Portage Learning BIOL 251 Module 6 Human Anatomy & Physiology I with Lab 72 Original Practice Questions | 2026 Study Edition with Complete Answer Key & Rationales

Portage Learning BIOL 251 Module 6
Human Anatomy & Physiology I with Lab
72 Original Practice Questions | 2026 Study Edition
with Complete Answer Key & Rationales



Important Notice
This is an original, independently created study guide designed to help students review nervous-system concepts typically covered
in a Human Anatomy & Physiology I course. It is NOT an actual Portage Learning exam and does not reproduce, copy, or
paraphrase any proprietary Portage Learning questions, answer keys, or course materials. All questions, diagrams, and rationales
were written from scratch for exam-preparation purposes.

,SECTION 1 — QUESTIONS 1–72
Answer each question to the best of your ability. Multiple-choice and True/False items have one best answer;
matching items require you to pair each entry in Column 1 with its correct match in Column 2. Diagram-based
questions refer to the original schematic figure shown immediately above them.


Neuron Structure & Function




Diagram 1 — Original schematic of a multipolar neuron. Questions 1–2 refer to this diagram.

Question 1 (Neuron Structure & Function)
In the neuron diagram above, what structure is indicated by label A?
( ) A. Dendrite
( ) B. Axon
( ) C. Node of Ranvier
( ) D. Cell body (soma)

Question 2 (Neuron Structure & Function)
In the neuron diagram above, what structure is indicated by label G?
( ) A. Myelin sheath
( ) B. Node of Ranvier
( ) C. Axon hillock
( ) D. Synaptic knob

Question 3 (Neuron Structure & Function)
The primary function of dendrites is to:
( ) A. Generate and propagate action potentials down the axon

, ( ) B. Release neurotransmitter into the synaptic cleft
( ) C. Receive signals and conduct graded potentials toward the cell body
( ) D. Insulate the axon to speed conduction

Question 4 (Neuron Structure & Function)
Which part of the neuron has the lowest threshold for generating an action potential, due to its high density
of voltage-gated sodium channels?
( ) A. Dendrite
( ) B. Cell body
( ) C. Synaptic terminal
( ) D. Axon hillock

Question 5 (Neuron Structure & Function)
A neuron with a single axon and multiple dendrites extending from the cell body is classified structurally as:
( ) A. Multipolar
( ) B. Unipolar
( ) C. Bipolar
( ) D. Anaxonic

Question 6 (Neuron Structure & Function)
Functionally, a neuron that carries impulses from sensory receptors toward the CNS is classified as:
( ) A. Motor (efferent) neuron
( ) B. Sensory (afferent) neuron
( ) C. Interneuron
( ) D. Somatic motor neuron

Question 7 (Neuron Structure & Function)
A researcher compares two axons: one is large in diameter and heavily myelinated, the other is thin and
unmyelinated. Compared to the thin axon, the large myelinated axon will:
( ) A. Conduct impulses more slowly
( ) B. Be incapable of generating an action potential
( ) C. Conduct impulses more rapidly via saltatory conduction
( ) D. Have no resting membrane potential

Question 8 (Neuron Structure & Function)
True or False: Unlike most body cells, mature neurons are generally amitotic and have a very limited
capacity to divide.
( ) A. True
( ) B. False


Neuroglia

Question 9 (Neuroglia)
Which neuroglial cell forms the myelin sheath around axons in the CNS?

, ( ) A. Schwann cell
( ) B. Astrocyte
( ) C. Microglia
( ) D. Oligodendrocyte

Question 10 (Neuroglia)
Which neuroglial cell is responsible for myelinating axons in the PNS?
( ) A. Schwann cell
( ) B. Oligodendrocyte
( ) C. Ependymal cell
( ) D. Astrocyte

Question 11 (Neuroglia)
Which glial cell helps form the blood–brain barrier and provides structural and metabolic support to CNS
neurons?
( ) A. Microglia
( ) B. Astrocyte
( ) C. Oligodendrocyte
( ) D. Satellite cell

Question 12 (Neuroglia)
Which neuroglial cells act as phagocytes, removing debris and pathogens within the CNS?
( ) A. Ependymal cells
( ) B. Astrocytes
( ) C. Microglia
( ) D. Oligodendrocytes

Question 13 (Neuroglia)
Match each neuroglial cell (1–4) with its correct location or function (A–D).
Column 1 Column 2
1. Ependymal cell A. Lines the ventricles and central canal; helps
circulate CSF
2. Satellite cell B. Surrounds neuron cell bodies within PNS ganglia
3. Astrocyte C. Contributes to the blood–brain barrier and metabolic
support in the CNS
4. Schwann cell D. Myelinates a single axon segment in the PNS



Synaptic Transmission

Question 14 (Synaptic Transmission)
At a chemical synapse, an arriving action potential opens voltage-gated channels for which ion, triggering
neurotransmitter release?
( ) A. Sodium
( ) B. Potassium