signal

Examples of signal in the following topics:

• Introducing the Neuron

  • Neurons are specialized cells that transmit chemical and electrical signals.
  • This is the basic chain of neural signal transmission, which is how the brain sends signals to the muscles to make them move, and how sensory organs send signals to the brain.
  • It is important that these signals can happen quickly, and they do.
  • This is because the sense organ (in this case, the skin) sends the signal "This is hot!"
  • At these nodes, the signal is "recharged" as it travels along the axon.

• Stages of the Action Potential

  • Neural impulses occur when a stimulus depolarizes a cell membrane, prompting an action potential which sends an "all or nothing" signal.
  • A neurotransmitter can be thought of as a key, and a receptor as a lock: the key unlocks a certain response in the postsynaptic neuron, communicating a particular signal.
  • "Resting potential" is the name for the electrical state when a neuron is not actively being signaled.
  • Therefore, action potentials are said to be all-or-none signals, since either they occur fully or they do not occur at all.
  • Reuptake is necessary for normal synaptic physiology because it allows for the recycling of neurotransmitters and regulates the neurotransmitter level in the synapse, thereby controlling how long a signal resulting from neurotransmitter release lasts.

• The Endocrine System and Hunger

  • It involves neural signals from the GI tract, blood levels of nutrients, and GI-tract hormones.
  • The brain can evaluate the contents of the gut through vagal nerve fibers that carry signals between the brain and the gastrointestinal (GI) tract.
  • They send signals along the vagus nerve afferent pathway and ultimately inhibit the hunger centers of the hypothalamus.
  • Nutrient signals indicate fullness.
  • Ghrelin, a hormone produced by the stomach, triggers the release of orexin from the hypothalamus, signaling to the body that it is hungry.

• Olfaction: The Nasal Cavity and Smell

  • The olfactory system gives humans their sense of smell by collecting odorants from the environment and transducing them into neural signals.
  • These proteins carry out the transduction of odorants into electrical signals for neural processing.
  • These chemical signals are transformed into electrical signals and sent to the brain, where they are perceived as smells.
  • In mammals, olfactory receptors have been shown to signal via G protein.
  • This is a similar type of signaling of other known G protein-coupled receptors (GPCR).

• Neural Networks

  • These networks consist of a series of interconnected neurons whose activation sends a signal or impulse across the body.
  • If a stimulus creates a strong enough input signal in a nerve cell, the neuron sends an action potential and transmits this signal along its axon.
  • The basic neuronal function of sending signals to other cells includes the capability for neurons to exchange signals with each other.
  • In this conception, neural processing begins with stimuli that activate sensory neurons, producing signals that propagate through chains of connections in the spinal cord and brain, giving rise eventually to activation of motor neurons and thereby to muscle contraction or other overt responses.
  • Neurons interact with other neurons by sending a signal, or impulse, along their axon and across a synapse to the dendrites of a neighboring neuron.

• Somatosensation: Pressure, Temperature, and Pain

  • There are two types of thermoreceptors that signal temperature changes in our own skin: warm and cold receptors.
  • Pain signals can be separated into three types that correspond to the different types of nerve fibers used for transmitting these signals.
  • This type of signal is easy to locate and generally easy to tolerate.
  • This signal is more difficult to locate and not as easy to tolerate.
  • This type of signal is very difficult to locate, and often it is intolerable and chronic.

• Human vs. Animal Language

  • Some animals use signs, signals, or sounds to communicate.
  • Communication in both animals and humans consists of signals.
  • Signals are sounds or gestures that have some meaning to those using them.
  • Human communication consists of both signals and symbols.
  • Symbols, unlike signals, must be taught and learned; they are not instinctual or self-evident.

• Vision: The Visual System, the Eye, and Color Vision

  • In the human visual system, the eye receives physical stimuli in the form of light and sends those stimuli as electrical signals to the brain, which interprets the signals as images.
  • Photoreceptor cells found in this region have the specialized capability of phototransduction, or the ability to convert light into electrical signals.
  • Sophisticated combinations of these receptors signals are transduced into chemical and electrical signals, which are sent to the brain for the dynamic process of color perception.

• Neurotransmitters

  • Neurotransmitters are chemicals that transmit signals from a neuron across a synapse to a target cell.
  • Neurotransmitters are chemicals that transmit signals from a neuron to a target cell across a synapse.
  • This allows the signal to pass through the neuron.

• Brain Imaging Techniques

  • .), both the frequency and the form of the EEG signal differ.
  • Because of this, it is sometimes unclear exactly which region of the brain is emitting a signal.
  • An MRI uses strong magnetic fields to align spinning atomic nuclei (usually hydrogen protons) within body tissues, then disturbs the axis of rotation of these nuclei and observes the radio frequency signal generated as the nuclei return to their baseline status.
  • Specifically, the fMRI measures signal changes in the brain that are due to changing neural activity.