sympathetic root
(noun)
This carries postsynaptic sympathetic fibers that traverse the ganglion without crossing a synapse.
Examples of sympathetic root in the following topics:
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Parasympathetic (Craniosacral) Division
- Each has three roots entering the ganglion (motor, sympathetic, and sensory roots) and a variable number of exiting branches.
- The motor root carries presynaptic parasympathetic nerve fibers (general visceral efferent fibers) that terminate in the ganglion by creating a synapse for the postsynaptic fibers traveling to target organs.
- The sympathetic root carries postsynaptic sympathetic fibers (general visceral efferent fibers) that traverse the ganglion without creating a synapse.
- The sensory root carries general sensory fibers (general somatic afferent fibers) that also do not create a synapse in the ganglion.
- Because of its location, the parasympathetic system is commonly referred to as having craniosacral outflow, in contrast to the sympathetic nervous system, which is said to have thoracolumbar outflow.
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Autonomic Ganglia
- The two main categories are: sympathetic ganglia and parasympathetic ganglia.
- A dorsal root ganglion (or spinal ganglion) is a nodule on a dorsal root of the spine that contains the cell bodies of nerve cells (neurons) that carry signals from the sensory organs towards the appropriate integration center.
- The axons of dorsal root ganglion neurons are known as afferents.
- Sympathetic ganglia are the ganglia of the sympathetic nervous system.
- Sympathetic ganglia are the tissue from which neuroblastoma tumors arise.
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Function and Physiology of the Spinal Nerves
- The phrenic nerve arises from nerve roots C3, C4, and C5.
- The sympathetic division typically functions in actions that need quick responses.
- The functions of the parasympathetic and sympathetic nervous systems are detailed.
- This diagram indicates the formation of a typical spinal nerve from the dorsal and ventral roots.
- Numbers indicate the types of nerve fibers: 1 somatic efferent, 2 somatic afferent, 3–5 sympathetic efferent, 6–7 sympathetic afferent.
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Sympathetic Nervous System
- Sympathetic ganglia are the ganglia of the sympathetic nervous system that initiate fight-or-flight, stress-mediated responses.
- The sympathetic ganglia are the ganglia of the sympathetic nervous system (the red lines in the diagram below).
- This response is also known as the sympathetico-adrenal response because the pre-ganglionic sympathetic fibers that end in the adrenal medulla—like all sympathetic fibers—secrete acetylcholine.
- Sympathetic ganglia are the tissue from which neuroblastoma tumours arise.
- This intercostal nerve shows the sympathetic ganglion at the top left.
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Root Modifications
- There are many different types of specialized roots, but two of the more familiar types of roots include aerial roots and storage roots.
- Storage roots (for example, taproots and tuberous roots) are modified for food storage.
- Epiphytic roots are a type of aerial root that enable a plant to grow on another plant in a non-parasitic manner.
- The epiphytic roots of orchids develop a spongy tissue to absorb moisture and nutrients from any organic material on their roots.
- Other examples of modified roots are aerating roots and haustorial roots.
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Divisions of the Autonomic Nervous System
- The autonomic nervous system (ANS) contains two subdivisions: the parasympathetic (PSNS) and sympathetic (SNS) nervous systems.
- Sympathetic and parasympathetic divisions typically function in opposition to each other.
- The sympathetic division typically functions in actions requiring quick responses.
- Many think of sympathetic as fight or flight and parasympathetic as rest and digest or feed and breed.
- Distinguish between the parasympathetic and sympathetic subsystems of the autonomic nervous system
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Cervical Plexus
- There is anastomosis with the accessory nerve, hypoglossal nerve, and sympathetic trunk.
- There are two additional branches that are formed by the posterior roots of the spinal nerves:
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The Evolution of Roots in Seedless Plants
- A tap root system has a main root that grows down vertically from which many smaller lateral roots arise.
- In addition, some plants actually have a combination of tap root and fibrous roots.
- The tip of the root is protected by the root cap, a structure exclusive to roots and unlike any other plant structure.
- Aerial roots and prop roots are two forms of aboveground roots that provide additional support to anchor the plant.
- (a) Tap root systems have a main root that grows down, while (b) fibrous root systems consist of many small roots.
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Types of Root Systems and Zones of Growth
- Dicots have a tap root system, while monocots have a fibrous root system, which is also known as an adventitious root system.
- A tap root system has a main root that grows down vertically, from which many smaller lateral roots arise.
- Some plants have a combination of tap roots and fibrous roots.
- The tip of the root is protected by the root cap, a structure exclusive to roots and unlike any other plant structure.
- (a) Tap root systems have a main root that grows down, while (b) fibrous root systems consist of many small roots.
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Autonomic Interactions
- The sympathetic and parasympathetic autonomic nervous systems cooperatively modulate internal physiology to maintain homeostasis.
- Sympathetic and parasympathetic divisions typically function in opposition to each other.
- The sympathetic division typically functions in actions requiring quick responses.
- Consider sympathetic as fight or flight and parasympathetic as rest and digest or feed and breed.
- Some typical actions of the sympathetic and parasympathetic systems are listed below.