Chapter 12 Flashcards
(27 cards)
Agnosia
The inability to recognize objects, even though simple sensory skills appear to be normal; most commonly caused by damage to posterior parietal areas of the brain.
Anaglesia
The absence of normal sensations of pain.
Dermatome
A region of skin innervated by the pair of dorsal roots from one spinal segment.
Dorsal Column
A white matter tract on the dorsal side of the spinal cord, carrying touch and proprioceptive axons to the brain stem.
Dorsal Column-Medial Lemniscal Pathway
An ascending somatic sensory pathway that mediates information about touch, pressure, vibration, and limb proprioception.
Endorphin
One of many endogenous opioid peptides with actions similar to those of morphine; present in many brain structures, particularly those related to pain.
Hyperalgesia
A reduced threshold for pain, an increased response to painful stimuli, or a spontaneous pain that follows localized injury.
Inflammation
A natural protective response of tissues to harmful stimuli. The cardinal signs of inflammation in skin include heat, redness, swelling, and pain.
Mechanoreceptor
Any sensory receptor selective for mechanical stimuli, such as hair cells of the inner ear, various receptors of the skin, and stretch receptors of skeletal muscle.
Medial Lemniscus
A white matter tract of the somatic sensory system carrying axons from dorsal column nuclei to the thalamus.
Neglect Syndrome
A neurological disorder in which a part of the body or a part of the visual field is ignored or suppressed; most commonly associated with damage to posterior parietal areas of the brain.
Nociceptor
Any receptor selective for potentially harmful stimuli; may induce sensations of pain.
Opioid Receptor
A membrane protein that selectively binds natural (e.g., endorphin) and synthetic (e.g., morphine) opioid substances.
Opioids
A class of drugs, including morphine, codeine, and heroin, that can produce analgesia as well as mood changes, drowsiness, mental clouding, nausea, vomiting, and constipation.
Pacinian Corpuscle
A mechanoreceptor of the deep skin, selective for high-frequency vibrations.
Periaqueductal Gray Matter (PAG)
A region surrounding the cerebral aqueduct in the core of the midbrain, with descending pathways that can inhibit the transmission of pain-causing signals.
Posterior Parietal Cortex
The posterior region of the parietal lobe, mainly Brodmann’s areas 5 and 7, involved in visual and somatosensory integration and attention.
Primary Somatosensory Cortex
Brodmann’s area 3b located in the postcentral gyrus; also called S1.
Referred Pain
Pain that is perceived as coming from a site other than its true origin. Nociceptor activation within visceral organs is typically perceived as pain originating in skin or skeletal muscle.
Somatic Sensation
The senses of touch, temperature, body position, and pain.
Somatotopy
The topographic organization of somatic sensory pathways in which neighboring receptors in the skin feed information to neighboring cells in a target structure.
Spinal Segment
One set of dorsal and ventral roots plus the portion of spinal cord related to them.
Spinothalmic Pathway
An ascending somatic sensory pathway traveling from the spinal cord to the thalamus via the lateral spinothalamic columns; mediates information about pain, temperature, and some forms of touch.
Substantioa Gelatinosa
A thin dorsal part of the dorsal horn of the spinal cord that receives input from unmyelinated C fibers; important in the transmission of nociceptive signals.
