FoundationalConceptsNeuroscience

sensitivity of the basilar membrane, making it more sensitive to low- volume sounds. The outer hair cells contain a protein call ...

—exposure to loud sounds. The standard way of measuring sound intensity, or loudness, is a unit called the decibel (dB), named i ...

tutes chronic acoustic trauma and may result in permanent hearing loss. Time will tell whether the vastly increased use of porta ...

hearing aids consist of a microphone and amplifier, which either sit behind or within the pinna, and a small tube that directs t ...

of three orthogonal (spatially perpendicular, at 90-degree angles to one another) semicircular canals, together with two bulbous ...

in the fluid above the hair cells. As the body accelerates or changes orientation with respect to gravity, the inertia of these ...

CHAPTER 1 6 Skin, Touch, and Movement Our skin is our largest sensory organ. Dendrites of somatosensory (Greek soma = body) neur ...

Free nerve endings Meissner’s Merkel’s corpuscle disks —~_ \ Ruffini endings Pacinian corpuscle Figure 16.1. Cross section of sk ...

DRG cell body ae Saaee iC Wh M \ Dendrite with Axon to spinal cord somatosensory receptors and brainstem Figure 16.2. Dorsal roo ...

along the axon into the central nervous system. A DRG dendrite func- tions just like an axon, except that action potentials prop ...

Central sulcus \ Postcentral gyrus Parietal lobe Figure 16.3. Primary somatosensory cortex (S1) is located in the anterior parie ...

actual body—the foot is connected to the leg is connected to the hip is connected to the torso is connected to the neck is conne ...

portional representation for various parts of the body. Another notable feature of the cortical map is that it does not have the ...

time. You will find that, when the U is touching the fingertips or the lips, the ends of the U can be very close together—perhap ...

which touch sensation is intact but is usually ignored or not recog- nized unless one’s attention is specifically drawn to it. M ...

An analogous process can happen in humans. Sometimes as a result of accident or disease a person may lose an arm or leg. Often i ...

Figure 16.5. Representation of the person’s phantom hand on both the cheek and the stump at the shoulder where the amputation oc ...

test this was carried out by V. S. Ramachandran, a neuroscientist at the University of California, San Diego. Touching an ampute ...

partial paralysis. For example, a lesion from a stroke that produced significant damage to the right posterior frontal lobe woul ...

rons in the premotor areas of the frontal lobes that are active during particular movements and also active when these movements ...