Download Receptors and Neurotransmitters

Receptors and Neurotransmitters
Use the following terms to fill in the blanks in the paragraphs below (terms may be used
more than once):
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Beta
Dopamine
Epinephrine
Norepinephrine
Alpha
Muscarinic
Acetlycholine
Nicotinic
The existence of many types of neurotransmitters, the varied receptors available for
individual neurotransmitters, and different types of target cells bearing these receptors
enables neurotransmitters to induce a range of physiologic responses.
The preganglionic fibers of the sympathetic and parasympathetic divisions of the
autonomic nervous system (ANS) and a majority of the postganglionic fibers locate in the
parasympathetic nervous system secrete the neurotransmitter
Acetlycholine
. This neurotransmitter is involved in the control of skeletal muscle action in the central
nervous system (CNS) and the peripheral nervous system (PNS), stimulating skeletal
muscle contraction at neuromuscular junctions. It can excite or inhibit ANS synapses.
Most of the postganglionic fibers of the sympathetic division of the autonomic
nervous system secrete the neurotransmitter Dopamine
. In the CNS, this
neurotransmitter creates a sense of feeling good, but in low doses it can cause feelings of
depression. Depending on the receptor located in the PNS, this neurotransmitter can inhibit
or excite ANS actions.
Acetylcholine can combine with two different types of cholinergic receptors. The
first type is located in the membranes of effector cells at the ends of all postganglionic
parasympathetic nerve fibers and at the ends of cholinergic sympathetic nerve fibers. These
receptors are called Nicotinic
receptors, and they produce an excitatory response
that is relatively slow. Muscarinic
receptors are located in the synapses between the
preganglionic and postganglionic neurons of the parasympathetic and sympathetic
pathways and produce and excitatory response that is rapid.
The two major chemical mediators (hormones) of the sympathetic nervous system,
both of which are released by the adrenal glands, are Epinephrine and
Norepinephrine
.
Alpha receptors are one of the two major receptors
of the sympathetic nervous system and cause relaxation of uterine smooth muscle,
relaxation of bronchiole smooth muscles, and increased inotropy and chronotropy in the
heart when stimulated.
Dopamine
receptors are located in the brain. When stimulated, they create a
sense of feeling good. Ad efficiency of the neurotransmitters that stimulate the previously
mentioned receptors s associated with Parkinson’s’ disease. Paramedics use a synthetic
version of this neurotransmitter to treat patients who are suffering from cardiogenic shock.