BIOL 251 Human Anatomy & Physiology
I w/Lab 2025 – Module 7 Exam Review
120Questions & Answers)
**1. What is the primary cell type responsible for generating and
transmitting electrical impulses in the nervous system?**
A. Astrocytes
B. Oligodendrocytes
C. Neurons
D. Ependymal cells
**Correct Answer: C. Neurons**
*Rationale:* Neurons are the excitable cells of the nervous system that
conduct action potentials. Glial cells (like astrocytes, oligodendrocytes,
and ependymal cells) provide support, protection, and nourishment .
**2. Which part of a neuron typically receives signals from other
neurons?**
A. Axon
B. Axon terminal
C. Dendrites
D. Myelin sheath
,**Correct Answer: C. Dendrites**
*Rationale:* Dendrites are highly branched projections that act as the
main receivers of incoming signals, conducting them toward the cell
body (soma) .
**3. The axon hillock is significant because it is the region where:**
A. Neurotransmitters are stored
B. The axon terminates at a synapse
C. Action potentials are initiated
D. Dendrites branch from the cell body
**Correct Answer: C. Action potentials are initiated**
*Rationale:* The axon hillock has a high density of voltage-gated
sodium channels and is the site where the action potential is generated
if the threshold is reached .
**4. Which type of glial cell is responsible for forming the myelin
sheath in the central nervous system (CNS)?**
A. Schwann cells
B. Satellite cells
C. Oligodendrocytes
D. Microglia
,**Correct Answer: C. Oligodendrocytes**
*Rationale:* Oligodendrocytes are the myelinating glia of the CNS. In
the peripheral nervous system (PNS), this function is performed by
Schwann cells .
**5. What is the primary function of astrocytes?**
A. To produce cerebrospinal fluid
B. To maintain the blood-brain barrier and support neurons
C. To phagocytize debris
D. To myelinate axons
**Correct Answer: B. To maintain the blood-brain barrier and support
neurons**
*Rationale:* Astrocytes are star-shaped glial cells that regulate the
chemical environment, support synaptic transmission, and help form
the blood-brain barrier .
**6. The resting membrane potential of a typical neuron is
approximately:**
A. +30 mV
B. 0 mV
C. -70 mV
D. -90 mV
, **Correct Answer: C. -70 mV**
*Rationale:* The resting membrane potential is negative inside relative
to the outside due to the distribution of ions and the activity of the
sodium-potassium pump .
**7. Which ion is primarily responsible for depolarizing a neuron during
an action potential?**
A. Potassium (K+)
B. Calcium (Ca2+)
C. Chloride (Cl-)
D. Sodium (Na+)
**Correct Answer: D. Sodium (Na+)**
*Rationale:* Depolarization occurs when voltage-gated sodium
channels open, allowing Na+ to rush into the cell, making the inside less
negative .
**8. What is the role of the sodium-potassium pump (Na+/K+ ATPase)
in maintaining resting membrane potential?**
A. It pumps 3 Na+ out and 2 K+ in, using ATP
B. It pumps 2 Na+ out and 3 K+ in, using ATP
C. It allows Na+ and K+ to leak down their gradients
D. It transports Na+ and K+ equally in both directions
I w/Lab 2025 – Module 7 Exam Review
120Questions & Answers)
**1. What is the primary cell type responsible for generating and
transmitting electrical impulses in the nervous system?**
A. Astrocytes
B. Oligodendrocytes
C. Neurons
D. Ependymal cells
**Correct Answer: C. Neurons**
*Rationale:* Neurons are the excitable cells of the nervous system that
conduct action potentials. Glial cells (like astrocytes, oligodendrocytes,
and ependymal cells) provide support, protection, and nourishment .
**2. Which part of a neuron typically receives signals from other
neurons?**
A. Axon
B. Axon terminal
C. Dendrites
D. Myelin sheath
,**Correct Answer: C. Dendrites**
*Rationale:* Dendrites are highly branched projections that act as the
main receivers of incoming signals, conducting them toward the cell
body (soma) .
**3. The axon hillock is significant because it is the region where:**
A. Neurotransmitters are stored
B. The axon terminates at a synapse
C. Action potentials are initiated
D. Dendrites branch from the cell body
**Correct Answer: C. Action potentials are initiated**
*Rationale:* The axon hillock has a high density of voltage-gated
sodium channels and is the site where the action potential is generated
if the threshold is reached .
**4. Which type of glial cell is responsible for forming the myelin
sheath in the central nervous system (CNS)?**
A. Schwann cells
B. Satellite cells
C. Oligodendrocytes
D. Microglia
,**Correct Answer: C. Oligodendrocytes**
*Rationale:* Oligodendrocytes are the myelinating glia of the CNS. In
the peripheral nervous system (PNS), this function is performed by
Schwann cells .
**5. What is the primary function of astrocytes?**
A. To produce cerebrospinal fluid
B. To maintain the blood-brain barrier and support neurons
C. To phagocytize debris
D. To myelinate axons
**Correct Answer: B. To maintain the blood-brain barrier and support
neurons**
*Rationale:* Astrocytes are star-shaped glial cells that regulate the
chemical environment, support synaptic transmission, and help form
the blood-brain barrier .
**6. The resting membrane potential of a typical neuron is
approximately:**
A. +30 mV
B. 0 mV
C. -70 mV
D. -90 mV
, **Correct Answer: C. -70 mV**
*Rationale:* The resting membrane potential is negative inside relative
to the outside due to the distribution of ions and the activity of the
sodium-potassium pump .
**7. Which ion is primarily responsible for depolarizing a neuron during
an action potential?**
A. Potassium (K+)
B. Calcium (Ca2+)
C. Chloride (Cl-)
D. Sodium (Na+)
**Correct Answer: D. Sodium (Na+)**
*Rationale:* Depolarization occurs when voltage-gated sodium
channels open, allowing Na+ to rush into the cell, making the inside less
negative .
**8. What is the role of the sodium-potassium pump (Na+/K+ ATPase)
in maintaining resting membrane potential?**
A. It pumps 3 Na+ out and 2 K+ in, using ATP
B. It pumps 2 Na+ out and 3 K+ in, using ATP
C. It allows Na+ and K+ to leak down their gradients
D. It transports Na+ and K+ equally in both directions
