sensory receptor

Examples of sensory receptor in the following topics:

• Classification of Receptors by Stimulus

  • Sensory receptors can be classified by the type of stimulus that generates a response in the receptor.
  • Broadly, sensory receptors respond to one of four primary stimuli:
  • Sensory receptors perform countless functions in our bodies.
  • Cutaneous receptors are sensory receptors found in the dermis or epidermis.
  • A tonic receptor is a sensory receptor that adapts slowly to a stimulus, while a phasic receptor is a sensory receptor that adapts rapidly to a stimulus.

• Classification of Receptors by Location

  • Some sensory receptors can be classified by the physical location of the receptor.
  • Remarkably, specialized receptors have evolved to transmit sensory inputs from each of these sensory systems.
  • Sensory receptors code four aspects of a stimulus:
  • Sensory receptors are found throughout our bodies, and sensory receptors that share a common location often share a common function.
  • For example, sensory receptors in the retina are almost entirely photoreceptors.

• Functions of the Nervous System

  • These functions are based on the sensory input,  integration and motor output.
  • Sensory input is based on the many sensory receptors that can monitor changes occurring both inside and outside the body.
  • The total sum of the gathered information by these sensory receptors is called sensory input.
  • It does this by extracting information from the environment using sensory receptors.
  • When this signal reaches a synapse, it provokes release of neurotransmitter molecules, which bind to receptor molecules located in the the target cell.

• Transduction and Perception

  • This takes place at the sensory receptor.
  • How is sensory input, such as pressure on the skin, changed to a receptor potential?
  • Sensory receptors for the various senses work differently from each other.
  • Although perception relies on the activation of sensory receptors, perception happens, not at the level of the sensory receptor, but at the brain level.
  • The brain distinguishes sensory stimuli through a sensory pathway: action potentials from sensory receptors travel along neurons that are dedicated to a particular stimulus.

• Reception

  • In one, a neuron works with a sensory receptor, a cell, or cell process that is specialized to engage with and detect a specific stimulus.
  • Stimulation of the sensory receptor activates the associated afferent neuron, which carries information about the stimulus to the central nervous system.
  • In the second type of sensory transduction, a sensory nerve ending responds to a stimulus in the internal or external environment; this neuron constitutes the sensory receptor.
  • The first step in sensation is reception: the activation of sensory receptors by stimuli such as mechanical stimuli (being bent or squished, for example), chemicals, or temperature.
  • The region in space in which a given sensory receptor can respond to a stimulus, be it far away or in contact with the body, is that receptor's receptive field.

• Integration of Signals from Mechanoreceptors

  • The nociceptive receptors (those that detect pain) are located near the surface.
  • During the transmission of sensory information from these fields, the signals must be conveyed to the nervous system.
  • If the two points are felt as one point, it can be inferred that the two points are both in the receptive field of a single sensory receptor.
  • If two points are felt as two separate points, each is in the receptive field of two separate sensory receptors.
  • Structure of four different types of sensory receptors found within the sensory system.

• Cutaneous Sensation

  • The somatosensory system is composed of the receptors and processing centers to produce the sensory modalities, such as touch and pain.
  • Spread through all major parts of the body, it consists of sensory receptors and sensory neurons in the periphery (for example, skin, muscle, and organs), along with deeper neurons within the central nervous system.
  • Transmission of information from the receptors passes via sensory nerves through tracts in the spinal cord and into the brain.
  • Upon deviation from the norm ,sensory receptors trigger an action potential that can provide feedback or lead to alterations in behavior in order to maintain homoeostasis.
  • Mechanoreceptors are sensory receptors that respond to pressure and vibration.

• Sensory Adaptation

  • Sensory adaptation is the decrease in the responsiveness of a sensory system that is confronted with a constant stimulus.
  • Sensory adaptation, also called neural adaptation, is the change in the responsiveness of a sensory system that is confronted with a constant stimulus.
  • One example of sensory adaptation is sustained touching.
  • When you rest your hands on a table or put clothes on your body, at first the touch receptors will recognize that they are being activated and you will feel the sensation of touching an object.
  • However, after sustained exposure, the sensory receptors will no longer activate as strongly and you will no longer be aware that you are touching something.

• Sensory-Somatic Nervous System

  • The sensory-somatic nervous system transmits sensory information from the body to the brain and motor movements from the brain to the body.
  • The sensory-somatic nervous system is composed of cranial and spinal nerves and contains both sensory and motor neurons.
  • Sensory neurons transmit sensory information from the skin, skeletal muscle, and sensory organs to the central nervous system (CNS).
  • Each sensory neuron has one projection with a sensory receptor ending in skin, muscle, or sensory organs, and another that synapses with a neuron in the dorsal spinal cord.
  • Spinal nerves contain both sensory and motor axons.

• Sensory Modalities

  • The sensory modality for vision is light.
  • The sensory modality for audition is sound.
  • It collects and sends these vibrations to receptor cells.
  • The vestibular nerve conducts information from sensory receptors in three ampulla, each of which sense fluid motion in three semicircular canals caused by a three-dimensional rotation of the head.
  • There are specialized receptors for cold (declining temperature) and heat.