BIOS 251 Exam 3 Essay Review | Chamberlain University 2026/2027
Exam 3 Essay: BIOS251 / BIOS 251 (Latest Update )
Anatomy and Physiology I with Lab
Review Questions with Verified Answers | 100% Correct | Grade A
Chamberlain University
50 Multiple-Choice Questions | 4 Sections | Nervous System, Sensory Physiology, Endocrine System, Integrated Clinical Scenarios
Section 1: Nervous System (CNS, PNS, Brain Regions, Spinal Cord, Cranial Nerves, Autonomic Nervous
System)
Q1: A 28-year-old patient presents with blurred vision, dilated pupils, dry mouth, and rapid heart rate after exposure to an
unknown chemical. Which division of the autonomic nervous system is most likely overstimulated?
A. Parasympathetic division (craniosacral outflow)
B. Sympathetic division (thoracolumbar outflow) [CORRECT]
C. Somatic motor division (voluntary skeletal muscle control)
D. Enteric nervous system (intrinsic plexuses of the GI tract)
Correct Answer: B
Rationale: The symptoms described - dilated pupils (mydriasis), dry mouth, tachycardia, and blurred vision from accommodation paralysis - are
hallmark signs of sympathetic (fight-or-flight) activation. The sympathetic division originates from the thoracolumbar region (T1-L2) of the spinal cord
and uses norepinephrine as the primary postganglionic neurotransmitter. Parasympathetic stimulation would produce the opposite effects: miosis,
salivation, bradycardia, and increased GI motility. The somatic motor division controls voluntary skeletal muscle and is not involved in these autonomic
symptoms. The enteric nervous system regulates GI function independently but does not control pupil size or heart rate.
Q2: A patient suffers a stroke that damages the left frontal lobe, specifically the precentral gyrus. Which clinical deficit
would the nurse practitioner most expect to find on assessment?
A. Loss of sensation in the right upper and lower extremities
B. Paralysis of voluntary movements on the right side of the body [CORRECT]
C. Difficulty comprehending spoken language (receptive aphasia)
D. Visual field deficits in the left half of the visual field
Correct Answer: B
Rationale: The precentral gyrus in the frontal lobe houses the primary motor cortex, which controls voluntary contralateral (opposite side) skeletal
muscle movements. Damage to the left precentral gyrus results in motor deficits on the right side of the body (hemiparesis or hemiplegia). Loss of
sensation would result from damage to the postcentral gyrus (primary somatosensory cortex) in the parietal lobe, not the precentral gyrus. Receptive
aphasia (Wernicke aphasia) results from damage to Wernicke area in the left temporal lobe, not the frontal motor cortex. Visual field deficits would
involve the occipital lobe (visual cortex), not the frontal motor area.
Q3: A nursing student is assessing cranial nerve function. When the patient is asked to stick out the tongue, it deviates to
the right side. Which cranial nerve is most likely affected?
A. Cranial nerve IX (glossopharyngeal)
B. Cranial nerve X (vagus)
C. Cranial nerve XI (accessory)
D. Cranial nerve XII (hypoglossal) [CORRECT]
Correct Answer: D
Rationale: The hypoglossal nerve (CN XII) is a pure motor nerve that controls tongue movements. Each genioglossus muscle (the major tongue
protruder) is innervated by the ipsilateral hypoglossal nerve. When CN XII is damaged on one side, the tongue deviates toward the weakened side
because the intact genioglossus on the healthy side pulls the tongue forward and toward the unaffected side, leaving the weak side to lag behind. CN IX
provides sensory and motor function to the pharynx and posterior tongue (taste), not tongue protrusion. CN X supplies autonomic and sensory functions
to thoracic and abdominal viscera and the pharynx. CN XI innervates the trapezius and sternocleidomastoid muscles, not the tongue.
Page 1
,BIOS 251 Exam 3 Essay Review | Chamberlain University 2026/2027
Q4: A patient with multiple sclerosis presents with impaired coordination, balance problems, and difficulty performing
rapid alternating movements. Which brain region is most likely affected by the demyelinating lesions in this patient?
A. Cerebrum (cerebral cortex)
B. Cerebellum [CORRECT]
C. Thalamus
D. Hypothalamus
Correct Answer: B
Rationale: The cerebellum, often called the little brain, is primarily responsible for coordination, balance, fine motor control, and motor learning. It
receives proprioceptive input from muscles, joints, and tendons and compares intended movement with actual movement to make real-time adjustments.
Damage to the cerebellum results in ataxia (uncoordinated movements), dysmetria (inability to judge distance and range), dysdiadochokinesia
(difficulty with rapid alternating movements), and balance disturbances. The cerebrum controls higher cognitive functions and voluntary motor
planning but not the fine coordination described. The thalamus serves as a sensory and motor relay station to the cortex but does not directly coordinate
movement. The hypothalamus regulates homeostasis (temperature, hunger, thirst, endocrine control) and is not involved in motor coordination.
Q5: During a patellar (knee-jerk) reflex examination, the physician notes an absent reflex response. This finding most
likely indicates damage to which of the following structures?
A. The sensory (afferent) pathway only
B. The motor (efferent) pathway only
C. Either the sensory or motor pathway, or the integration center in the spinal cord [CORRECT]
D. The higher brain centers that consciously control the reflex
Correct Answer: C
Rationale: The patellar reflex is a monosynaptic stretch reflex requiring only two neurons: a sensory (afferent) neuron and a motor (efferent) neuron,
with the synapse in the spinal cord (integration center). Areflexia can result from damage to any component of the reflex arc: the sensory neuron, the
motor neuron, or the spinal cord integration center. Higher brain centers are not required for this reflex since it occurs at the spinal cord level without
conscious input. While the brain can modulate reflexes (facilitate or inhibit), the basic reflex arc itself does not depend on brain involvement. Therefore,
damage to any single component could produce an absent reflex.
Q6: A 45-year-old patient is diagnosed with a tumor compressing the left oculomotor nerve (CN III). Which combination of
clinical signs would the clinician most likely observe on the left side?
A. Inability to abduct the eye and diplopia only
B. Ptosis (drooping eyelid), dilated pupil (mydriasis), and lateral deviation of the eye (exotropia) [CORRECT]
C. Loss of the corneal reflex and decreased lacrimation only
D. Inability to close the eye and loss of taste on the anterior two-thirds of the tongue
Correct Answer: B
Rationale: The oculomotor nerve (CN III) controls four extraocular muscles (superior, inferior, and medial recti, and inferior oblique), the levator
palpebrae superioris (eyelid elevation), and parasympathetic innervation to the sphincter pupillae (pupil constriction) and ciliary muscle
(accommodation). CN III damage causes: (1) ptosis from levator palpebrae weakness, (2) mydriasis from loss of parasympathetic constriction
(unopposed sympathetic action), and (3) exotropia (lateral eye deviation) because the lateral rectus (CN VI) is unopposed. Inability to abduct is CN VI
palsy. The corneal reflex involves CN V and CN VII. Inability to close the eye and loss of anterior tongue taste are CN VII (facial nerve) findings.
Page 2
, BIOS 251 Exam 3 Essay Review | Chamberlain University 2026/2027
Q7: Which of the following correctly describes the structural and functional organization of the meninges from outermost
to innermost?
A. Arachnoid mater, dura mater, pia mater
B. Dura mater, arachnoid mater, pia mater [CORRECT]
C. Pia mater, arachnoid mater, dura mater
D. Dura mater, pia mater, arachnoid mater
Correct Answer: B
Rationale: The three meningeal layers, from outermost to innermost, are: (1) Dura mater - the tough, thick, fibrous outermost layer that provides strong
protection and contains dural sinuses for venous drainage; (2) Arachnoid mater - the middle, web-like layer with the subarachnoid space beneath it
containing cerebrospinal fluid (CSF); and (3) Pia mater - the delicate, vascular innermost layer that tightly adheres to the surface of the brain and
spinal cord. This layered arrangement is critical for protecting the CNS and maintaining CSF circulation. The subarachnoid space between the
arachnoid and pia contains CSF that provides cushioning, nutrient exchange, and buoyancy.
Q8: A patient with a spinal cord injury at the T10 level presents with paralysis of both lower extremities but retains normal
motor and sensory function in the upper extremities and trunk above the umbilicus. This condition is best described as:
A. Quadriplegia (tetraplegia)
B. Paraplegia [CORRECT]
C. Hemiplegia
D. Brown-Sequard syndrome
Correct Answer: B
Rationale: Paraplegia is paralysis of the lower body (both lower extremities) resulting from spinal cord injury below the cervical region, typically at the
thoracic or lumbar level. T10 injury spares the upper extremities and trunk above the injury because the descending motor tracts and ascending sensory
tracts below T10 are disrupted, while those above remain intact. Quadriplegia results from cervical spinal cord injuries affecting all four limbs.
Hemiplegia (one-side paralysis) typically results from brain lesions such as stroke. Brown-Sequard syndrome results from hemisection of the spinal cord
and produces ipsilateral motor loss and contralateral pain/temperature loss below the lesion.
Q9: A clinical researcher is studying neurotransmitter receptors in the autonomic nervous system. A drug that selectively
activates nicotinic receptors would produce which of the following effects?
A. Excitatory responses at autonomic ganglia and at the neuromuscular junction of skeletal muscle [CORRECT]
B. Inhibitory responses in target organs innervated by the parasympathetic division
C. Decreased heart rate and increased glandular secretions in the digestive tract
D. Bronchodilation and vasodilation in skeletal muscle blood vessels
Correct Answer: A
Rationale: Nicotinic receptors are ligand-gated ion channels that are always excitatory when activated. They are located at two key sites: (1) all
autonomic ganglia (both sympathetic and parasympathetic), where they mediate fast synaptic transmission between pre- and postganglionic neurons,
and (2) the neuromuscular junction (NMJ) of skeletal muscle, where they mediate muscle contraction. A nicotinic agonist would therefore produce
excitation at ganglia and skeletal muscle. Inhibitory effects in parasympathetic target organs are mediated by muscarinic receptors. Decreased heart rate
and increased secretions are parasympathetic effects mediated by muscarinic receptors. Bronchodilation and vasodilation are sympathetic effects
mediated by adrenergic beta-2 receptors.
Page 3
Exam 3 Essay: BIOS251 / BIOS 251 (Latest Update )
Anatomy and Physiology I with Lab
Review Questions with Verified Answers | 100% Correct | Grade A
Chamberlain University
50 Multiple-Choice Questions | 4 Sections | Nervous System, Sensory Physiology, Endocrine System, Integrated Clinical Scenarios
Section 1: Nervous System (CNS, PNS, Brain Regions, Spinal Cord, Cranial Nerves, Autonomic Nervous
System)
Q1: A 28-year-old patient presents with blurred vision, dilated pupils, dry mouth, and rapid heart rate after exposure to an
unknown chemical. Which division of the autonomic nervous system is most likely overstimulated?
A. Parasympathetic division (craniosacral outflow)
B. Sympathetic division (thoracolumbar outflow) [CORRECT]
C. Somatic motor division (voluntary skeletal muscle control)
D. Enteric nervous system (intrinsic plexuses of the GI tract)
Correct Answer: B
Rationale: The symptoms described - dilated pupils (mydriasis), dry mouth, tachycardia, and blurred vision from accommodation paralysis - are
hallmark signs of sympathetic (fight-or-flight) activation. The sympathetic division originates from the thoracolumbar region (T1-L2) of the spinal cord
and uses norepinephrine as the primary postganglionic neurotransmitter. Parasympathetic stimulation would produce the opposite effects: miosis,
salivation, bradycardia, and increased GI motility. The somatic motor division controls voluntary skeletal muscle and is not involved in these autonomic
symptoms. The enteric nervous system regulates GI function independently but does not control pupil size or heart rate.
Q2: A patient suffers a stroke that damages the left frontal lobe, specifically the precentral gyrus. Which clinical deficit
would the nurse practitioner most expect to find on assessment?
A. Loss of sensation in the right upper and lower extremities
B. Paralysis of voluntary movements on the right side of the body [CORRECT]
C. Difficulty comprehending spoken language (receptive aphasia)
D. Visual field deficits in the left half of the visual field
Correct Answer: B
Rationale: The precentral gyrus in the frontal lobe houses the primary motor cortex, which controls voluntary contralateral (opposite side) skeletal
muscle movements. Damage to the left precentral gyrus results in motor deficits on the right side of the body (hemiparesis or hemiplegia). Loss of
sensation would result from damage to the postcentral gyrus (primary somatosensory cortex) in the parietal lobe, not the precentral gyrus. Receptive
aphasia (Wernicke aphasia) results from damage to Wernicke area in the left temporal lobe, not the frontal motor cortex. Visual field deficits would
involve the occipital lobe (visual cortex), not the frontal motor area.
Q3: A nursing student is assessing cranial nerve function. When the patient is asked to stick out the tongue, it deviates to
the right side. Which cranial nerve is most likely affected?
A. Cranial nerve IX (glossopharyngeal)
B. Cranial nerve X (vagus)
C. Cranial nerve XI (accessory)
D. Cranial nerve XII (hypoglossal) [CORRECT]
Correct Answer: D
Rationale: The hypoglossal nerve (CN XII) is a pure motor nerve that controls tongue movements. Each genioglossus muscle (the major tongue
protruder) is innervated by the ipsilateral hypoglossal nerve. When CN XII is damaged on one side, the tongue deviates toward the weakened side
because the intact genioglossus on the healthy side pulls the tongue forward and toward the unaffected side, leaving the weak side to lag behind. CN IX
provides sensory and motor function to the pharynx and posterior tongue (taste), not tongue protrusion. CN X supplies autonomic and sensory functions
to thoracic and abdominal viscera and the pharynx. CN XI innervates the trapezius and sternocleidomastoid muscles, not the tongue.
Page 1
,BIOS 251 Exam 3 Essay Review | Chamberlain University 2026/2027
Q4: A patient with multiple sclerosis presents with impaired coordination, balance problems, and difficulty performing
rapid alternating movements. Which brain region is most likely affected by the demyelinating lesions in this patient?
A. Cerebrum (cerebral cortex)
B. Cerebellum [CORRECT]
C. Thalamus
D. Hypothalamus
Correct Answer: B
Rationale: The cerebellum, often called the little brain, is primarily responsible for coordination, balance, fine motor control, and motor learning. It
receives proprioceptive input from muscles, joints, and tendons and compares intended movement with actual movement to make real-time adjustments.
Damage to the cerebellum results in ataxia (uncoordinated movements), dysmetria (inability to judge distance and range), dysdiadochokinesia
(difficulty with rapid alternating movements), and balance disturbances. The cerebrum controls higher cognitive functions and voluntary motor
planning but not the fine coordination described. The thalamus serves as a sensory and motor relay station to the cortex but does not directly coordinate
movement. The hypothalamus regulates homeostasis (temperature, hunger, thirst, endocrine control) and is not involved in motor coordination.
Q5: During a patellar (knee-jerk) reflex examination, the physician notes an absent reflex response. This finding most
likely indicates damage to which of the following structures?
A. The sensory (afferent) pathway only
B. The motor (efferent) pathway only
C. Either the sensory or motor pathway, or the integration center in the spinal cord [CORRECT]
D. The higher brain centers that consciously control the reflex
Correct Answer: C
Rationale: The patellar reflex is a monosynaptic stretch reflex requiring only two neurons: a sensory (afferent) neuron and a motor (efferent) neuron,
with the synapse in the spinal cord (integration center). Areflexia can result from damage to any component of the reflex arc: the sensory neuron, the
motor neuron, or the spinal cord integration center. Higher brain centers are not required for this reflex since it occurs at the spinal cord level without
conscious input. While the brain can modulate reflexes (facilitate or inhibit), the basic reflex arc itself does not depend on brain involvement. Therefore,
damage to any single component could produce an absent reflex.
Q6: A 45-year-old patient is diagnosed with a tumor compressing the left oculomotor nerve (CN III). Which combination of
clinical signs would the clinician most likely observe on the left side?
A. Inability to abduct the eye and diplopia only
B. Ptosis (drooping eyelid), dilated pupil (mydriasis), and lateral deviation of the eye (exotropia) [CORRECT]
C. Loss of the corneal reflex and decreased lacrimation only
D. Inability to close the eye and loss of taste on the anterior two-thirds of the tongue
Correct Answer: B
Rationale: The oculomotor nerve (CN III) controls four extraocular muscles (superior, inferior, and medial recti, and inferior oblique), the levator
palpebrae superioris (eyelid elevation), and parasympathetic innervation to the sphincter pupillae (pupil constriction) and ciliary muscle
(accommodation). CN III damage causes: (1) ptosis from levator palpebrae weakness, (2) mydriasis from loss of parasympathetic constriction
(unopposed sympathetic action), and (3) exotropia (lateral eye deviation) because the lateral rectus (CN VI) is unopposed. Inability to abduct is CN VI
palsy. The corneal reflex involves CN V and CN VII. Inability to close the eye and loss of anterior tongue taste are CN VII (facial nerve) findings.
Page 2
, BIOS 251 Exam 3 Essay Review | Chamberlain University 2026/2027
Q7: Which of the following correctly describes the structural and functional organization of the meninges from outermost
to innermost?
A. Arachnoid mater, dura mater, pia mater
B. Dura mater, arachnoid mater, pia mater [CORRECT]
C. Pia mater, arachnoid mater, dura mater
D. Dura mater, pia mater, arachnoid mater
Correct Answer: B
Rationale: The three meningeal layers, from outermost to innermost, are: (1) Dura mater - the tough, thick, fibrous outermost layer that provides strong
protection and contains dural sinuses for venous drainage; (2) Arachnoid mater - the middle, web-like layer with the subarachnoid space beneath it
containing cerebrospinal fluid (CSF); and (3) Pia mater - the delicate, vascular innermost layer that tightly adheres to the surface of the brain and
spinal cord. This layered arrangement is critical for protecting the CNS and maintaining CSF circulation. The subarachnoid space between the
arachnoid and pia contains CSF that provides cushioning, nutrient exchange, and buoyancy.
Q8: A patient with a spinal cord injury at the T10 level presents with paralysis of both lower extremities but retains normal
motor and sensory function in the upper extremities and trunk above the umbilicus. This condition is best described as:
A. Quadriplegia (tetraplegia)
B. Paraplegia [CORRECT]
C. Hemiplegia
D. Brown-Sequard syndrome
Correct Answer: B
Rationale: Paraplegia is paralysis of the lower body (both lower extremities) resulting from spinal cord injury below the cervical region, typically at the
thoracic or lumbar level. T10 injury spares the upper extremities and trunk above the injury because the descending motor tracts and ascending sensory
tracts below T10 are disrupted, while those above remain intact. Quadriplegia results from cervical spinal cord injuries affecting all four limbs.
Hemiplegia (one-side paralysis) typically results from brain lesions such as stroke. Brown-Sequard syndrome results from hemisection of the spinal cord
and produces ipsilateral motor loss and contralateral pain/temperature loss below the lesion.
Q9: A clinical researcher is studying neurotransmitter receptors in the autonomic nervous system. A drug that selectively
activates nicotinic receptors would produce which of the following effects?
A. Excitatory responses at autonomic ganglia and at the neuromuscular junction of skeletal muscle [CORRECT]
B. Inhibitory responses in target organs innervated by the parasympathetic division
C. Decreased heart rate and increased glandular secretions in the digestive tract
D. Bronchodilation and vasodilation in skeletal muscle blood vessels
Correct Answer: A
Rationale: Nicotinic receptors are ligand-gated ion channels that are always excitatory when activated. They are located at two key sites: (1) all
autonomic ganglia (both sympathetic and parasympathetic), where they mediate fast synaptic transmission between pre- and postganglionic neurons,
and (2) the neuromuscular junction (NMJ) of skeletal muscle, where they mediate muscle contraction. A nicotinic agonist would therefore produce
excitation at ganglia and skeletal muscle. Inhibitory effects in parasympathetic target organs are mediated by muscarinic receptors. Decreased heart rate
and increased secretions are parasympathetic effects mediated by muscarinic receptors. Bronchodilation and vasodilation are sympathetic effects
mediated by adrenergic beta-2 receptors.
Page 3
