neural impulse

Examples of neural impulse in the following topics:

• 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.
  • Neural impulses from sensory receptors are sent to the brain and spinal cord for processing.
  • After the brain has processed the information, neural impulses are then conducted from the brain and spinal cord to muscles and glands, which is the resulting motor output.
  • In addition, some poisons and drugs interfere with nerve impulses by blocking sodium channels in nerves.
  • Reuptake refers to the reabsorption of a neurotransmitter by a presynaptic (sending) neuron after it has performed its function of transmitting a neural impulse.

• Electrical Events

  • The SA and AV nodes initiate the electrical impulses that cause contraction within the atria and ventricles of the heart.
  • The SA node nerve impulses travel through the atria and cause muscle cell depolarization and contraction of the atria directly.
  • The SA node impulses also travel to the AV node, which stimulates ventricular contraction.
  • The AV node slows the neural impulse from the SA node by a slight amount, which causes a delay between depolarization of the atria and the ventricles.
  • The normal firing rate in the AV node is lower compared to the SA node because it slows the rate of neural impulses.

• Introduction to Sensation

  • ., light) into neural impulses.
  • These neural impulses enter the cerebral cortex of the brain, which is made up of layers of neurons with many inputs.
  • This fMRI chart shows some of the neural activation that takes place during sensation.

• Neural Networks

  • A neural network (or neural pathway) is the interface through which neurons communicate with one another.
  • These networks consist of a series of interconnected neurons whose activation sends a signal or impulse across the body.
  • The basic kinds of connections between neurons are chemical synapses and electrical gap junctions, through which either chemical or electrical impulses are communicated between neurons.
  • A neural network (or neural pathway) is the complex interface through which neurons communicate with one another.
  • 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.

• Short-Term Neural Control

  • Neural regulation of blood pressure is achieved through the role of cardiovascular centers and baroreceptor stimulation.
  • They send impulses to the cardiovascular centre to regulate blood pressure.
  • Other neural mechanisms can also have a significant impact on cardiovascular function.

• Development of the Peripheral Nervous System

  • The peripheral nervous system develops from two strips of tissue called the neural crest, running lengthwise above the neural tube.
  • At this point the future CNS appears as a cylindrical structure called the neural tube, whereas the future PNS appears as two strips of tissue called the neural crest, running lengthwise above the neural tube.
  • The sequence of stages from neural plate to neural tube and neural crest is known as neurulation .
  • After gastrulation, neural crest cells are specified at the border of the neural plate and the non-neural ectoderm.
  • During neurulation, the borders of the neural plate, also known as the neural folds, converge at the dorsal midline to form the neural tube.

• Embryonic Development

  • The neural groove gradually deepens as the neural folds become elevated, and ultimately the folds meet and coalesce in the middle line and convert the groove into a closed tube, the neural tube or neural canal, the ectodermal wall of which forms the rudiment of the nervous system.
  • Primary neurulation begins after the neural plate has formed.
  • The edges of the neural plate start to thicken and lift upward, forming the neural folds.
  • The center of the neural plate remains grounded allowing a U-shaped neural groove to form.
  • The neural folds pinch in towards the midline of the embryo and fuse together to form the neural tube.

• Neurulation

  • Neurulation is the formation of the neural tube from the ectoderm of the embryo.
  • The neural plate folds outwards to form the neural groove.
  • Beginning in the future neck region, the neural folds of this groove close to create the neural tube (this form of neurulation is called primary neurulation).
  • The hollow interior is called the neural canal.
  • Transverse sections that show the progression of the neural plate to the neural groove from bottom to top.

• A History of Theories of Consciousness

  • Theories of consciousness include developmental, cultural, neural, computational, and moral perspectives.
  • Much of what is stored in the unconscious is thought to be unpleasant or conflicting; for example, sexual impulses that are deemed unacceptable. 
  • Neuropsychologists view consciousness as ingrained in neural systems and organic brain structures.
  • A major part of the modern scientific literature on consciousness consists of studies that examine the relationship between the experiences reported by subjects and the activity that simultaneously takes place in their brains—that is, studies of the neural correlates of consciousness.

• Psychosurgery

  • Psychosurgery, a group of procedures aimed at disrupting neural pathways, has declined over the years due to better psychiatric medications.
  • Psychosurgery is a drastic step typically only taken in the absence of any other successful treatment (and sometimes not even then), because it is a major challenge to remove harmful tissue without impacting the brain tissue necessary to retain full neural function.
  • In deep-brain stimulation (DBS), a device like a pacemaker is implanted into a part of the brain to send electrical impulses to that area of the brain.
  • Psychiatric medications also are able to provide effective treatment in a number of other ways, such as stimulating neural pathways.