Chapter 12 Flashcards
Mechanoreceptors
Sensory receptors that transducer mechanical deformations of the skin in neural signals that are sent to the brain
SAI mechanoreceptors
Slow-adapting mechanoreceptors with Merkel cell endings; they have relatively small receptive fields and are relatively densely arranged near the surface of the skin
SAII mechanoreceptors
Slow-adapting mechanoreceptors; they have relatively large receptive fields and are relatively sparsely distributed relatively deeply in the skin
FAI mechanoreceptors
Fast adapting mechanoreceptors and Meissner corpuscle endings
FAII mechanoreceptors
Fast-adapting mechanoreceptors with pacinian corpuscle endings; they have relatively large receptive fields and are relatively sparsely distributed relatively deeply in the skin
Merkel cells
Specialized endings of SAI mechanoreceptors, where transduction takes place
Meissner Corpuscles
Specialized in mints of FAI mechanoreceptors, where transduction takes place
Pacinian corpuscles
Specialized endings of FAII receptors, where transduction takes place
C-tactile mechanoreceptors
Mechanoreceptors that are a type of free nerve endings only present on hairy skin, they responds to slow, gentle touch and send signals to the insular cortex
Proprioception
Perception of the position and movement of body parts, based on the information in neural signals from specialized sensors within those body parts
Muscle spindles
Sensory organs that provide information about muscle length, as well as information about isometric forces on muscles, for proprioception
Golgi tendon organs
Sensory organs that provide information about muscle force for proprioception
Joint receptors
Sensory organs that provide information about joint angle, probably to signal when a joint had reached the limit of its normal motion
Pain
An unpleasant sensory and emotional experience caused by potential or actual tissue damage, pain can arise from a wide range of different causes and can evoke an equally wide range of perceptual experiences
Nocioception
The perception of pain
Nocioceptive pain
Pain that arises from tissue damage due to physical trauma
Nocioceptors
Sensory receptors that transduce the physical stimuli associated with damaging mechanical, thermal, or chemical events, included among th free nerve endings in the epidermis and dermis
Sensitization
A mechanism that decreases the response threshold of nocioceptors, so that even very low level stimulation of an injury site can cause pain
A-delta fibers
Myelinated axons of nocioceptors that transmit pain signals relatively rapidly. To produce a rapid response to potentially damaging mechanical stimuli and to excessive heat
C fibers
Unmyelinated axons of nocioceptors that transmit pain signals relatively slowly.
Thermoreception
The ability to sense the temperature of objects and surfaces in contact with the skin
Tactile perception
Perception that results from the mechanical deformation indentation, vibration, or stretching
Warm fibers
Thermoreceptors that fire at an ongoing moderate rate in response to sustained skin temperatures in the range of 29-43 C
Cold Fibers
Thermoreceptors that fire at an ongoing moderate rate in response to sustained skin temperatures in the range of 17-40 C
Dorsal column-medial lemniscal pathway
Pathway for signals involved in tactile perception and proprioception; travels up the spinal cord on the ipsilateral side, crosses to the contralateral side in the medulla, and then goes through the ventral posterior nucleus of the thalamus and on to the somatosensory cortex
Spinothalamic
Pathway for signals involved in nocioception and themoreception
Ventral posterior nucleus
A nucleus of the thalamus part of both the DCML pathway and the spinothalamic pathway
Somatosensory cortex
A region of the cerebral cortex in the anterior parietal lobe; receives signals carrying sensory information via the ventral posterior nucleus of the thalamus
Primary somatosensory cortex
A subregion of the somatosensory cortex, the first sea to receive somatosensory signals from the ventral posterior nucleus of the thalamus
Secondary somatosensory cortex
A subregion of the somatosensory cortex; receives signals from area S1
Somatotopic map
A mapping of the body surface onto the somatosensory cortex; whereby adjacent locations on the cortex receive somatosensory signals from adjacent locations on the body
Endogenous opioids
Compounds that belong to a class of substances called opiates: released by the body in response to painful or stressful experiences
Endorphins
Endogenous opioids that have an inhibitory effect on pain-related neural signals in many areas of the central nervous system, reducing the perceived intensity of pain.
Cortical plasticity
The ability of the adult cortex to change the way it’s organized
Haptic perception
Actively using touch to perceive and identify objects by their 3D shape and other material properties; involves the integration of information from tactile perception, proprioception, and thermoreception
Exploratory procedures
Hand and finger movements typically used by people to identify objects haptically
Tactile agnosia
An inability to recognize objects by touch, which can result from damage to the parietal cortex, specifically to area S2
Vestibular system
The sense organs used to produce neural signals carrying information about balance and acceleration; includes the semicircular canals and the otolith organs
Semicircular canals
Part of the vestibular system; three mutually perpendicular hollow curved tubes in the skull filled with endolymph; responsible for signaling head rotation
Otolith organs
Part of the vestibular system; consist of the utricle and the saccule; responsible for signalling when the head is undergoing linear acceleration or being held in a tilted position
Vestibule-ocular reflex
An unconscious compensating movement of the eyes during head movements in order to maintain a stable gaze
