- Where are oligodendrocytes located?
- Peripheral nervous system
- Dorsal root ganglia
- Central nervous system
- Peripheral nerves
Oligodendrocytes are the myelinating glia of the central nervous system (brain and spinal cord). Each oligodendrocyte myelinates multiple axons.
Dorsal root ganglia and peripheral nerves are in the PNS.
- Where are Schwann cells located?
- Peripheral nervous system
- Central nervous system
- Cerebral cortex
- Spinal cord
Schwann cells myelinate axons in the peripheral nervous system. One Schwann cell myelinates a single axonal segment.
The cerebral cortex and spinal cord are CNS structures (oligodendrocytes provide myelin there).
- Which of the following types of cells is the most common in the CNS?
- Astrocytes
- Oligocytes
- Neurocytes
- Celiac cells
Astrocytes are the most abundant glial cells in the CNS. They provide structural support, help maintain the blood–brain barrier via end-feet on capillaries, regulate extracellular K+ and neurotransmitter levels, and contribute to repair/glial scar formation.
- Which of the following is a regulatory protein in the cytoplasm that helps the processes at the synapse?
- Calmodulin
- Protein kinase
- Ligand
- Gap protein
Calmodulin is a cytosolic Ca2+-binding regulatory protein that activates enzymes critical for synaptic vesicle cycling and plasticity.
Protein kinase is a broad class, ligand is any receptor-binding molecule, and “gap protein” is not a standard synaptic term.
- Myasthenia gravis is due to which kind of receptors being blocked and destroyed by antibodies?
- Epinephrine
- Nicotinic
- GABA
- Transient
In myasthenia gravis, autoantibodies target the nicotinic acetylcholine receptor at the neuromuscular junction, reducing ACh signaling and causing fatigable weakness.
- The primary effect of cocaine on the nervous system is that cocaine blocks the reuptake of…
- Monoamines
- Transaminases
- Acetylcholine
- Monoamine oxidase
Cocaine blocks the reuptake transporters for monoamines, increasing synaptic levels.
Transaminases and monoamine oxidase are enzymes, not reuptake transporters.
- Which of the following amino acids can function as a neurotransmitter in the CNS?
- Leucine
- Glutamic acid
- Lysine
- Valine
Leucine, lysine, and valine are proteinogenic amino acids, not classical CNS neurotransmitters.
- Huntington’s disease has been linked with a deficiency in which neurotransmitter?
- Lysine
- GABA
- Valine
- Tyrosine
Huntington’s disease features degeneration of striatal neurons with decreased GABA (and ACh) output from the basal ganglia circuitry.
- Which of the following is NOT considered a monoamine?
- Epinephrine
- Norepinephrine
- Dopamine
- Adenosine
Epinephrine, norepinephrine, and dopamine are monoamines. Adenosine is a purine nucleoside, not a monoamine.
- Which of the following is not considered a catecholamine?
- Dopamine
- Norepinephrine
- Serotonin
- Epinephrine
Catecholamines share a catechol ring derived from tyrosine. Serotonin is an indolamine, not a catecholamine.
- Hyperpolarization due to GABA is caused by opening of which channels?
- Ca++
- Cl–
- K+
- Na+
GABAA receptor activation opens Cl– channels, allowing chloride influx and causing membrane hyperpolarization.
GABAB additionally increases K+ efflux via GPCRs, but the classic fast effect is Cl– influx.
- What does valium have an effect on to inhibit neural transmission?
- Epinephrine
- Norepinephrine
- GABA
- Dopamine
Valium (diazepam) is a benzodiazepine that positively modulates GABAA receptors, increasing the frequency of Cl– channel opening and inhibiting neuronal firing.
- Which drug blocks the reuptake of serotonin into presynaptic axons?
- Prozac
- Valium
- Xanax
- Deprenyl
Prozac is a selective serotonin reuptake inhibitor (SSRI) that blocks SERT on presynaptic terminals.
Valium and Xanax are benzodiazepines, while deprenyl is an MAO-B inhibitor.
- Which of the following toxins blocks sodium channels?
- Strychnine
- Neostigmine
- Tetrodotoxin
- Curare
Tetrodotoxin blocks voltage-gated Na+ channels, preventing action potential initiation and propagation.
Strychnine blocks glycine receptors, neostigmine inhibits acetylcholinesterase, and curare blocks nicotinic ACh receptors.
- Clostridium botulinum releases which enzyme that destroys peptide bonds?
- Amylase
- Endopeptidase
- Exopeptidase
- Protein kinase
Botulinum neurotoxins are zinc-dependent endopeptidases that cleave SNARE proteins, blocking ACh release at the NMJ.
- Multiple sclerosis is a disease that attacks which part of neurons in the CNS?
- Myelin sheaths
- Axon terminals
- Sodium channels
- Nicotinic receptors
Multiple sclerosis is an autoimmune demyelinating disease of the CNS that targets myelin sheaths produced by oligodendrocytes, slowing conduction.
- Which of the following is NOT considered a type of synapse?
- Dendrodendritic
- Axosomatic
- Axoaxonic
- Denoaxonic
Recognized synapse types include axosomatic, axoaxonic, and dendrodendritic. “Denoaxonic” is not a standard synaptic classification.
- What is the progression of a nerve impulse with the nodes of Ranvier called?
- Saltatory conduction
- Transmission
- Unmyelinated conduction
- Relative conduction
Action potentials “leap” from one node of Ranvier to the next during saltatory conduction, greatly increasing conduction velocity in myelinated axons.
- What are supporting cells located within the CNS collectively called?
- Neuroglia
- Astrocytes
- Perikaryon
- Satellite cells
Supporting cells in the CNS are the neuroglia. Perikaryon refers to the neuron cell body, and satellite cells are PNS glia.
- Which of the following types of cells line the ventricles and spinal cord?
- Astrocytes
- Schwann cells
- Ependymal cells
- Oligodendrocytes
Ependymal cells line the ventricles and the central canal of the spinal cord and help circulate cerebrospinal fluid via cilia.