Anatomy and Physiology: Chapter 13 - PNS Flashcards
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| 5328200255 | Peripheral nervous system (PNS) | Portion of the nervous system consisting of nerve, ganglia, sensory receptors, and motor endings that lie outside the brain and spinal chord | 0 | |
| 5328200256 | Sensory (afferent) nerves | Nerves that contain processes of sensory neurons and carry impulses to the CNS | 1 | |
| 5328200257 | Sensory receptors | A cell or part of a cell specialized to respond to a stimulus | 2 | |
| 5328200258 | Stimulus | An excitant; a change in the environment that evokes a response | 3 | |
| 5328200259 | Sensation | Awareness of the stimulus | 4 | |
| 5328200260 | Perception | Interpretation of the meaning of the stimulus | 5 | |
| 5328200261 | Mechanoreceptors | Respond to mechanical force such as touch, pressure (including blood pressure), vibration, and stretch | 6 | |
| 5328200262 | Thermoreceptors | Respond to temperature changes | 7 | |
| 5328200263 | Photoreceptors | Such as those of the retina of the eye, respond to light | 8 | |
| 5328200264 | Chemoreceptors | Respond to chemicals in solutions (molecules smelled or tasted, or changes in blood or interstitial fluid chemistry) | 9 | |
| 5328200265 | Nociceptors | (Noci = harm) Respond to potentially damaging stimuli that result in pain ex: searing heat, extreme cold, excessive pressure, and inflammatory chemicals are all interpreted as painful; these signals stimulate subtypes of thermoreceptors, mechanoreceptors, and chemoreceptors | 10 | |
| 5328200266 | Exteroceptors | Are sensitive to stimuli arising outside the body (extra = outside); they are near or at the body surface; includes touch, pressure, pain, and temperature receptors in the skin and most receptors of the special senses (vision, hearing, equilibrium, smell, and taste) | 11 | |
| 5328200267 | Interoceptors | Also called visceroceptors, respond to stimuli within the body (intro = inside), such as from the internal viscera and blood vessels; monitor a variety of stimuli includes chemical changes, tissue stretch and temperature; their activity causes us to feel pain, discomfort, hunger, or thirst; unaware of the workings | 12 | |
| 5328200268 | Proprioceptors | Occur in skeletal muscles, tendons, ligaments, joints, and in connective tissue covering the bones and muscles; advises the brain of our body movement (propria = one's own) by monitoring how much the organs containing these receptors are stretched | 13 | |
| 5328200269 | Special sense | Vision, hearing, equilibrium, smell, and taste | 14 | |
| 5328200270 | Nonencapsulated (free) nerve endings | Particularly abundant in epithelial and connective tissue; most sensory nerve fibers are non-myelinated, c-fibers, and their distal endings usually have small knob-like swellings; respond chiefly to temperature changes and painful stimuli, some respond to muscle movement and pressure (tactile and hair follicle) | 15 | |
| 5328200271 | Tactile (Merkel) discs | Lie deepest in the dermal layer of the epidermis, function as light touch receptors; exteroceptors and mechanoreceptors, slowly adapting |  | 16 |
| 5328200272 | Hair follicle receptors | Free nerve ending that wrap basket-like around hair follicles, are light touch receptors that detect bending of hairs; exteroceptors and mechanoreceptors, rapidly adapting |  | 17 |
| 5328200273 | Encapsulating nerve endings | Consists of one or more nerve fiber terminals of sensory neurons enclosed in a connective tissue capsule; virtually all mechanoreceptors | 18 | |
| 5328200274 | Tactile (Meissner's) corpuscles | Small receptors in which a few spiraling sensory terminals are surrounded by Schwann cells and then by a thin leg-shaped connective tissue capsule; found beneath the epidermis in the dermal papillae, numerous in hairless skin areas (nipples, fingertips, and soles of the feet); exteroceptors and mechanoreceptors, rapidly adapting |  | 19 |
| 5328200275 | Lamellar (Pacinian) corpuscles | Scattered in the deep in the dermis and the subcutaneous tissue underlying the skin; larges corpuscle receptors, single dendrite surrounded by a capsule of collagen fibers; exteroceptors, interoceptors, and proprioceptors; mechanoreceptors, are rapidly adapting |  | 20 |
| 5328200276 | Bulbous corpuscles (Ruffini endings) | Lie in the dermis, subcutaneous tissue, and joint capsules; contain a spray of endings enclosed by a flattened capsule exteroceptors and proprioceptor; mechanoreceptors, slowly or non-adapting |  | 21 |
| 5328200277 | Muscle spindles | Spindle-shaped proprioceptors founding the skeletal muscles (particularly extremities); muscle spindles detect muscle stretch and initiate a reflex that resists the stretch; proprioceptors and mechanoreceptors |  | 22 |
| 5328200278 | Tendon organs | Are proprioceptors located in the tendons, close to the junction between the skeletal muscle and the tendon; small bundles of a tendon enclosed in a layered capsule; proprioceptors and mechanoreceptors | 23 | |
| 5328200279 | Joint kinesthetic receptors | Monitor stretch in the articular capsules that enclosed synovial joint; proprioceptors and mechanoreceptors | 24 | |
| 5328200280 | Somatosensory system | The part of sensory system dealing with reception in the body wall and limbs; receives input from from exteroceptors, proprioceptors, and interoceptors | 25 | |
| 5328200281 | Receptor level | Sensory reception and trasmission to CNS | 26 | |
| 5328200282 | Transduction | The conversion of the energy of a stimulus into an electrical event (graded potential) | 27 | |
| 5328200283 | Generator potenital | The graded potential generates action potential in a sensory neuron | 28 | |
| 5328200284 | Receptor potential | A graded potential that occurs at a sensory receptor membrane | 29 | |
| 5328200285 | Adaptation | (1) A change in any in structure or response to suit a new environment; (2) decline in the transmission of a sensory nerve when a receptor is stimulated continuously and at a constant stimulus strength | 30 | |
| 5328200286 | Phasic receptors | Fast adapting, often giving bursts of impulses at the beginning and at the end of the stimulus; report changes in the internal or external environment (lamellar and tactile corpuscles) | 31 | |
| 5328200287 | Tonic receptors | Provide a sustained response with little or no adaptation; includes nociceptors and most proprioceptors because of the protective importance of their information | 32 | |
| 5328200288 | Circuit level | Processing in ascending pathways; delivers impulses to the appropriate region of the cerebral cortex for localization and perception of stimulus | 33 | |
| 5328200289 | Perceptual level | Processing in cortical sensory centers; sensory input is interpreted in the cerebral cortex | 34 | |
| 5328200290 | Projection | Eletrically stimulating a particular spot in the visual cortex causes you to "see" light in a particular space | 35 | |
| 5328200291 | Perceptual deception | The ability to detect that a stimulus has occurred; the simplest level of perception; inputs from several receptors must be summed for perpetual detection to occur | 36 | |
| 5328200292 | Magnitude estimation | The ability to detect how intense the stimulus is; perceived intensity increases because as stimulus intensity increases because of frequency coding | 37 | |
| 5328200293 | Spatial discrimination | Allows us to identify the cite or pattern of stimulation | 38 | |
| 5328200294 | Two-point discrimination | A test to study how close together 2 points on the skin can be and still be perceived as 2 points rather than 1 | 39 | |
| 5328200295 | Feature abstraction | Is the mechanism by which a neuron or circuit is tuned to one feature, or property, of a stimulus in preference to others; enables us to identify more complex aspects of a sensation | 40 | |
| 5328200296 | Quality discrimination | Is the ability to differentiate the submodalities of a particular sensation; each sensory modality has several qualities | 41 | |
| 5328200297 | Pattern recognition | The ability to take in the scene around us and recognize a familiar pattern an un familiar one, or one that has special significance for us | 42 | |
| 5328200298 | Hyperalgesia | Greater than normal sensitivity to pain | 43 | |
| 5328200299 | Referred pain | Which pain stimuli arising from one part of the body are perceived as coming from another part | 44 | |
| 5328200300 | Nerve | A chord like organ that is part of the peripheral e=nervous system | 45 | |
| 5328200301 | Endoneurium | A delicate layers of loose connective tissue that also enclose the fiber's associated Schwann cells | 46 | |
| 5328200302 | Perineurium | Coarser connective tissue wrapping binds a group of fascicles | 47 | |
| 5328200303 | Fascicles | Bundles of axons | 48 | |
| 5328200304 | Epineurium | Closes the fascicles to form the nerve | 49 | |
| 5328200305 | Mixed nerves | Contain both sensory and motor fibers and transmit impulses both to and from the CNS | 50 | |
| 5328200306 | Motor (efferent) nerves | Carry impulses only away from the CNS | 51 | |
| 5328200307 | Ganglia | Collections of neuron cell bodies associated with nerves of the PNS | 52 | |
| 5328200308 | CNS axons | These axons never regenerate from injury, damage to the brain or spinal chord are viewed irreversible; oligodendrocytes actively suppress axon regeneration, astrocytes block the growth of a new axon with scar tissue | 53 | |
| 5328200309 | PNS axons | Can regenerate successfully if they are crushed or cut; macrophages clean out the dead axons distal to the injury, axon filaments grow through a regeneration tube, and myelin sheath forms | 54 | |
| 5328200310 | Cranial nerves | The 12 nerve pairs that are associated to the brain | 55 | |
| 5328200311 | Olfactory | (I) The tiny sensory nerves (filaments) of smell which run from the nasal mucosa to synapse with olfactory bulbs; Sensory | 56 | |
| 5328200312 | Optic | (II) Fibers arise from retina of the eye, passes through optic canal of orbit, vision;sensory | 57 | |
| 5328200313 | Oculomotor | (III) Fibers extend from ventral midbrain (near its junction with the pons) and pass through bony orbit; motor; "eye mover" | 58 | |
| 5328200314 | Trochlear | (IV) Fibers emerge from the dorsal midbrain and coarse ventrally around midbrain to enter orbit through superior orbital fissure; motor; "pulley" | 59 | |
| 5328200315 | Trigeminal | (V) Largest cranial nerves, fibers extend from pons to face and from 3 divisions: ophthalmic, maxillary, and mandibular; sensory | 60 | |
| 5328200316 | Abducens | (VI) This nerve controls the extrinsic eye muscle that abuts the eye and turns it laterally; motor | 61 | |
| 5328200317 | Facial nerves | (VII) A large never that innervates muscles of facial expressions; both (taste) | 62 | |
| 5328200318 | Vestibulocochlear | (VIII) Both sensory and motor (hearing); this nerve is found in the inner ear | 63 | |
| 5328200319 | Glossopharyngeal | (IX) Means tongue and pharynx; both (taste) | 64 | |
| 5328200320 | Vagus | (X) Wander or vagabond, its the only cranial nerve to extend beyond the head and neck to the thorax and the abdomen | 65 | |
| 5328200321 | Accessory | (XI) Considered and accessory pat of the vagus nerve, they from the rootlets that emerge from the spinal chord, not the brain stem; both | 66 | |
| 5328200322 | Hypoglossal | (XII) Meaner under the tongue and it runs inferior to the tongue and innervates the tongue muscles; roots from the medulla and exits the skull; both allow tongue movements | 67 | |
| 5328200323 | Rootlets | Attach along the length of the corresponding spinal chord segment | 68 | |
| 5328200324 | Ventral root | Contain motor (efferent) fibers that arise from ventral horn motor neurons and extend to an and innervate the skeletal muscles | 69 | |
| 5328200325 | Dorsal root | Contain sensory (afferent) fibers that arise from sensory neurons in the dorsal root ganglia and conduct impulses from peripheral receptors to the spinal chord | 70 | |
| 5328200326 | Ramus | Branch | 71 | |
| 5328200327 | Nerve plexus | Interlacing nerve networks that occur in the cervical, brachial, lumbar, and sacral regions and primarily serve the limbs | 72 | |
| 5328200328 | Cervical plexus | C1 - C5 |  | 73 |
| 5328200329 | Upper limb plexus | C4 - T1 |  | 74 |
| 5328200330 | Lumbar plexus | L1 - L5 |  | 75 |
| 5328200331 | Sacral plexus | L4 - Co1 |  | 76 |
| 5328200332 | Dermatome | An area of skin innervated by the cutaneous branches of a single spinal nerve | 77 | |
| 5328200333 | Hilton's law | Any nerve serving a muscle that produces movement at a joint also innervates a joint and the skin over the joint | 78 | |
| 5328200334 | Motor endings | The PNS elements that activate effectors by releasing neurotransmitters | 79 | |
| 5328200335 | Segmental level | Lowest level of the motor hierarchy, it consists of reflexes and spinal chord circuits that control automatic movements; contains central pattern generations (CPG) | 80 | |
| 5328200336 | Central pattern generations | Circuits that control locomotion and other specific oftrepated motor activities; consists of networks of oscillating inhibitory and excitatory neurons, which set crude rhythms and alternating patterns of movement | 81 | |
| 5328200337 | Projection level | Consists of neurons actin through the direct and indirect motor pathway; middle level of the motor hierarchy; conveys instructions to the spinal chord motor neurons and sends a copy of that information to higher levels | 82 | |
| 5328200338 | Precommand level | Highest level of the motor hierarchy; located in the brain stem and the cerebellum; it regulates motor activity, precisely start or stop movements, coordinate movements with posture, block unwanted movements, and monitor muscle tone | 83 | |
| 5328200339 | Reflex arc 5 components | 1. Receptor 2. Sensory input 3. Integration center 4. Motor neuron 5. effector | 84 | |
| 5328200340 | Receptor | Site of stimulus action | 85 | |
| 5328200341 | Sensory neuron | Transmits afferent impulses to the CNS | 86 | |
| 5328200342 | Integration center | May be a single synapse between a sensory neuron and a motor neuron (monosynaptic); more complex reflex arcs involve multiple synapses with chains of interneurons (polysynaptic) | 87 | |
| 5328200343 | Motor neuron | Conducts efferent impulses from the integration center to the effector organ | 88 | |
| 5328200344 | Effector | Muscle fiber or gland cell that responds to the efferent impulses (by contracting or secreting) | 89 |