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Chamberlain University-Illinois
BIOS 252
BIOS252 EXAM 2 STUDY SET Questions
and Answers 2026 Latest Update
How many pairs of spinal nerves are there? Ans: 31 pairs
how many cervical nerves are there? Ans: 8 pairs
how many thoracic nerves are there? Ans: 12 pairs
how many pairs of lumbar nerves are there? Ans: 5 pairs
how many pairs of sacral nerves are there? Ans: 5 pairs
how many pairs of coccygeal nerves are there? Ans: 1 pair
What is the dorsal root? Ans: axons of sensory neurons
what is the ventral root? Ans: axons of motor neurons ( efferent)
Do spinal nerves contain both sensory and motor neurons? Ans: yes
What is a myotome? Ans: specific muscle groups innervated by specific
levels of spinal nerves
what is a dermatome? Ans: specific patches of skin innervated by specific
levels of the spinal column
what is a endoneurium? Ans: connective tissue surrounding each individual
axon
What is the perineurium? Ans: connective tissue that surrounds a bundle of
axons making a nerve fascicle
What is the epineurium? Ans: surrounds the entire nerve
What is the cervical plexus? Ans: C1-C5
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what is notable nerves? Ans: Phrenic Nerve (C3-C5)
brachial plexus Ans: C5-T1, nerves to upper limb, neck, and shoulder
muscles
lumbar plexus Ans: L1-L4, nerves to abdominal wall, genitals, and lower
limb
sacral and coccygeal plexus Ans: l5-s1, nerves to the buttock, perineum, and
lower limb notable nerves; sciatic nerve, tibial and common fibular
what is a reflex? Ans: fast, involuntary and predictable sequence of events
that function as an arc
what are the 5 steps to a reflex? Ans: Sensory receptor, sensory neuron,
interneuron, motor neuron, effector
Ipsilateral Ans: same side
contralateral Ans: opposite side
monosynaptic Ans: one synapse
polysynaptic Ans: multiple neurons stimulated
Sensory tracts Ans: usually begins with SPINO - afferent pathways
spinothalamic tract Ans: (antero and lateral) takes pain, temp, itch, and
tickle to the thalamus; decussates in the cord upon level of entry
Posterior columns Ans: (Cuneate and Gracile) takes touch, pressure, and
vibration to the thalamus; decussates in the medulla
Motor tracts Ans: tracts consisting of axons that carry nerve impulses from
the brain
corticospinal tract Ans: connections between brain and spine
ANS Ans: autonomic nervous system
autonomic vs somatic Ans: autonomic (involuntary) and somatic (voluntary)
Sympathetics - Lateral Grey horns of thoracic lumbar spine, sympathetic
trunk and preverterebral ganglia, short pre-ganglionic nerve; long post
© 2026 All rights reserved
Chamberlain University-Illinois
BIOS 252
BIOS252 EXAM 2 STUDY SET Questions
and Answers 2026 Latest Update
How many pairs of spinal nerves are there? Ans: 31 pairs
how many cervical nerves are there? Ans: 8 pairs
how many thoracic nerves are there? Ans: 12 pairs
how many pairs of lumbar nerves are there? Ans: 5 pairs
how many pairs of sacral nerves are there? Ans: 5 pairs
how many pairs of coccygeal nerves are there? Ans: 1 pair
What is the dorsal root? Ans: axons of sensory neurons
what is the ventral root? Ans: axons of motor neurons ( efferent)
Do spinal nerves contain both sensory and motor neurons? Ans: yes
What is a myotome? Ans: specific muscle groups innervated by specific
levels of spinal nerves
what is a dermatome? Ans: specific patches of skin innervated by specific
levels of the spinal column
what is a endoneurium? Ans: connective tissue surrounding each individual
axon
What is the perineurium? Ans: connective tissue that surrounds a bundle of
axons making a nerve fascicle
What is the epineurium? Ans: surrounds the entire nerve
What is the cervical plexus? Ans: C1-C5
© 2026 All rights reserved
, 2 | Page
what is notable nerves? Ans: Phrenic Nerve (C3-C5)
brachial plexus Ans: C5-T1, nerves to upper limb, neck, and shoulder
muscles
lumbar plexus Ans: L1-L4, nerves to abdominal wall, genitals, and lower
limb
sacral and coccygeal plexus Ans: l5-s1, nerves to the buttock, perineum, and
lower limb notable nerves; sciatic nerve, tibial and common fibular
what is a reflex? Ans: fast, involuntary and predictable sequence of events
that function as an arc
what are the 5 steps to a reflex? Ans: Sensory receptor, sensory neuron,
interneuron, motor neuron, effector
Ipsilateral Ans: same side
contralateral Ans: opposite side
monosynaptic Ans: one synapse
polysynaptic Ans: multiple neurons stimulated
Sensory tracts Ans: usually begins with SPINO - afferent pathways
spinothalamic tract Ans: (antero and lateral) takes pain, temp, itch, and
tickle to the thalamus; decussates in the cord upon level of entry
Posterior columns Ans: (Cuneate and Gracile) takes touch, pressure, and
vibration to the thalamus; decussates in the medulla
Motor tracts Ans: tracts consisting of axons that carry nerve impulses from
the brain
corticospinal tract Ans: connections between brain and spine
ANS Ans: autonomic nervous system
autonomic vs somatic Ans: autonomic (involuntary) and somatic (voluntary)
Sympathetics - Lateral Grey horns of thoracic lumbar spine, sympathetic
trunk and preverterebral ganglia, short pre-ganglionic nerve; long post
© 2026 All rights reserved
