Autonomic Nervous System Quiz

Autonomic Nervous System

• The autonomic nervous system (ANS) is responsible for involuntary functions
• It regulates organs and glands without conscious effort
• It's composed of two main divisions: sympathetic and parasympathetic
• The two divisions have opposite effects on target organs
• The sympathetic system is associated with "fight or flight" responses
• The parasympathetic system is associated with "rest and digest" responses
• Neurotransmitters are chemical messengers that transmit signals across synapses.

Autonomic Ganglia

• They are collections of nerve cells outside the central nervous system (CNS)
• Ganglia contain post-ganglionic neurons
• Ganglia act like relay stations
• Types of ganglia include lateral, collateral, and terminal

Lateral Ganglia

• Form part of the sympathetic chain
• Located on either side of the vertebral column
• Sites for relay of preganglionic sympathetic fibers

Collateral Ganglia

• Located in the abdomen near major arteries (aorta)
• Relay station for preganglionic sympathetic and some parasympathetic fibers

Terminal Ganglia

• Located near or on the wall of effector organs
• Relay station for preganglionic parasympathetic fibers

Functions of Autonomic Ganglia

• Relay stations for preganglionic nerves, providing signal transmission to postganglionic nerves
• Distributing centers for autonomic nerves
• Sites where drugs may act

Chemical Divisions of the ANS

• The ANS is separated into cholinergic and noradrenergic systems based on neurotransmitters
• Cholinergic system uses acetylcholine (ACh)
• Noradrenergic system releases noradrenaline (norepinephrine)

Acetylcholine (ACh)

• Principal neurotransmitter for all preganglionic fibers within the ANS
• Released by all preganglionic parasympathetic neurons
• Release by sympathetic post-ganglionic neurons innervating sweat glands and skeletal muscles

Norepinephrine (Nor-adrenaline)

• Main sympathetic post-ganglionic neurotransmitter (except for sweat glands and blood vessels)
• Released by most sympathetic post-ganglionic neurons

Adrenergic Receptors

• Types include alpha (α) and beta (β)
• Located in organs and tissues innervated by sympathetic post-ganglionic fibers
• Activated by noradrenaline

Cholinergic Receptors

• Includes muscarinic (M) and nicotinic (N) subtypes
• Muscarinic receptors are found on effector cells in parasympathetic responses
• Nicotinic receptors are present in autonomic ganglia

Origins and Types of Fibers

• Sympathetic fibers originate from thoracic and lumbar regions of the spinal cord
• Parasympathetic fibers originate from cranial and sacral segments
• Sympathetic fibers are typically short preganglionic and long postganglionic fibers
• Parasympathetic fibers are typically long preganglionic and short postganglionic fibers.

Test your knowledge on the autonomic nervous system, its functions, and the roles of autonomic ganglia. This quiz covers key concepts such as sympathetic and parasympathetic divisions, neurotransmitters, and different types of ganglia. Challenge yourself with questions about the body's involuntary responses and relay mechanisms.