QCM : Neuroanatomy and Disease Fundamentals — 10 questions

Explication

The nervous system's structure primarily consists of the central nervous system (brain and spinal cord) and the peripheral nervous system (all nerves outside the CNS). It is composed of neurons, which transmit signals, and glial cells, which support and insulate neurons. Therefore, the most complete description of its structure includes both the CNS and PNS, along with neurons and glial cells.

Explication

Glial cells do not transmit electrical signals; instead, they support neurons by providing insulation, nutrients, and structural support, which is essential for proper nervous system function.

Explication

Oligodendrocytes are the glial cells responsible for forming the myelin sheath in the central nervous system, while Schwann cells perform this function in the peripheral nervous system. This distinction is explicitly mentioned in the content, making it a concrete and verifiable fact.

Explication

Schwann cells are responsible for myelinating axons in the PNS, whereas oligodendrocytes perform this function in the CNS. Astrocytes and microglia have different supportive and immune roles.

Explication

Risk factors like hypertension and atrial fibrillation do not directly cause neuronal death but play a crucial role in increasing the likelihood of stroke occurrence. Hypertension can lead to vessel rupture or atherosclerosis, contributing to hemorrhagic or ischemic strokes, respectively. Atrial fibrillation increases the risk of embolic ischemic strokes by promoting clot formation in the heart that can travel to cerebral arteries. Therefore, their primary function in this context is to elevate the risk of stroke by contributing to the underlying vascular pathologies.

Explication

Dendrites are specialized to receive electrical signals from other neurons, whereas axons conduct the signals away from the cell body.

Explication

The Nobel Prize in Physiology or Medicine was awarded in 1906 to Camillo Golgi and Santiago Ramón y Cajal for their work on neuron structure, including the understanding of myelin sheaths' role in nerve conduction.

Explication

The myelin sheath insulates axons, enabling saltatory conduction, which significantly increases the speed of electrical signals.

Explication

Microglia are the immune cells of the CNS, responsible for defense against pathogens and clearing debris, unlike astrocytes, oligodendrocytes, and Schwann cells.

Explication

The synapse is the junction where two neurons communicate, allowing electrical or chemical signals to pass from one neuron to another.