M12: General Sensation

What is the difference between sensation and perception?

Sensation is the process of sensing our environment through touch, taste, sight, sound, and smell, while perception is assigning meaning to that sensory information.

What are the two main classifications of sensory receptors based on location?

Exteroceptors (respond to external stimuli) and interoceptors (respond to internal stimuli).

What type of sensory receptor responds to changes in temperature?

Thermoreceptors.

What do nociceptors sense?

Tissue damage, physical trauma, or thermal injury.

What is sensory adaptation?

The loss of responsiveness at the sensory receptor level in the presence of constant stimulus.

What is a sensory unit?

The sensation generated by a sensory neuron and all its receptors.

What is the relationship between stimulus strength and sensory unit activation?

Stronger stimuli activate more sensory units, increasing both action potential frequency and the number of sensory units activated.

What are the two main somatosensory pathways?

The dorsal column pathway (detects fine touch and proprioception) and the anterolateral pathway (conveys pain and temperature information).

What is the role of the dorsal root ganglion in sensory pathways?

It contains the cell bodies of sensory neurons that transmit information to the spinal cord.

What are the features of the dorsal column pathway?

It detects fine touch and proprioception, with sensory neurons synapsing in the medulla and third-order neurons projecting to the somatosensory cortex.

What are the features of the anterolateral pathway?

It conveys pain and temperature information, with sensory neurons synapsing in the dorsal horn and third-order neurons projecting to the somatosensory cortex.

What are endogenous opioids?

Chemicals produced by the body that modulate pain, such as β-endorphins and enkephalins.

What is the function of analgesics?

They modify the perception of pain.

What is the role of TRP channels in thermoreception?

They open at different temperatures to release Ca2+ and detect temperature changes.

What is referred pain?

Pain perceived at a location other than the site of the painful stimulus.

What happens to sensory receptors with senescence?

There is declining sensitivity, increased thresholds for action potential generation, and decreased response to stimuli.

What are mechanoreceptors responsible for?

Sensing mechanical stress, pressure changes, and body position.

What type of interoceptors detect changes within internal organs?

Visceral interoceptors.

What are somatic interoceptors?

Interoceptors found within musculoskeletal structures that detect body interactions with the environment.

What is the significance of sensory receptor physiology?

It describes how sensory information is converted from analog signals to digital action potentials.

What are the types of pain recognized by nociceptors?

Fast pain, slow pain, acute pain, chronic pain, and visceral pain.