Central and Peripheral Nervous System Quiz

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Questions and Answers

What is the primary function of the sympathetic division of the autonomic nervous system?

Increases restful activities

Promotes energy conservation

Prepares the body for emergency situations (correct)

Stimulates gastrointestinal function

Which system is primarily responsible for voluntary muscle control?

Enteric nervous system

Central nervous system

Somatic nervous system (correct)

Autonomic nervous system

What term describes the balance between sympathetic and parasympathetic activity in organs?

Sympathetic dominance

Autonomic tone (correct)

Neural equilibrium

Autonomic activation

Which of the following best describes the role of the parasympathetic division?

Promotes 'rest and digest' activities Signup and view all the answers

Which part of the nervous system provides involuntary control over gastrointestinal functions?

Enteric nervous system Signup and view all the answers

What is the primary location of collateral ganglia in relation to the vertebral column?

Anterior Signup and view all the answers

Which ganglia supply the organs below the diaphragm?

All major collateral ganglia Signup and view all the answers

How many major collateral ganglia are there?

5 Signup and view all the answers

Which action is most associated with parasympathetic preganglionic neurons?

Innervating smooth muscle and glands in the walls of specific organs Signup and view all the answers

What is the role of the celiac plexus?

Surround the celiac trunk and supply multiple abdominal organs Signup and view all the answers

What is a consequence of an injury affecting the sympathetic outflow through the superior cervical ganglion?

Loss of sympathetic innervation leading to Horner's syndrome Signup and view all the answers

Which of the following describes the divergence of sympathetic preganglionic fibers?

They can synapse with more than 20 postganglionic neurons. Signup and view all the answers

Where do parasympathetic preganglionic fibers primarily originate?

Brain stem and sacral spinal nerves Signup and view all the answers

What effect occurs when sympathetic axons innervate smooth muscle in blood vessels?

Vasoconstriction Signup and view all the answers

Preganglionic axons that influence the adrenal medulla primarily release which hormones?

Epinephrine and norepinephrine Signup and view all the answers

Which cranial nerve is associated with the ciliary ganglion?

Oculomotor nerve (CN 3) Signup and view all the answers

Which has a more localized effect on organ function?

Parasympathetic division Signup and view all the answers

What characterizes the synaptic connection of parasympathetic postganglionic neurons?

They usually synapse with only 4 or 5 postsynaptic neurons. Signup and view all the answers

What defines the function of grey rami communicantes?

Provide sympathetic innervation to the skin and blood vessels Signup and view all the answers

What is the primary function of the sympathetic nervous system during physical or emotional stress?

Support functions that support vigorous physical activity Signup and view all the answers

Which of the following is a response associated with the parasympathetic nervous system?

Increased digestion Signup and view all the answers

The sympathetic division primarily innervates which of the following structures?

Sweat glands Signup and view all the answers

What effect does increased sympathetic tone have on blood vessels to the skeletal muscles?

Dilates blood vessels Signup and view all the answers

Which structure does NOT receive sympathetic innervation?

Lungs Signup and view all the answers

Which hormone is predominantly released by the autonomic nervous system during a stress response?

Norepinephrine (NE) Signup and view all the answers

What characterizes the fiber types of preganglionic and postganglionic neurons in the autonomic motor pathways?

Preganglionic neurons use Type B fibers; postganglionic use Type C fibers Signup and view all the answers

Which statement about the autonomic nervous system is accurate?

Emotions can influence the sympathetic division. Signup and view all the answers

Where do the preganglionic neurons of the sympathetic division originate?

In the lateral horns of gray matter at T1 to L2 Signup and view all the answers

What describes the response of blood vessels to the kidneys during sympathetic activation?

Constrict Signup and view all the answers

What is the primary role of the autonomic ganglia in the autonomic nervous system?

They are where preganglionic and postganglionic neurons synapse. Signup and view all the answers

Which neurotransmitters can autonomic motor neurons release?

Acetylcholine or norepinephrine Signup and view all the answers

What defines the primary response of the parasympathetic division?

Promotes energy conservation and restoration Signup and view all the answers

Study Notes

Central Nervous System (CNS)

The CNS comprises the brain and spinal cord.

Peripheral Nervous System (PNS)

The PNS is outside the CNS.
It has three divisions: Somatic Nervous System (SNS), Autonomic Nervous System (ANS), and Enteric Nervous System (ENS).

Somatic Nervous System (SNS)

Part of the PNS.
Controls voluntary movements.
Connects sensory receptors to skeletal muscles.

Autonomic Nervous System (ANS)

Part of the PNS.
Controls involuntary functions.
Connects sensory receptors in visceral organs to smooth muscle, cardiac muscle, and glands.
Has two divisions: Sympathetic and Parasympathetic.

Sympathetic Nervous System

"Fight or flight" response.
Increases alertness and metabolic activities to prepare for emergencies.
Increases heart rate, blood pressure, and blood flow to skeletal muscles.
Decreases blood flow to non-essential organs like the GI tract.

Parasympathetic Nervous System

"Rest and digest" response.
Conserves energy and promotes restorative activities.
Primarily targets the GI tract and respiratory tract.
Decreases heart rate and blood pressure.

Enteric Nervous System (ENS)

Involuntary system within the GI tract.
Monitors chemical changes and distension in the GI tract.
Controls smooth muscle activity within the GI tract.

Autonomic Tone

The balance between sympathetic and parasympathetic activity.
Regulated primarily by the hypothalamus.
Some organs receive only sympathetic innervation (e.g., sweat glands, blood vessels).

Sympathetic Responses

Dominates during stress.
Favors activities supporting physical exertion (e.g., increased blood flow to skeletal/cardiac muscle, glycogenolysis).
Associated with emotions (fear, rage, embarrassment).
Examples include dilation of pupils, increased heart rate/blood pressure, and bronchodilation.

Parasympathetic Responses

Dominates during rest.
Supports energy conservation and restorative functions.
Examples include decreased heart rate, bronchoconstriction, and pupil constriction.

Comparison: Somatic vs. Autonomic

Somatic NS involves one neuron pathway; Autonomic NS involves two neuron pathways.
Somatic NS is voluntary; Autonomic NS is involuntary.
Somatic NS targets skeletal muscle; Autonomic NS targets smooth muscle, cardiac muscle, and glands.
Somatic NS uses acetylcholine as a neurotransmitter; Autonomic NS may use acetylcholine or norepinephrine.

Anatomy of Autonomic Motor Pathways

Consists of preganglionic and postganglionic neurons and an autonomic ganglion.

Preganglionic Neuron

First neuron in the pathway.
Located in the CNS.
Typically a type B fiber.
Synapses with a postganglionic neuron (in a ganglion)
Can synapse with adrenal medulla cells.

Postganglionic Neuron:

Second neuron.
Located in the PNS (autonomic ganglion)
Has a type C fiber.
Targets the visceral effector.

Autonomic Ganglia

Synapse point of pre- and post-ganglionic neurons.
Sympathetic ganglia include paravertebral and prevertebral ganglia.
Parasympathetic ganglia are often called terminal ganglia.

Sympathetic Ganglia

Paravertebral ganglia (sympathetic trunk ganglia): Form a chain alongside the vertebral column.
Innervate organs above the diaphragm.
Include superior, middle and inferior cervical ganglia
Prevertebral ganglia (collateral ganglia): Lie anterior to the vertebral column. Innervate organs below the diaphragm. Include celiac, superior mesenteric, inferior mesenteric, aorticorenal, and renal ganglia.

Parasympathetic Ganglia

Terminal ganglia: Located near or within the visceral organ.
Have specific ganglia in the head, e.g., ciliary, pterygopalatine, submandibular, and otic ganglia.

Connections of Sympathetic Preganglionic Neurons

Synapse in the first ganglion encountered (paravertebral).
May ascend or descend to a different ganglion.
May synapse in a prevertebral ganglion (via splanchnic nerves).
May reach adrenal medullae.
Show divergence, with one preganglionic neuron affecting many postganglionic neurons.

Connections of Parasympathetic Preganglionic Neurons

Synapse in terminal ganglia near or within the visceral effector.
Typically synapse with a small number of postganglionic neurons.
Result in localized responses.

Autonomic Plexuses

Network of sympathetic and parasympathetic axons with sensory neurons. Found in thorax, abdomen, and pelvis.
Examples: Cardiac plexus (heart), pulmonary plexus (lungs), celiac (solar) plexus (stomach, spleen, pancreas), superior mesenteric, inferior mesenteric, hypogastric, and renal plexuses.

Connections - Sympathetic Postganglionic Neurons and Visceral Effectors

Enter spinal nerves via grey rami communicantes, providing innervation to structures in skin and blood vessels.
Some axons travel along arteries (cephalic periarterial nerves) supplying visceral effectors in the head and part of the neck.
Sympathetic nerves extend to visceral effectors in the thorax.

Innervation of Adrenal Medullae

Preganglionic sympathetic axons reach chromaffin cells in the adrenal medullae (modified sympathetic ganglia).
These cells secrete epinephrine and norepinephrine into the bloodstream (hormones).

Horner's Syndrome

Sympathetic innervation loss (typically in the superior cervical ganglion).
Symptoms include ptosis, miosis, anhydrosis, and enophthalmos.

Structure of Parasympathetic Division

Cranial outflow originates from nuclei in the brainstem, primarily through the vagus nerve.
Ganglia include ciliary, pterygopalatine, submandibular, and otic ganglia.
Sacral outflow originates from S2-S4 spinal nerves, forming pelvic splanchnic nerves which synapse in terminal ganglia near target organs.

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Description

Test your knowledge on the Central and Peripheral Nervous Systems, including their structures, functions, and key divisions. This quiz will cover the Somatic, Autonomic, and Enteric Nervous Systems, along with their roles in voluntary and involuntary actions.