A&P 1 101 Module 6 Lab Exam
Portage Learning | 2026/2027 Edition
Neuromuscular Histology, Gross Brain Anatomy &
Sarcomere Microscopy
DOMAIN 1: Histology of Nervous and Muscular Tissue (8 Questions)
Question 1 — Multiple-Choice (Image-Based)
You are examining a microscope slide of nervous tissue. The cell body you observe is large, star-
shaped, and contains granular dark-staining structures throughout the cytoplasm. The nucleus is
large, round, and centrally located with a prominent nucleolus. Based on these histological
features, this cell is best identified as:
A) A pseudounipolar sensory neuron from the dorsal root ganglion
B) A Purkinje cell from the cerebellar cortex
C) A multipolar motor neuron with Nissl bodies in the perikaryon [CORRECT]
D) An astrocyte with glial fibrillary acidic protein (GFAP) filaments
Rationale: The large, star-shaped cell body with granular dark-staining cytoplasm (Nissl bodies)
and a large central nucleus with a prominent nucleolus are the definitive histological
characteristics of a multipolar motor neuron. The Nissl bodies represent rough endoplasmic
reticulum (RER) actively synthesizing proteins for the neuron. The granular dark staining is the
key visual cue distinguishing motor neuron perikarya from other neural cell types.
Question 2 — Multiple-Choice (Image-Based)
A student is viewing a spinal cord smear under high magnification. They identify a large cell with
an eccentric nucleus and granular cytoplasmic inclusions. The instructor asks them to point to
the Nissl bodies. The student should indicate:
A) The clear, unstained region surrounding the nucleus
B) The granular, basophilic (dark purple-blue) clusters of rough endoplasmic reticulum in the
cytoplasm [CORRECT]
,C) The elongated axon hillock extending from the cell body
D) The lipofuscin pigment granules adjacent to the nucleus
Rationale: Nissl bodies are specifically identified as granular, basophilic (dark purple-blue when
stained with basic dyes such as cresyl violet or toluidine blue) clusters of rough endoplasmic
reticulum (RER) and free ribosomes within the perikaryon (cell body) of a multipolar motor
neuron. The granular dark staining is the critical visual cue for identification on a histology slide.
Question 3 — True/False
When examining a multipolar motor neuron under the microscope, the Nissl bodies are
composed of smooth endoplasmic reticulum (SER) and are responsible for lipid synthesis and
detoxification.
A) True
B) False [CORRECT]
Rationale: This statement is false. Nissl bodies are specifically composed of rough endoplasmic
reticulum (RER), not smooth endoplasmic reticulum (SER). The RER contains ribosomes on its
surface, giving the granular dark-staining appearance observed under the microscope. Nissl
bodies are responsible for protein synthesis (not lipid synthesis or detoxification), which is
essential for maintaining the large metabolic demands of the motor neuron and producing
neurotransmitters and structural proteins for the axon.
Question 4 — Multiple-Choice (Image-Based)
A histology slide shows branching, striated muscle fibers with faint cross-bands connecting
individual cells. Each cell contains a single, centrally located nucleus. A student incorrectly
identifies this as skeletal muscle. What specific histological feature should the student have
used to correctly identify this tissue as cardiac muscle?
A) The presence of multiple peripheral nuclei per fiber
B) The presence of intercalated discs and a single central nucleus per cell [CORRECT]
C) The absence of striations and the presence of gap junctions
D) The presence of T-tubules at the A-I band junction
Rationale: Cardiac muscle is correctly identified by three key histological features visible on a
microscope slide: (1) striations (similar to skeletal muscle), (2) a single, centrally located nucleus
per cardiomyocyte, and (3) intercalated discs—the dark-staining step-like lines that connect
adjacent cardiac muscle cells end-to-end. Skeletal muscle, by contrast, has multiple peripheral
, nuclei per fiber and lacks intercalated discs. The intercalated discs contain desmosomes and gap
junctions, which facilitate the coordinated, autorhythmic contractions of the heart.
Question 5 — True/False
Cardiac muscle tissue is described as autorhythmic because the intercalated discs contain gap
junctions that allow electrical impulses to spread rapidly from cell to cell, enabling the heart to
contract as a functional syncytium without requiring external nervous stimulation for each
heartbeat.
A) True [CORRECT]
B) False
Rationale: This statement is true. The intercalated discs of cardiac muscle contain gap junctions
that permit the rapid passage of ions (and thus action potentials) between adjacent
cardiomyocytes. This property, combined with the intrinsic pacemaker activity of the sinoatrial
(SA) node, gives cardiac muscle its autorhythmicity—the ability to generate its own rhythmic
contractions. The heart can continue beating even when isolated from the central nervous
system, though autonomic innervation modulates the rate.
Question 6 — Matching
Match each glial cell type with its primary function and identifying histological characteristic.
Each answer may be used once, more than once, or not at all.
Table
Glial Cell Type Function & Characteristic
1. Astrocyte
2. Oligodendrocyte
3. Microglia
4. Ependymal cell
Portage Learning | 2026/2027 Edition
Neuromuscular Histology, Gross Brain Anatomy &
Sarcomere Microscopy
DOMAIN 1: Histology of Nervous and Muscular Tissue (8 Questions)
Question 1 — Multiple-Choice (Image-Based)
You are examining a microscope slide of nervous tissue. The cell body you observe is large, star-
shaped, and contains granular dark-staining structures throughout the cytoplasm. The nucleus is
large, round, and centrally located with a prominent nucleolus. Based on these histological
features, this cell is best identified as:
A) A pseudounipolar sensory neuron from the dorsal root ganglion
B) A Purkinje cell from the cerebellar cortex
C) A multipolar motor neuron with Nissl bodies in the perikaryon [CORRECT]
D) An astrocyte with glial fibrillary acidic protein (GFAP) filaments
Rationale: The large, star-shaped cell body with granular dark-staining cytoplasm (Nissl bodies)
and a large central nucleus with a prominent nucleolus are the definitive histological
characteristics of a multipolar motor neuron. The Nissl bodies represent rough endoplasmic
reticulum (RER) actively synthesizing proteins for the neuron. The granular dark staining is the
key visual cue distinguishing motor neuron perikarya from other neural cell types.
Question 2 — Multiple-Choice (Image-Based)
A student is viewing a spinal cord smear under high magnification. They identify a large cell with
an eccentric nucleus and granular cytoplasmic inclusions. The instructor asks them to point to
the Nissl bodies. The student should indicate:
A) The clear, unstained region surrounding the nucleus
B) The granular, basophilic (dark purple-blue) clusters of rough endoplasmic reticulum in the
cytoplasm [CORRECT]
,C) The elongated axon hillock extending from the cell body
D) The lipofuscin pigment granules adjacent to the nucleus
Rationale: Nissl bodies are specifically identified as granular, basophilic (dark purple-blue when
stained with basic dyes such as cresyl violet or toluidine blue) clusters of rough endoplasmic
reticulum (RER) and free ribosomes within the perikaryon (cell body) of a multipolar motor
neuron. The granular dark staining is the critical visual cue for identification on a histology slide.
Question 3 — True/False
When examining a multipolar motor neuron under the microscope, the Nissl bodies are
composed of smooth endoplasmic reticulum (SER) and are responsible for lipid synthesis and
detoxification.
A) True
B) False [CORRECT]
Rationale: This statement is false. Nissl bodies are specifically composed of rough endoplasmic
reticulum (RER), not smooth endoplasmic reticulum (SER). The RER contains ribosomes on its
surface, giving the granular dark-staining appearance observed under the microscope. Nissl
bodies are responsible for protein synthesis (not lipid synthesis or detoxification), which is
essential for maintaining the large metabolic demands of the motor neuron and producing
neurotransmitters and structural proteins for the axon.
Question 4 — Multiple-Choice (Image-Based)
A histology slide shows branching, striated muscle fibers with faint cross-bands connecting
individual cells. Each cell contains a single, centrally located nucleus. A student incorrectly
identifies this as skeletal muscle. What specific histological feature should the student have
used to correctly identify this tissue as cardiac muscle?
A) The presence of multiple peripheral nuclei per fiber
B) The presence of intercalated discs and a single central nucleus per cell [CORRECT]
C) The absence of striations and the presence of gap junctions
D) The presence of T-tubules at the A-I band junction
Rationale: Cardiac muscle is correctly identified by three key histological features visible on a
microscope slide: (1) striations (similar to skeletal muscle), (2) a single, centrally located nucleus
per cardiomyocyte, and (3) intercalated discs—the dark-staining step-like lines that connect
adjacent cardiac muscle cells end-to-end. Skeletal muscle, by contrast, has multiple peripheral
, nuclei per fiber and lacks intercalated discs. The intercalated discs contain desmosomes and gap
junctions, which facilitate the coordinated, autorhythmic contractions of the heart.
Question 5 — True/False
Cardiac muscle tissue is described as autorhythmic because the intercalated discs contain gap
junctions that allow electrical impulses to spread rapidly from cell to cell, enabling the heart to
contract as a functional syncytium without requiring external nervous stimulation for each
heartbeat.
A) True [CORRECT]
B) False
Rationale: This statement is true. The intercalated discs of cardiac muscle contain gap junctions
that permit the rapid passage of ions (and thus action potentials) between adjacent
cardiomyocytes. This property, combined with the intrinsic pacemaker activity of the sinoatrial
(SA) node, gives cardiac muscle its autorhythmicity—the ability to generate its own rhythmic
contractions. The heart can continue beating even when isolated from the central nervous
system, though autonomic innervation modulates the rate.
Question 6 — Matching
Match each glial cell type with its primary function and identifying histological characteristic.
Each answer may be used once, more than once, or not at all.
Table
Glial Cell Type Function & Characteristic
1. Astrocyte
2. Oligodendrocyte
3. Microglia
4. Ependymal cell
