Neuron Structure
This part of the neuron houses the nucleus, Golgi apparatus, and rough endoplasmic reticulum, synthesizing large amounts of proteins.
What is the soma (cell body)?
The electrical potential difference across a cell membrane when the cell is not actively sending signals, typically –70 mV
What is the resting membrane potential?
In the central nervous system, these cells myelinate multiple axons and speed conduction of electrical impulses.
What are oligodendrocytes?
This acute inflammatory demyelinating condition often follows a mild infection, causing ascending muscle weakness that can lead to complete paralysis.
What is Guillain-Barré Syndrome?
This occurs when a neurotransmitter binds to a receptor on the postsynaptic
membrane, causing ion channels to open and allowing ions to flow in or out,
changing the cell's electrical charge. It causes local depolarization.
What is postsynaptic potential?
These branch-like extensions receive synaptic input from other neurons.
What are dendrites?
This small change in a neuron’s membrane voltage can diminish over a short distance and is not all-or-none.
What is a local (graded) potential?
Providing myelin in the peripheral nervous system, these cells can only wrap one axon segment each.
What are Schwann cells?
An autoimmune attack on oligodendrocytes results in plaques in the CNS, with symptoms like muscle weakness, spasticity, vision problems, and possible cognitive changes.
What is multiple sclerosis (MS)?
This neurotransmitter regulates sleep, appetite, arousal, and mood. Inadequate levels of this neurotransmitter result in depression, anxiety, OCD if it is too little. It may result in Schizophrenia if it is too much.
What is serotonin?
Known as the output unit of a neuron, it transmits signals away from the cell body to other neurons or muscles.
What is an axon?
Once threshold is reached, this large depolarization travels the length of the axon without losing strength.
What is an action potential?
Star-shaped cells that contribute to the blood-brain barrier, regulate extracellular ions, and provide structural support.
What are astrocytes?
When the same sensory neuron sends signals that activate numerous motor neurons for a quick reaction to pain, it illustrates this neural principle.
What is divergence?
The main inhibitory neurotransmitter in the CNS, often causing hyperpolarization of the postsynaptic membrane.
What is GABA (gamma-aminobutyric acid)?
These specialized endings release neurotransmitters into the synaptic cleft to communicate with the next cell.
What are presynaptic terminals?
This enzyme pump removes three sodium ions for every two potassium ions imported, helping maintain the resting membrane potential.
What is the Na+/K+ ATPase (sodium-potassium pump)?
These small yet powerful immune cells act as the CNS’s first line of defense, cleaning up debris and responding to injury.
What are microglia?
This is any pathologic change involving peripheral
nerves. It often involves the destruction of the myelin surrounding the largest, most myelinated sensory and motor fiber. It results in disrupted proprioception (awareness of limb position) and weakness
What is peripheral neuropathy?
These transporter proteins pull neurotransmitters back into the presynaptic terminal, allowing them to be recycled or broken down.
What are reuptake transporters?
These proteins embedded in the plasma membrane are always open to potassium ions, contributing significantly to the negative resting membrane potential.
What are leaky (K+) channels?
A neuron’s interior becomes more negative than its resting potential during this process, making it harder to generate an action potential.
What is hyperpolarization?
Excessive or abnormal activation of these cells is linked to harmful neuroinflammation in conditions such as Alzheimer’s, Parkinson’s, and multiple sclerosis.
What are microglia (when overactive) or abnormal glial cells?
This autoimmune disorder destroys acetylcholine receptors at the neuromuscular junction, leading to fluctuating and often worsening muscle weakness.
What is myasthenia gravis?
This neurotransmitter, crucial for regulating movement in the basal ganglia, motivation, and reward pathways, is associated with disorders such as Parkinson’s disease (too little) and schizophrenia (too much).
What is dopamine?