ciliary nerves and innervate two eye muscles:
The sphincter pupillae constricts the pupil, a movement known as Miosis. The opposite, Mydriasis, is the dilation of the pupil.
The ciliaris muscle contracts, releasing tension on the Zonular Fibers, making the lens more convex, also known as