Question

A. Describe parasympathetic and sympathetic neurons, taking into account the relative lengths of the fibers, neurotransmitters involved, and receptors that are present at the pre-post ganglionic junctions and postganglionic-target organ junctions (this does NOT include discussion of how the nerves exit the spinal cord).  

B. Name 5 effects of the flight-or-flight response and 5 effects that target DIFFERENT components than those named for the sympathetic effects of the rest-and-digest response.

Answer 1

The sympathetic nervous system activates what is known as fight and flight responses, There are two kinds of neuron involved in the transmission through the sympathetic nervous system, pre-ganglionic and post-ganglionic, The shorter preganglionic neurons originate in the thoracolumbar division of the spinal cord, while the post ganglionic is long and extends all over the body,  preganglionic neurons release acetylcholine as a neurotransmitter that activates nicotinic acetylcholine receptors on postganglionic neurons. postganglionic neurons release norepinephrine, which activates adrenergic receptors that are present on the peripheral target tissues. postganglionic fibers in the sympathetic division are allways adrenergic that means epinephrine and norepinephrine function as primary neurotransmitter, in both division of ANS postganglionic neuron express nicotonic acetylcholine receptors.

The parasympathetic nervous sytem are responsible rest and digest response, Nerve fibres of the parasympathetic nervous system arise from the central nervous system and have a cranialsacral outflow,  Specific nerves include several cranial nerves, . The axons of presynaptic parasympathetic neurons are usually long, extending from the CNS into a ganglion that is either very close to or embedded in their target organ. As a result, the postsynaptic parasympathetic nerve fibers are very short, parasympathetic neurons are cholinergic, that is to say acetylcholine is the primary neuro transmitter, like sympathetic nervous ssytem postganglionic nervous system also express nicotonic acetylcholine receptors.

Sympathetic preganglionic fibers tend to be shorter than parasympathetic preganglionic fibers because sympathetic ganglia are often closer to the spinal cord than are the parasympathetic ganglia

B) During flight or fight response, in response to stress the sympathetic nervous sytem is activated and certain hormones like epinephrine or cortisol is released, which in turn results in,

a) increase in heart rate.

b) increased blood pressure

c) dilation of pupils

d) rapid shallow breathing

e) increased sweating.

The sympathetic nervous system is responsible for regulating many homeostatic mechanisms in living organisms.provide physiological regulation over diverse body processes including pupil diameter, gut motility, and urinary output and can cause effects like blood flow to the surface of the body is reduced so that the blood flow to the arms, legs, shoulders, brain, eyes, ears and nose can be increased. Besides getting ready to run and fight, the body is preparing to think quickly and be aware of threats by hearing, seeing and smelling things better