,BIO 201 Exam 4 – Anatomy & Physiology I
(2026) Q&A | StraighterLine
1. The ability of the nervous system to detect changes in the internal or external
environment is called:
A) Sensory input
B) Motor output
C) Integration
D) Homeostasis
Correct Answer: Sensory input
Rationale: Sensory input involves receptors that monitor stimuli and transmit
signals to the CNS. Integration is the processing of that information, and motor
output is the response. Homeostasis is the overall balance maintained by these
functions.
2. The brain and spinal cord together form the:
A) Peripheral nervous system
B) Central nervous system
C) Autonomic nervous system
D) Somatic nervous system
Correct Answer: Central nervous system
,Rationale: The CNS is the integrating and command center. The PNS consists of
nerves and ganglia outside the CNS. The autonomic and somatic systems are
subdivisions of the PNS.
3. A bundle of axons in the peripheral nervous system is called a:
A) Ganglion
B) Nucleus
C) Nerve
D) Tract
Correct Answer: Nerve
Rationale: Nerves are bundles of axons in the PNS. Tracts are axon bundles in
the CNS. Ganglia are clusters of neuronal cell bodies in the PNS; nuclei are
clusters in the CNS.
4. The myelin sheath in the peripheral nervous system is produced by:
A) Oligodendrocytes
B) Astrocytes
C) Microglia
D) Schwann cells
Correct Answer: Schwann cells
, Rationale: Schwann cells wrap around peripheral axons, forming the insulating
myelin. Oligodendrocytes perform this function in the CNS. Astrocytes help form
the blood‑brain barrier; microglia are immune cells.
5. Gaps in the myelin sheath where action potentials are regenerated are called:
A) Nodes of Ranvier
B) Synaptic clefts
C) Dendrites
D) Axon hillocks
Correct Answer: Nodes of Ranvier
Rationale: The nodes of Ranvier are periodic gaps where voltage‑gated ion
channels are concentrated, allowing saltatory conduction. The synaptic cleft is
between neurons; dendrites receive signals; the axon hillock is the trigger zone.
6. The part of a neuron that receives incoming signals from other neurons is the:
A) Axon
B) Dendrite
C) Soma
D) Axon terminal
Correct Answer: Dendrite
(2026) Q&A | StraighterLine
1. The ability of the nervous system to detect changes in the internal or external
environment is called:
A) Sensory input
B) Motor output
C) Integration
D) Homeostasis
Correct Answer: Sensory input
Rationale: Sensory input involves receptors that monitor stimuli and transmit
signals to the CNS. Integration is the processing of that information, and motor
output is the response. Homeostasis is the overall balance maintained by these
functions.
2. The brain and spinal cord together form the:
A) Peripheral nervous system
B) Central nervous system
C) Autonomic nervous system
D) Somatic nervous system
Correct Answer: Central nervous system
,Rationale: The CNS is the integrating and command center. The PNS consists of
nerves and ganglia outside the CNS. The autonomic and somatic systems are
subdivisions of the PNS.
3. A bundle of axons in the peripheral nervous system is called a:
A) Ganglion
B) Nucleus
C) Nerve
D) Tract
Correct Answer: Nerve
Rationale: Nerves are bundles of axons in the PNS. Tracts are axon bundles in
the CNS. Ganglia are clusters of neuronal cell bodies in the PNS; nuclei are
clusters in the CNS.
4. The myelin sheath in the peripheral nervous system is produced by:
A) Oligodendrocytes
B) Astrocytes
C) Microglia
D) Schwann cells
Correct Answer: Schwann cells
, Rationale: Schwann cells wrap around peripheral axons, forming the insulating
myelin. Oligodendrocytes perform this function in the CNS. Astrocytes help form
the blood‑brain barrier; microglia are immune cells.
5. Gaps in the myelin sheath where action potentials are regenerated are called:
A) Nodes of Ranvier
B) Synaptic clefts
C) Dendrites
D) Axon hillocks
Correct Answer: Nodes of Ranvier
Rationale: The nodes of Ranvier are periodic gaps where voltage‑gated ion
channels are concentrated, allowing saltatory conduction. The synaptic cleft is
between neurons; dendrites receive signals; the axon hillock is the trigger zone.
6. The part of a neuron that receives incoming signals from other neurons is the:
A) Axon
B) Dendrite
C) Soma
D) Axon terminal
Correct Answer: Dendrite
