Parts of a neuron
Receive electrical signals (inputs) from other neurons or sensory cells.
Dendrites
Carry signals from sensory receptors (e.g., eyes, skin) to the central nervous system (CNS).
Sensory Neurons
Chemical messengers that transmit signals across the synapse between neurons. Common neurotransmitters include dopamine, serotonin, and acetylcholine.
Neurotransmitters
Involved in reward, motivation, pleasure, and motor control. Low levels are associated with Parkinson's disease and schizophrenia.
Dopamine
A brief electrical charge that travels down the axon, allowing a neuron to transmit a signal. It occurs when the neuron reaches a certain threshold of depolarization, causing ion channels to open and ions to flow across the membrane, creating a rapid change in electrical charge.
Action Potential
Contains the nucleus, which houses the genetic material. It integrates incoming signals from dendrites and controls the metabolic activities of the neuron.
Cell body/soma
Transmit signals from the CNS to muscles or glands to initiate action (e.g., muscle contraction).
Motor Neurons
The process by which neurotransmitters are reabsorbed by the presynaptic neuron after they have transmitted their signal. This process regulates the duration and intensity of the signal.
Reuptake
Regulates mood, appetite, and sleep. Imbalances can lead to depression, anxiety, and sleep disorders.
Serotonin
The minimum level of stimulation required to trigger an action potential. If the depolarization does not reach this threshold, the neuron does not fire.
threshold
Carries the electrical signal away from the cell body to other neurons, muscles, or glands. The axon can be very long, allowing signals to travel great distances.
Axon
Found in the CNS, these neurons connect sensory and motor neurons and play a key role in reflexes and complex processing.
Neurons communicate primarily through electrochemical signaling. Electrical signals (action potentials) travel down the axon and trigger the release of neurotransmitters at the synapse, which bind to receptors on the receiving neuron.
Neuron Communication
helps regulate arousal and alertness, and is involved in the fight-or-flight response.
Norepinephrine
The stable, negative charge of a neuron when it is not sending a signal. Typically, it is around -70 mV. This is maintained by ion channels and pumps that regulate the balance of sodium (Na+) and potassium (K+) ions inside and outside the neuron.
Resting Potential
Insulates the axon, speeding up the transmission of electrical impulses along the axon. It is formed by oligodendrocytes in the CNS and Schwann cells in the PNS.
Myelin Sheath
Name all types of neurons
Sensory, Motor, and Interneuron
Substances that mimic the action of a neurotransmitter by binding to its receptor and activating it, thus enhancing the neurotransmitter's effect. For example, morphine is an agonist for endorphins.
Agonists
also plays a role in the fight-or-flight response, increasing heart rate, blood flow, and energy production.
Epinephrine
The period of time after an action potential during which a neuron cannot fire another action potential. There is an absolute refractory period (no action potential can occur) and a relative refractory period (a stronger-than-usual stimulus is required to trigger an action potential).
Refractory Period
Release neurotransmitters into the synapse, which communicate with other neurons, muscles, or glands.
Terminal Branches of Axon
What is the function of neurons?
Responsible for receiving, processing, and transmitting electrical signals throughout the body.
Substances that block or inhibit the action of a neurotransmitter by binding to its receptor without activating it. For example, Botox is an antagonist for acetylcholine, preventing muscle contraction.
Antagonists
Involved in muscle movement and memory. It is the neurotransmitter at neuromuscular junctions and plays a critical role in the central nervous system, particularly in attention and learning.
Acetylcholine
Bernadette