In-Depth Notes on Sensory Receptors and Functions

Receptors and Sensory Functions

Types of Receptors

• Mechanoreceptors:

  • Responds to mechanical forces.
  • Examples include touch, pressure, stretch, vibration, and itch.
  • Baroreceptors: A type of mechanoreceptor that monitors blood pressure.

• Thermoreceptors:

  • Responds to changes in temperature.

• Chemoreceptors:

  • Responds to chemical substances, important for the senses of taste and smell.

• Photoreceptors:

  • Responds to light and are primarily located in the eyes.

• Nociceptors:

  • Responds to harmful stimuli that result in pain.

General Somatic vs. Visceral Sensory Functions

• General Somatic Sensory:

  • Responsible for sensations such as:
  • Touch
  • Pressure
  • Vibration
  • Temperature
  • Pain
  • Proprioception (awareness of body position)

• General Visceral Sensory:

  • Responds to sensations related to internal organs such as:
  • Stretch
  • Pressure
  • Pain
  • Chemical changes
  • Hunger and thirst

Receptors and Components of Gustatory Sense

• Taste Receptors:
  • Located primarily in taste buds situated on the surface of the tongue and within tongue papillae.
  • There are five basic qualities of taste:
  • Sweet
  • Sour
  • Salty
  • Bitter
  • Umami (elicited by glutamate)

Receptors and Components of Olfactory Sense

• Olfactory Receptors:
  • Located in the olfactory epithelium.
  • Olfactory Cilia: Act as receptive structures for the sense of smell.
• Pathway:
  • Axons of olfactory sensory neurons penetrate the cribriform plate of the ethmoid bone.
  • These axons enter the olfactory bulbs and synapse with mitral cells.
  • Mitral Cells:
  • Transmit impulses along the olfactory tract to the primary olfactory cortex located in the temporal lobe.