AUTONOMIC NERVOUS SYSTEM PHYSIOLOGY 💊
1. Using a table differentiate between the somatic Nervous System & the Autonomic
nervous system
Feature Somatic Nervous System Autonomic Nervous
(SNS) System (ANS)
Control Voluntary Involuntary
Pathway Structure Single neuron Two-neuron pathway
Neurotransmitter Acetylcholine Acetylcholine,
norepinephrine,
neuropeptides
Effector Organs Skeletal muscles Visceral organs
Function Conscious movement and Homeostasis and involuntary
reflex actions functions
2. What is the autonomic nervous system (ANS)?
Answer:
The autonomic nervous system (ANS) is a division of the peripheral nervous system
that controls involuntary bodily functions. It has two major divisions: the sympathetic
and parasympathetic nervous systems, which regulate organ system functions, and a
third division known as the enteric nervous system, which is located in the
gastrointestinal tract.
3. Differentiate between the sympathetic and parasympathetic divisions of the ANS.
Answer:
The sympathetic division originates from the thoracolumbar spinal cord and is
primarily responsible for the body's "fight or flight" response, preparing the body for
stressful situations. In contrast, the parasympathetic division originates from the brain
stem and sacral spinal cord and is responsible for "rest and digest" activities,
promoting relaxation and energy conservation.
4. What neurotransmitter do adrenergic neurons release, and what are their receptors
called?
Answer:
Adrenergic neurons release norepinephrine as their neurotransmitter. The receptors
for norepinephrine on the effector organs are called adrenoreceptors.
, 5. What is the role of cholinergic neurons, and what neurotransmitter do they release?
Answer:
Cholinergic neurons are responsible for releasing acetylcholine (ACh) as their
neurotransmitter. They play a crucial role in transmitting signals in both the
sympathetic and parasympathetic divisions of the autonomic nervous system.
6. How do the postganglionic neurons differ in the sympathetic and parasympathetic
divisions?
Answer:
Postganglionic neurons in the parasympathetic division are mostly cholinergic,
meaning they release acetylcholine. In contrast, postganglionic neurons in the
sympathetic division can be either adrenergic, releasing norepinephrine, or
cholinergic, depending on the specific target and function.
7. What does the term "nonadrenergic, noncholinergic" refer to?
Answer:
The term "nonadrenergic, noncholinergic" describes certain postganglionic
parasympathetic neurons in the gastrointestinal tract that release neurotransmitters
other than acetylcholine or norepinephrine, such as peptides (e.g., substance P) or
nitric oxide (NO).
8. What is the significance of the enteric nervous system within the autonomic nervous
system?
Answer:
The enteric nervous system is a third division of the autonomic nervous system that is
located in the plexuses of the gastrointestinal tract. It governs the function of the
gastrointestinal system independently, allowing for the regulation of digestive
processes without direct input from the sympathetic or parasympathetic divisions.
9. What are neuroeffector junctions?
Answer:
Neuroeffector junctions are the connections between postganglionic autonomic neurons and
their effectors, or target tissues. They function similarly to neuromuscular junctions in the
somatic nervous system but have distinct structural and functional characteristics.
10. Differentiate between neuroeffector junctions and neuromuscular junctions.
Answer:
1. Using a table differentiate between the somatic Nervous System & the Autonomic
nervous system
Feature Somatic Nervous System Autonomic Nervous
(SNS) System (ANS)
Control Voluntary Involuntary
Pathway Structure Single neuron Two-neuron pathway
Neurotransmitter Acetylcholine Acetylcholine,
norepinephrine,
neuropeptides
Effector Organs Skeletal muscles Visceral organs
Function Conscious movement and Homeostasis and involuntary
reflex actions functions
2. What is the autonomic nervous system (ANS)?
Answer:
The autonomic nervous system (ANS) is a division of the peripheral nervous system
that controls involuntary bodily functions. It has two major divisions: the sympathetic
and parasympathetic nervous systems, which regulate organ system functions, and a
third division known as the enteric nervous system, which is located in the
gastrointestinal tract.
3. Differentiate between the sympathetic and parasympathetic divisions of the ANS.
Answer:
The sympathetic division originates from the thoracolumbar spinal cord and is
primarily responsible for the body's "fight or flight" response, preparing the body for
stressful situations. In contrast, the parasympathetic division originates from the brain
stem and sacral spinal cord and is responsible for "rest and digest" activities,
promoting relaxation and energy conservation.
4. What neurotransmitter do adrenergic neurons release, and what are their receptors
called?
Answer:
Adrenergic neurons release norepinephrine as their neurotransmitter. The receptors
for norepinephrine on the effector organs are called adrenoreceptors.
, 5. What is the role of cholinergic neurons, and what neurotransmitter do they release?
Answer:
Cholinergic neurons are responsible for releasing acetylcholine (ACh) as their
neurotransmitter. They play a crucial role in transmitting signals in both the
sympathetic and parasympathetic divisions of the autonomic nervous system.
6. How do the postganglionic neurons differ in the sympathetic and parasympathetic
divisions?
Answer:
Postganglionic neurons in the parasympathetic division are mostly cholinergic,
meaning they release acetylcholine. In contrast, postganglionic neurons in the
sympathetic division can be either adrenergic, releasing norepinephrine, or
cholinergic, depending on the specific target and function.
7. What does the term "nonadrenergic, noncholinergic" refer to?
Answer:
The term "nonadrenergic, noncholinergic" describes certain postganglionic
parasympathetic neurons in the gastrointestinal tract that release neurotransmitters
other than acetylcholine or norepinephrine, such as peptides (e.g., substance P) or
nitric oxide (NO).
8. What is the significance of the enteric nervous system within the autonomic nervous
system?
Answer:
The enteric nervous system is a third division of the autonomic nervous system that is
located in the plexuses of the gastrointestinal tract. It governs the function of the
gastrointestinal system independently, allowing for the regulation of digestive
processes without direct input from the sympathetic or parasympathetic divisions.
9. What are neuroeffector junctions?
Answer:
Neuroeffector junctions are the connections between postganglionic autonomic neurons and
their effectors, or target tissues. They function similarly to neuromuscular junctions in the
somatic nervous system but have distinct structural and functional characteristics.
10. Differentiate between neuroeffector junctions and neuromuscular junctions.
Answer:
