Comparison of Somatic and Autonomic Nervous Systems

These flashcards cover key vocabulary and concepts related to the comparison of the somatic and autonomic nervous systems as presented in the lecture notes.

Somatic Nervous System (SNS)

Controls conscious processes, such as skeletal muscle movement and sensory perception.

Autonomic Nervous System (ANS)

Regulates involuntary processes to maintain homeostasis.

Parasympathetic Division

Part of the ANS that conserves energy and promotes 'rest-and-digest' functions.

Sympathetic Division

Part of the ANS that prepares the body for emergencies, known as 'fight-or-flight'.

Neuronal Convergence

A process where multiple preganglionic cells synapse on a single ganglionic cell.

Neuronal Divergence

A process where a single preganglionic cell synapses on multiple ganglionic cells.

Preganglionic Autonomic Motor Neuron

Transmits impulses to a ganglionic motor neuron.

Ganglionic Autonomic Motor Neuron

Transmits impulses to smooth muscle, cardiac muscle, and glands.

Myelinated Fibers

Fibers wrapped by Schwann cells, allowing for faster neural transmission through salutatory conduction.

Unmyelinated Fibers

Fibers shielded by a single Schwann cell that does not allow for salutatory conduction.

Craniosacral Division

Another name for the parasympathetic system, referring to its origin in the brainstem and sacral spinal cord.

Preganglionic Axons in Parasympathetic System

These axons are long with few branches and synapse close to the target organ.

Preganglionic Axons in Sympathetic System

These axons are short with many branches and synapse near the spinal cord.

Locations of Ganglia in Parasympathetic System

Parasympathetic ganglia are located near or within the effector organs.

Locations of Ganglia in Sympathetic System

Sympathetic ganglia are located near the spinal cord.

Cranial Nerves with Parasympathetic Fibers

Include CN III, CN VII, CN IX, and CN X.

Pelvic Splanchnic Nerves

Parasympathetic nerves originating from S2, S3, S4 that innervate pelvic organs.

Sympathetic Trunk

A chain of sympathetic ganglia located along either side of the vertebral column.

Collateral Ganglia

Congregations of sympathetic ganglia located anterior to the abdominal aorta.

Sympathetic Pathway

Includes spinal nerve, sympathetic nerve, splanchnic nerve, and adrenal medulla exit pathways.

Gray Rami Communicantes

Pathways connecting postganglionic fibers to spinal nerves.

Sympathetic Chain Ganglia

Include cervical, thoracic, lumbar, and sacral ganglia.

Splanchnic Nerve Pathway

Pathway where preganglionic fibers travel to prevertebral ganglia without synapsing.

Celiac Plexus

A major autonomic plexus that supplies the abdominal organs.

Dual Innervation

When organs receive signals from both the sympathetic and parasympathetic divisions.

Antagonistic Effects

Opposing actions of the sympathetic and parasympathetic systems on the same organ.

Cooperative Effects

When both divisions work together for a common overall effect.

Adrenal Medulla Pathway

Pathway where preganglionic fibers innervate adrenal medulla without synapsing.

Visceral Sensory Neuron

Detects stimuli within internal organs and transmits impulses to the CNS.

Cardiac Muscle

Type of muscle tissue that receives autonomic input from the ANS.

Smooth Muscle

Muscle tissue that responds to autonomic signals, regulating involuntary actions.

Schwann Cells

Cells that wrap around axons to form myelin sheaths.

Salutatory Conduction

Fast neural transmission due to the myelination of axons.

Pupil Control

Regulated by parasympathetic fibers from cranial nerve III.

Lacrimal Glands

Innervated by the parasympathetic fibers of cranial nerve VII.

Hormonal Response

Activates during the sympathetic 'fight-or-flight' response through the adrenal medulla.

S3-S4 Spinal Cord Segments

Originates parasympathetic fibers for pelvic organ innervation.

Visceral Organs innervation

Supplied by the nervous system to regulate functions like digestion.

Spinal Nerve Entry

Where sympathetic pathways merge back into the spinal nerve.

Hypogastric Plexus

An autonomic plexus that contributes to the innervation of pelvic organs.

Postganglionic Fiber Functions

Extend from ganglia to target organs, mediating responses.

Cranial Nerve IX

Innervates the parotid gland with parasympathetic fibers.

Plexuses

Networks of autonomic fibers that share pathways yet remain functionally distinct.

Somatic Nervous System Control

Conscious control over skeletal muscles and motor actions.

Visceral Sensory Inputs

Signals from internal organs detected by the ANS.

Homeostasis

The balance maintained by the autonomic system to keep the body's functions stable.

Short Preganglionic Axons

Characteristic of the sympathetic division leading to extensive branching.

Long Preganglionic Axons

Characteristic of the parasympathetic division, enabling localized effects.