Nicoletta Quiz 2023: Nervous Tissue

Study Notes

Nervous Tissue

Astrocytes are specialized neurons involved in numerical cognition.
Neurons do not possess mitochondria and typically store but do not synthesize neurotransmitters.
Schwann cells are responsible for forming the myelin sheath, which is mainly associated with the peripheral nervous system.

Neurons and Their Extensions

Axons feature spines where numerous synaptic contacts are formed.
Neuronal extensions are categorized into axons, dendrites, and myofibrils.
In multipolar neurons, axons are generally the shortest extensions.
Axons in gray matter do not have a myelin sheath.

Membrane Potential

Ion movement across the neuronal membrane occurs through protein-formed channels.
Some ionic channels open in response to changes in the electrical potential of the membrane.
The sodium-potassium pump transfers potassium ions outside the cell and sodium ions into the cell.
Sodium ions can diffuse freely through the lipid bilayer of the neuronal membrane without the need for channels.

Action Potential

The amplitude of action potentials decreases with increasing distance from the generation site.
Sodium ions enter the cell during the depolarization phase of the action potential.
The intensity of a stimulus is reflected in the amplitude of action potentials.
The repolarization phase is characterized by potassium ions moving outside the cell.

Synapses

Excitatory synapses trigger depolarization of the postsynaptic membrane.
Electrical synapses can exhibit functional symmetry.
In chemical synapses, neurotransmitter release occurs 0.5 milliseconds prior to the action potential reaching the synaptic terminal.
Neurotransmitters diffuse across the synaptic cleft after being released.

Vestibular System

The vestibular system is crucial for maintaining balance.
Head rotation leads to movement of endolymph in the semicircular canals.
Otoliths from the saccule and utricle provide signals related to posture and gravity.
Ciliated cells in the semicircular canals are housed within a structure known as otoconia.

Description

Test your knowledge on the structures and functions of the nervous tissue with this Nicoletta quiz. Explore questions about neuron characteristics, types of glial cells, and their roles in the central nervous system. See how much you know about the intricate details of neuronal functioning!