BIOL 252 Human Anatomy & Physiology II (Lab):
Module 4 Exam Review – 82 Q&A (Portage
Learning, LockDown
**SECTION I: AUTONOMIC NERVOUS SYSTEM OVERVIEW AND COMPARISON
WITH SOMATIC NERVOUS SYSTEM (Questions 1-15)**
1. Define the autonomic nervous system and explain its primary function.
Answer: The ANS is the division of the peripheral nervous system that regulates
involuntary visceral functions including heart rate, blood pressure, digestion, and
glandular secretion to maintain homeostasis.
2. Compare the number of neurons in the efferent pathway between the somatic
nervous system and the ANS.
Answer: Somatic NS uses a single motor neuron from CNS to skeletal muscle. ANS
uses a two-neuron chain consisting of a preganglionic neuron and a postganglionic
neuron.
3. Differentiate between visceral sensory neurons and somatic sensory neurons.
Answer: Visceral sensory neurons monitor internal conditions such as stretch, chemical
changes, and temperature in organs. Somatic sensory neurons monitor external stimuli
and skeletal muscle proprioception.
4. Explain why the ANS is considered both afferent and efferent.
Answer: Visceral afferent fibers carry sensory information from organs to the CNS, while
visceral efferent fibers carry motor commands from the CNS to smooth muscle, cardiac
muscle, and glands.
, 5. Describe the two major divisions of the ANS and their anatomical origins.
Answer: Sympathetic division arises from thoracolumbar spinal cord (T1-L2).
Parasympathetic division arises from craniosacral regions (cranial nerves III, VII, IX, X
and S2-S4).
6. Define dual innervation and explain its functional significance.
Answer: Most visceral organs receive input from both sympathetic and parasympathetic
divisions. This allows fine-tuned antagonistic control of organ activity.
7. Identify organs that receive only sympathetic innervation.
Answer: Adrenal medulla, sweat glands, arrector pili muscles, most blood vessels, and
the kidney receive predominantly sympathetic innervation.
8. Explain the concept of autonomic tone.
Answer: The background level of ANS activity that maintains resting organ function.
Parasympathetic tone usually predominates in the heart and digestive tract at rest.
9. Compare the length of preganglionic fibers in the sympathetic versus
parasympathetic divisions.
Answer: Sympathetic preganglionic fibers are short. Parasympathetic preganglionic
fibers are long because ganglia are located near or within target organs.
10. Describe the location of sympathetic chain ganglia versus collateral ganglia.
Answer: Sympathetic chain (paravertebral) ganglia lie alongside the vertebral column.
Collateral (prevertebral) ganglia lie anterior to the vertebral column in the abdomen.
11. Explain the functional role of the adrenal medulla within the sympathetic nervous
system.
Answer: The adrenal medulla functions as a modified sympathetic ganglion.
Preganglionic fibers release ACh, causing chromaffin cells to secrete epinephrine and
norepinephrine into the blood.
Module 4 Exam Review – 82 Q&A (Portage
Learning, LockDown
**SECTION I: AUTONOMIC NERVOUS SYSTEM OVERVIEW AND COMPARISON
WITH SOMATIC NERVOUS SYSTEM (Questions 1-15)**
1. Define the autonomic nervous system and explain its primary function.
Answer: The ANS is the division of the peripheral nervous system that regulates
involuntary visceral functions including heart rate, blood pressure, digestion, and
glandular secretion to maintain homeostasis.
2. Compare the number of neurons in the efferent pathway between the somatic
nervous system and the ANS.
Answer: Somatic NS uses a single motor neuron from CNS to skeletal muscle. ANS
uses a two-neuron chain consisting of a preganglionic neuron and a postganglionic
neuron.
3. Differentiate between visceral sensory neurons and somatic sensory neurons.
Answer: Visceral sensory neurons monitor internal conditions such as stretch, chemical
changes, and temperature in organs. Somatic sensory neurons monitor external stimuli
and skeletal muscle proprioception.
4. Explain why the ANS is considered both afferent and efferent.
Answer: Visceral afferent fibers carry sensory information from organs to the CNS, while
visceral efferent fibers carry motor commands from the CNS to smooth muscle, cardiac
muscle, and glands.
, 5. Describe the two major divisions of the ANS and their anatomical origins.
Answer: Sympathetic division arises from thoracolumbar spinal cord (T1-L2).
Parasympathetic division arises from craniosacral regions (cranial nerves III, VII, IX, X
and S2-S4).
6. Define dual innervation and explain its functional significance.
Answer: Most visceral organs receive input from both sympathetic and parasympathetic
divisions. This allows fine-tuned antagonistic control of organ activity.
7. Identify organs that receive only sympathetic innervation.
Answer: Adrenal medulla, sweat glands, arrector pili muscles, most blood vessels, and
the kidney receive predominantly sympathetic innervation.
8. Explain the concept of autonomic tone.
Answer: The background level of ANS activity that maintains resting organ function.
Parasympathetic tone usually predominates in the heart and digestive tract at rest.
9. Compare the length of preganglionic fibers in the sympathetic versus
parasympathetic divisions.
Answer: Sympathetic preganglionic fibers are short. Parasympathetic preganglionic
fibers are long because ganglia are located near or within target organs.
10. Describe the location of sympathetic chain ganglia versus collateral ganglia.
Answer: Sympathetic chain (paravertebral) ganglia lie alongside the vertebral column.
Collateral (prevertebral) ganglia lie anterior to the vertebral column in the abdomen.
11. Explain the functional role of the adrenal medulla within the sympathetic nervous
system.
Answer: The adrenal medulla functions as a modified sympathetic ganglion.
Preganglionic fibers release ACh, causing chromaffin cells to secrete epinephrine and
norepinephrine into the blood.
