| A | B |
|---|
| Extroceptive Receptors | Detect stimulation of body surface structures |
| Free nerve endings | exist as dermal plexuses coiled around skin hair follicles |
| Meissner’s corpuscles | are very sensitive to light touch and low frequency vibration |
| Hair end-organ | detects light movement |
| Merkel’s disks | aregrouped into Iggo dome receptors |
| Ruffini endings | detect stretchare and are found deep in dermal plexuses |
| Pacinian corpuscles | respond very rapidly to any degree of deformations |
| low-frequency vibrations from 2 up to 80 cycles per second | could be detected easly by Meissner's corpuscles |
| signal vibrations from 30 to 800 cycles per second | could be detected easly by the Pacinian corpuscles |
| Tickling and itch sensations | are detected by free nerve endings in the skin |
| The dorsal column-medial lemniscal system is composed of | large, myelinated nerve fibers that transmit signals to the brain at velocities of 30 to 110 m/sec |
| anterolateral system is composed of | small myelinated fibers that transmit signals at velocities ranging from a few meters per second up to 40 m/sec |
| Nerve fibers of the dorsal columns synapse and cross to the opposite side in | the medulla |
| Nerve fibers of the anterolateral system synapse in the dorsal horns and | cross to the opposite side of the cord |
| Sensations judging fine degrees of pressure | travel in the DC-ML system |
| Sexual sensations | travel in the anterolateral system |
| Fibers from the lower parts of the body lie in | the center of the cord |
| The body left side is represented in . | the right side of the thalamus |
| The primary somatosensory cortex corresponds to | Brodmann's areas 3, 1, and 2. |
| SI | has six layers |
