Cellular Biology | Portage Learning | Q & A |
2026 Edition
1. Which part of the neuron is primarily responsible for receiving signals from other neurons?
A) Axon
B) Dendrite
C) Soma
D) Myelin Sheath
Correct Answer: Dendrite
Rationale: Dendrites are tree-like extensions that branch out from the cell body. They increase the
surface area of the neuron and are the primary sites where signals are received from other neurons via
synapses. The axon transmits signals away from the soma.
2. What is the primary function of the myelin sheath?
A) To generate and conduct electrical impulses
B) To receive neurotransmitters from other neurons
C) To protect and insulate axons, increasing conduction speed
D) To regulate the concentration of ions inside the neuron
Correct Answer: To protect and insulate axons, increasing conduction speed
Rationale: The myelin sheath is a fatty, multilayered covering produced by glial cells. Its primary function
is to act as an electrical insulator, preventing ion leakage and increasing the speed at which action
potentials propagate down the axon via saltatory conduction.
3. Which structure is NOT part of the central nervous system (CNS)?
A) Brain
,B) Spinal cord
C) Ganglion
D) Medulla oblongata
Correct Answer: Ganglion
Rationale: The central nervous system (CNS) consists of the brain and spinal cord. A ganglion is a cluster
of nerve cell bodies located outside the CNS, making it a component of the peripheral nervous system
(PNS).
4. What is the primary role of the autonomic nervous system?
A) To control voluntary skeletal muscle movements
B) To process and interpret sensory information
C) To regulate involuntary bodily functions such as heart rate and digestion
D) To coordinate rapid reflex actions
Correct Answer: To regulate involuntary bodily functions such as heart rate and digestion
Rationale: The autonomic nervous system (ANS) is a control system that acts largely unconsciously. It
regulates involuntary physiological processes including heart rate, blood pressure, respiration, digestion,
and pupillary response.
5. The 'fight or flight' response is primarily activated by which division of the nervous system?
A) Somatic nervous system
B) Sympathetic nervous system
C) Parasympathetic nervous system
D) Enteric nervous system
Correct Answer: Sympathetic nervous system
, Rationale: The sympathetic nervous system is responsible for the body's rapid, involuntary response to
dangerous or stressful situations. It prepares the body for action by increasing heart rate, dilating pupils,
and diverting blood flow to muscles.
6. Which type of glial cell is responsible for forming the blood-brain barrier (BBB)?
A) Oligodendrocytes
B) Microglia
C) Astrocytes
D) Ependymal cells
Correct Answer: Astrocytes
Rationale: Astrocytes are star-shaped glial cells that have end-feet which wrap around blood vessels in
the brain. They are crucial for maintaining the integrity of the blood-brain barrier by regulating the
passage of substances from the blood into the brain tissue.
7. The production of cerebrospinal fluid (CSF) occurs in which structure?
A) Arachnoid villi
B) Choroid plexus
C) Pia mater
D) Dura mater
Correct Answer: Choroid plexus
Rationale: The choroid plexus is a network of specialized ependymal cells and blood vessels located
within the ventricles of the brain. It is responsible for the production of cerebrospinal fluid, which
cushions and nourishes the brain and spinal cord.
8. Neurotransmitters are typically released from which part of the neuron?
A) Dendrites
B) Cell body (soma)