NERVOUS SYSTEM: CNS, PNS, AND AUTONOMIC
FUNCTIONS |MEDSERG EXAM 2 | GUARANTEED
SUCCESS STARTS HERE! LEARN, PRACTICE &
EXCEL!
What are the two main components of the nervous system? Answer: The Central Nervous
System (CNS) and the Peripheral Nervous System (PNS).
What does the CNS consist of? Answer: The brain and spinal cord.
What are the primary functions of the brain? Answer: Sensation, responses, thought
processing, movement, communication, emotions, and memory.
How is the brain divided? Answer: Into two hemispheres (left and right) and approximately
nine areas including the cerebral cortex, hypothalamus, limbic system, and four lobes
(frontal, parietal, occipital, and temporal).
What protects the brain? Answer: The meninges, blood-brain barrier, and skull.
What are the two tracts of the spinal cord? Answer: The descending tract and the
ascending tract.
How many regions is the spinal cord divided into? Answer: Four regions: cervical, thoracic,
lumbar, and sacral.
What is the role of spinal nerves? Answer: They play a major role in communication within
the PNS.
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,What is the function of the PNS? Answer: To link and relay messages between the CNS and
the rest of the body.
What are the two divisions of the PNS? Answer: The somatic nervous system and the
autonomic nervous system (ANS).
What is the main difference between the somatic nervous system and the ANS? Answer:
Control: voluntary movements in the somatic nervous system versus involuntary control in
the ANS.
What is the role of the somatic nervous system? Answer: It is involved in voluntary
movements and reflex actions involving skeletal muscles.
What is a reflex arc? Answer: A neural pathway that controls a reflex action, involving
interneurons.
What happens during a deep tendon reflex assessment? Answer: A nurse taps on the
patellar tendon, eliciting a reflexive movement of the lower leg.
What indicates a potential issue with the somatic nervous system during a reflex
assessment? Answer: No response to the deep tendon reflex.
What does the ANS control? Answer: The body's internal environment in response to
stimuli, without conscious control.
What types of nerves are involved in the somatic nervous system? Answer: Afferent
(sensory) and efferent (motor) nerves.
What are sensory receptors? Answer: Structures that detect stimuli from the environment.
What are ganglia? Answer: Clusters of nerve cell bodies in the PNS.
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,What are motor endings? Answer: The terminals of motor neurons that communicate with
muscles.
What are interneurons? Answer: Neurons that connect sensory and motor pathways,
playing a key role in reflexes.
What is the function of afferent nerves? Answer: To carry sensory information to the CNS.
What is the function of efferent nerves? Answer: To carry motor commands from the CNS
to muscles.
How many pairs of spinal nerves are there? Answer: 31 pairs.
What is the primary function of the autonomic nervous system (ANS)? Answer: To control
involuntary physiological responses without conscious control.
What are the two main divisions of the ANS? Answer: The sympathetic nervous system
(SNS) and the parasympathetic nervous system (PSNS).
When is the sympathetic nervous system primarily active? Answer: During physical or
emotional stress, commonly referred to as the fight-or-flight response.
What is the role of the parasympathetic nervous system? Answer: To control the body
during non-stressful times, commonly referred to as the rest-and-digest response.
What types of physiological responses does the ANS regulate? Answer: Blood pressure,
heart rate, respiration, pupillary response, and sexual arousal.
How does the somatic nervous system differ from the ANS in terms of control? Answer:
The somatic nervous system is voluntary, while the ANS is involuntary.
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, What type of target organs does the ANS affect? Answer: Heart, lungs, eyes, smooth
muscle, and glands.
What is the communication pathway for the somatic nervous system? Answer: A single
nerve cell from the CNS directly to the skeletal muscle.
Describe the communication pathway of the ANS. Answer: A two-neuron chain: first
neuron from CNS to ganglia, second neuron from ganglia to target organs.
Where do pre-ganglionic neurons of the sympathetic nervous system originate? Answer:
From the thoracic and lumbar regions of the spinal cord (T1 to L2).
What neurotransmitter is released by pre-ganglionic neurons in the sympathetic nervous
system? Answer: Acetylcholine (ACh).
What neurotransmitters do post-ganglionic neurons in the sympathetic nervous system
release? Answer: Norepinephrine (NE) or epinephrine, depending on the area of the body.
What are the types of receptors on target organs in the sympathetic nervous system?
Answer: Adrenergic receptors, including alpha1, alpha2, beta1, and beta2.
What is the role of ganglia in the ANS? Answer: Ganglia are synapse points where pre-
ganglionic neurons connect with post-ganglionic neurons.
What is the term for the area where neurotransmission occurs between neurons in the
ANS? Answer: Synapse.
What is the difference in axon length between sympathetic and parasympathetic pre-
ganglionic neurons? Answer: Sympathetic pre-ganglionic neurons are shorter than
parasympathetic pre-ganglionic neurons.
APPHIA – Crafted with Care and Precision for Academic Excellence.
4
FUNCTIONS |MEDSERG EXAM 2 | GUARANTEED
SUCCESS STARTS HERE! LEARN, PRACTICE &
EXCEL!
What are the two main components of the nervous system? Answer: The Central Nervous
System (CNS) and the Peripheral Nervous System (PNS).
What does the CNS consist of? Answer: The brain and spinal cord.
What are the primary functions of the brain? Answer: Sensation, responses, thought
processing, movement, communication, emotions, and memory.
How is the brain divided? Answer: Into two hemispheres (left and right) and approximately
nine areas including the cerebral cortex, hypothalamus, limbic system, and four lobes
(frontal, parietal, occipital, and temporal).
What protects the brain? Answer: The meninges, blood-brain barrier, and skull.
What are the two tracts of the spinal cord? Answer: The descending tract and the
ascending tract.
How many regions is the spinal cord divided into? Answer: Four regions: cervical, thoracic,
lumbar, and sacral.
What is the role of spinal nerves? Answer: They play a major role in communication within
the PNS.
APPHIA – Crafted with Care and Precision for Academic Excellence.
1
,What is the function of the PNS? Answer: To link and relay messages between the CNS and
the rest of the body.
What are the two divisions of the PNS? Answer: The somatic nervous system and the
autonomic nervous system (ANS).
What is the main difference between the somatic nervous system and the ANS? Answer:
Control: voluntary movements in the somatic nervous system versus involuntary control in
the ANS.
What is the role of the somatic nervous system? Answer: It is involved in voluntary
movements and reflex actions involving skeletal muscles.
What is a reflex arc? Answer: A neural pathway that controls a reflex action, involving
interneurons.
What happens during a deep tendon reflex assessment? Answer: A nurse taps on the
patellar tendon, eliciting a reflexive movement of the lower leg.
What indicates a potential issue with the somatic nervous system during a reflex
assessment? Answer: No response to the deep tendon reflex.
What does the ANS control? Answer: The body's internal environment in response to
stimuli, without conscious control.
What types of nerves are involved in the somatic nervous system? Answer: Afferent
(sensory) and efferent (motor) nerves.
What are sensory receptors? Answer: Structures that detect stimuli from the environment.
What are ganglia? Answer: Clusters of nerve cell bodies in the PNS.
APPHIA – Crafted with Care and Precision for Academic Excellence.
2
,What are motor endings? Answer: The terminals of motor neurons that communicate with
muscles.
What are interneurons? Answer: Neurons that connect sensory and motor pathways,
playing a key role in reflexes.
What is the function of afferent nerves? Answer: To carry sensory information to the CNS.
What is the function of efferent nerves? Answer: To carry motor commands from the CNS
to muscles.
How many pairs of spinal nerves are there? Answer: 31 pairs.
What is the primary function of the autonomic nervous system (ANS)? Answer: To control
involuntary physiological responses without conscious control.
What are the two main divisions of the ANS? Answer: The sympathetic nervous system
(SNS) and the parasympathetic nervous system (PSNS).
When is the sympathetic nervous system primarily active? Answer: During physical or
emotional stress, commonly referred to as the fight-or-flight response.
What is the role of the parasympathetic nervous system? Answer: To control the body
during non-stressful times, commonly referred to as the rest-and-digest response.
What types of physiological responses does the ANS regulate? Answer: Blood pressure,
heart rate, respiration, pupillary response, and sexual arousal.
How does the somatic nervous system differ from the ANS in terms of control? Answer:
The somatic nervous system is voluntary, while the ANS is involuntary.
APPHIA – Crafted with Care and Precision for Academic Excellence.
3
, What type of target organs does the ANS affect? Answer: Heart, lungs, eyes, smooth
muscle, and glands.
What is the communication pathway for the somatic nervous system? Answer: A single
nerve cell from the CNS directly to the skeletal muscle.
Describe the communication pathway of the ANS. Answer: A two-neuron chain: first
neuron from CNS to ganglia, second neuron from ganglia to target organs.
Where do pre-ganglionic neurons of the sympathetic nervous system originate? Answer:
From the thoracic and lumbar regions of the spinal cord (T1 to L2).
What neurotransmitter is released by pre-ganglionic neurons in the sympathetic nervous
system? Answer: Acetylcholine (ACh).
What neurotransmitters do post-ganglionic neurons in the sympathetic nervous system
release? Answer: Norepinephrine (NE) or epinephrine, depending on the area of the body.
What are the types of receptors on target organs in the sympathetic nervous system?
Answer: Adrenergic receptors, including alpha1, alpha2, beta1, and beta2.
What is the role of ganglia in the ANS? Answer: Ganglia are synapse points where pre-
ganglionic neurons connect with post-ganglionic neurons.
What is the term for the area where neurotransmission occurs between neurons in the
ANS? Answer: Synapse.
What is the difference in axon length between sympathetic and parasympathetic pre-
ganglionic neurons? Answer: Sympathetic pre-ganglionic neurons are shorter than
parasympathetic pre-ganglionic neurons.
APPHIA – Crafted with Care and Precision for Academic Excellence.
4
