Nervous System Study Questions: CNS & PNS
1. How much does the adult brain weigh? How many neurons does it possess? between 2.5 and
3.5 pounds; approximately 100 billion neurons
2. What are the four major anatomic regions of the brain? cerebrum, diencephalon, brain stem,
and cerebellum
3. The brain’s shape is not smooth. What are the names of the raised areas and the grooves
between them? Each of the curved, raised areas is called a gyrus, and each of the grooves
between the gyri is called a sulcus (shallow) or fissure (deep)
4. What divides the brain into right and left hemispheres? the longitudinal fissure
5. Which side of the brain controls movements on the right side of the body? the left brain
controls right-side body movements
6. Which side of the brain controls movements to the left side of the body? the right brain controls
left-side body movements
7. Where is Broca’s area found, and what is its function? the left frontal lobe; controls the tongue
and lip movements required for speech
8. What are the four main lobes of the cerebrum? the frontal, parietal, occipital, and temporal
lobes
9. Where is the primary somatic sensory cortex located, and what is its function? in the parietal
lobes; interprets sensory impulses received from the skin, internal organs, muscles, and joints
10. Why is the diencephalon, or interbrain, important? It houses the important structures of the
thalamus, hypothalamus, and epithalamus.
11. Describe the functions of the thalamus, hypothalamus, and eipthalamus. The thalamus relays
sensory and motor information between the body and the cerebral cortex. It also contributes to
regulating the body’s states of arousal, including sleep, wakefulness, and high-alert
consciousness. The hypothalamus regulates such autonomic nervous system functions as
metabolism, heart rate, blood pressure, thirst, hunger, energy level, and body temperature.
The centers for sex, pain, and pleasure also reside here. The epithalamus includes the pineal
gland and regulates and secretes sleep-cycle hormones.
12. What structures are in the brain stem and what are their functions? The midbrain serves as a
relay station for sensory and motor impulses. Specifi cally, it relays information concerning
vision, hearing, motor activity, sleep and wake cycles, arousal (alertness), and temperature
regulation. The pons, located immediately below the midbrain, plays a role in regulating
breathing. Inferior to the pons, the medulla oblongata regulates heart rate, blood pressure, and
breathing, and controls the reflexes for coughing, sneezing, and vomiting.
13. What is the role of the cerebellum? The cerebullum coordinates body movements, including
balance.
14. Describe the membranes that protect the brain and spinal cord? the meninges consists of three layers:
1. Dura Mater – outermost layer 2. Arachnoid Mater – located between the dura and pia
mater a. Subarachnoid space – lies between the arachnoid and pia mater and contains the
clear watery cerebrospinal fluid (CFS); 3. Pia Mater – very thin and contains nerves and
blood vessels that nourish underlying cells of the brain and spinal cord; hugs the surface of
these organs following their irregular contours, passing over high areas and dipping into
depressions
15. What are the primary functions of the reticular formation? regulates waking from slumber and
the heightened states of awareness
16. How many pairs of cranial nerves are found in the human body? 12 pairs of cranial nerves
17. Do the cranial nerves contain afferent (sensory) or efferent (fibers)? both afferent and efferent
fibers are found in various cranial nerves, while some cranial nerves (mixed nerves) contain
both types of fibers
Nervous System Study Questions: CNS & PNS
18. Which cranial nerves are responsible for eye movements? oculomotor, trochlear, and
abducens
19. What are mixed nerves? nerves that carry both afferent (sensory) and efferent (motor)
information
20. Which cranial nerves carry only afferent signals? olfactory, optic, and vestibulocochlear
21. How many pairs of spinal nerves are present in the body and how is each pair named? There
are 31 pairs of spinal nerves in the body, each named for the vertebral level from which it
originates.
22. What are the four plexuses of the body? cervical, brachial, lumbar, and sacral
23. Are spinal nerves efferent, afferent, or mixed? mixed
24. Which nervous system sends impulses to the heart—the somatic or the autonomic system?
25. List the two divisions of the autonomic nervous system. sympathetic and parasympathetic
26. Differentiate between the functions of the sympathetic and parasympathetic nervous systems.
The parasympathetic nervous system controls all of the automatic, day-in-and-day-out
functions of the circulatory, respiratory, and digestive systems. The sympathetic nervous
system activates the fight-or-flight response by stimulating organs of the endocrine system.
27. Explain the difference between a preganglionic neuron and a postganglionic neuron. A
preganglionic neuron is the first neuron in a series that connects the spinal cord with the
ganglion. A postganglionic neuron is the second neuron in a series that courses from the
ganglion to the cardiac muscle, smooth muscle, or a gland.
28. Be able to label the parts of the brain.
29. Be able to tell if the cranial nerves are sensory, motor, or mixed.