Somatic Senses Quiz: Classification and Types

• The non-hairy parts of the skin, including fingertips and lips, have receptors that detect tactile sensations under the categories of touch, pressure, and vibration.

• Meissner's corpuscles are tactile receptors with expanded tips that detect touch sensation and initial contact with the body, while Merkel's discs in hairy skin detect slight movement of hairs and initial contact.

• Ruffini's endings are multibranched, encapsulated nerve endings that detect continuous states of deformation, such as heavy prolonged touch and pressure.

• Pacinian corpuscles are located beneath the skin and deep in the fascial tissues and detect vibration sensations.

• Almost all specialized sensory receptors transmit signals via A-beta nerve fibers, which have a velocity of 30 to 70 m/sec. Free nerve endings transmit signals via Delta-A myelinated fibers, which have a velocity of 5-30 m/sec.

• The dorsal column–medial lemniscal system and the anterolateral system are two sensory pathways that transmit somatic signals to the central nervous system. The dorsal column–medial lemniscal system carries signals for fine touch sensations, position sensations from joints, and vibratory sensations, while the anterolateral system carries signals for pain, thermal sensations, crude touch and pressure sensations, tickle and itch sensations, and sexual sensations.

• The dorsal column–medial lemniscal system enters the spinal cord through the dorsal roots and continues to the thalamus, while the anterolateral system enters the spinal cord from the dorsal roots, synapses in the dorsal horns, and terminates at all levels of the lower brain stem and in the thalamus.

• The somatosensory cortex has 50 distinct areas, called Brodmann's areas, based on histological structural differences. It consists of six layers of neurons, each with a different function, including receiving incoming sensory signals and sending signals to related parts of the brain or deeper parts of the nervous system.

• Layers I and II of the somatosensory cortex receive diffuse, nonspecific input signals that facilitate specific regions of the cortex.

• The dorsal column–medial lemniscal system projects through the thalamus to the somatosensory cortex, which interprets and processes the sensory information. The anterolateral pathway transmits less critical sensory signals, including pain, heat, cold, and crude touch and pressure sensations.

• The anterolateral sensory pathway has anterior and lateral divisions. The anterior division carries pain and temperature sensations from the body, while the lateral division carries tactile information from the limbs.

• The non-hairy parts of the skin, including fingertips and lips, have receptors that detect tactile sensations under the categories of touch, pressure, and vibration.

• Meissner's corpuscles are tactile receptors with expanded tips that detect touch sensation and initial contact with the body, while Merkel's discs in hairy skin detect slight movement of hairs and initial contact.

• Ruffini's endings are multibranched, encapsulated nerve endings that detect continuous states of deformation, such as heavy prolonged touch and pressure.

• Pacinian corpuscles are located beneath the skin and deep in the fascial tissues and detect vibration sensations.

• Almost all specialized sensory receptors transmit signals via A-beta nerve fibers, which have a velocity of 30 to 70 m/sec. Free nerve endings transmit signals via Delta-A myelinated fibers, which have a velocity of 5-30 m/sec.

• The dorsal column–medial lemniscal system and the anterolateral system are two sensory pathways that transmit somatic signals to the central nervous system. The dorsal column–medial lemniscal system carries signals for fine touch sensations, position sensations from joints, and vibratory sensations, while the anterolateral system carries signals for pain, thermal sensations, crude touch and pressure sensations, tickle and itch sensations, and sexual sensations.

• The dorsal column–medial lemniscal system enters the spinal cord through the dorsal roots and continues to the thalamus, while the anterolateral system enters the spinal cord from the dorsal roots, synapses in the dorsal horns, and terminates at all levels of the lower brain stem and in the thalamus.

• The somatosensory cortex has 50 distinct areas, called Brodmann's areas, based on histological structural differences. It consists of six layers of neurons, each with a different function, including receiving incoming sensory signals and sending signals to related parts of the brain or deeper parts of the nervous system.

• Layers I and II of the somatosensory cortex receive diffuse, nonspecific input signals that facilitate specific regions of the cortex.

• The dorsal column–medial lemniscal system projects through the thalamus to the somatosensory cortex, which interprets and processes the sensory information. The anterolateral pathway transmits less critical sensory signals, including pain, heat, cold, and crude touch and pressure sensations.

• The anterolateral sensory pathway has anterior and lateral divisions. The anterior division carries pain and temperature sensations from the body, while the lateral division carries tactile information from the limbs.

Test your knowledge of somatic senses, including touch, pressure, temperature, and pain. Learn about the 3 physiologic types of somatic senses and the nervous mechanisms involved in collecting sensory information from the body.