chapter 4bb KNES

factors that mediate pain

1. narcotic-like, pain-killing compounds known as opioid peptides, including beta-endorphin and methionine enkephalin. Both work by blocking neural receptor sites that transmit pain. 2. The central nervous system also imposes a set of cognitive (i.e., quality of knowing or per- ceiving) and affective (i.e., pertaining to feelings or a mental state) filters on both the perception of pain and the subsequent expression of perceived pain 3. Social and cultural factors can be powerful influences on pain tolerance level. 63; slide 80

factors that mediate pain

Some brain cells have the ability to produce narcotic-like, pain-killing compounds known as opioid peptides, including beta-endorphin and methionine enkephalin. Both work by blocking neural receptor sites that transmit pain. Several different sites in the brain produce endorphins. Stressors, such as physical exercise, mental stress, and electrical stimulation, provoke the release of endorphins into the cerebrospinal fluid. A phenomenon called "runner's high," which is a feeling of euphoria that occurs among long distance runners, has been attributed to endorphin release. The brain stem and pituitary gland produce enkephalins. Enkephalins block pain neurotransmitters in the dorsal horn of the spinal cord. 63 brain production of opioid peptides and endorphins cognitive and affective filters slide 80

factors that mediate pain

The central nervous system also imposes a set of cognitive (i.e., quality of knowing or per- ceiving) and affective (i.e., pertaining to feelings or a mental state) filters on both the perception of pain and the subsequent expression of perceived pain. Social and cultural factors can be powerful influences on pain tolerance level. For example, in American society, it is much more acceptable for females than males to express feelings of pain. Individual personality and a state of mental preoccupation can also be significant modifiers of pain 63; cognitive effects and filters slide 79

pain

____________ can originate from somatic, visceral, and psychogenic sources

stress fracture

_____________, also known as FATIGUE FRACTURES, result form repeated low-magnitude forces; ______________ differ from acute fractures in that they can worsen over time, beginning as a small disruption in the continuity of the outer layers of cortical bone and ending as complete cortisal fracture with possible displacement of the bone ends; ______________ of the metatarsals, femoral neck, and pubis have been reported among runners who have apparently overtrained; stress fractures of the pars interarticularis region of the lumbar vertebrae occur in higher-than-normal frequencies among football linemen and female gymnasts 60 is an incomplete fracture fracture results from repeated loading with lower magnitude forces can become worse over time lumbar vertebrae is common site for stress fractures with AGING slide 65

avulsion fracture

______________ are another type of fracture caused by tensile loading that involve a tendon or ligament pulling a small chip of bone away form the rest of the bone; explosive throwing or jumping movements may result in ___________________ 60

closed fracture

______________ are considered to be ___________when the bone ends remain intact within the surrounding soft tissues and open or compound when one or both bone ends protrude form the skin

epiphyseal injury type 5

______________ involves compression of the epiphysis without fracture, resulting in compromised epiphyseal function 60

epiphyseal injury type 3

______________ involves fracture of the epiphysis

avulsion fracture

______________: bone fragment is pulled off by an attached tendon or ligament ________________: a bone fragment is pulled off by an attached tendon or ligament 59

epiphyseal injury type 2

_______________ involves separation of the epiphysis and a small portion of the metaphysis

epiphyseal injury type 4

_______________ involves: fracutre of a part of the epiphysis and the metaphysis 60

pain

_______________ is a negative sensory and emotional experience associated with actual or potential tissue damage; it is also a universal symptom common to most injuries; an individual's perception to pain is influenced by various physical, chemical, social, and psychological factors 62

impacted fracture

________________ bone is impacted or driven into another piece of bone _______________: bone is impacted, or driven into, another piece of bone 59

referred pain

________________ is perceived at a location remote from the site of the tissues actually causing the pain; a propsoed explanation for ___________________ begins with the fact that neurons carrying pain impulses split into several branches within the spinal cord; although some of these branches connect with other pain-transmitting fibers, some also connect with afferent nerve pathways from the skin; this cross-branching can cause the brain to misinterpret the true location of the pain; in some instances, _________________ behaves in a logical and predictable fashion; pain form the internal organs is typically projected outward to corresponding dermatomes of the skin; for example, heart attacks can produce a sensation of pain in the superior thoracic wall and the medial aspect of the left arm; in most cases, the affected internal organ and the corresponding dermatome receive innervation from the same spinal nerve roots 63 pain perceived at a location remote from the site actually causing the pain slide 80

spiral fracture

________________: Jagged bone ends are S-shaped when excessive torsion is applied to a fixed bone __________________: jagged bone ends are S-shaped because excessive torsion is applied to a fixed bone 59

simple , closed fracture

________________: bone breaks cleanly but ends do not break the skin _________________: the bone cleanly fractures, but the bone ends do not break the skin 59

comminuted fracture

________________: bone fragments into several pieces __________________: the bone fragments into several pieces 59

epiphyseal injury type 1

_________________ involves complete separation of the epiphysis from the metaphysis with no fracture of the bone 60

psychogenic pain

_________________ involves no apparent physical cause of the pain, although the sensation of pain is felt 62 slide 79

compressive injuries

_________________ of nerves are more complex because their severity depends on the magnitude and duration of loading and on whether the applied pressure is direct or indirect; because nerve function is highly dependent on oxygen produced by the associated blood vessels, damage to the blood supply caused by a _____________ results in damage to the nerve 62; slide 76

compound , open fracture

_________________: bone ends penetrate through soft tissue and skin ___________________: one or both of the bone ends penetrates through the soft tissues and the skin 59

oblique fracture

_________________: break occurs diagionally when torsion occurs on one end while the other is fixed ________________: the fracture occurs diagnoally when torsion occurs on one end while the other end is fixed 59

epiphyseal fracture

_________________: separation involves the epiphysis of the bone _________________: the separation involves the epiphysis of the bone 59

stress fracture

_________________: the fracture is incomplete, resulting from repeated low-magnitude forces that worsen over time 59

osteopnea

__________________ a condition of reduced bone mineral density, predisposes an individual to all types of fractures, but particularly to stress fractures; *the condition is primarily found among adolescent female athletes, especially distance runners, who are amenorrheic*; although amenorrhea among this group is not well understood, it appears to be related to a low percentage of body fat and/or high training mileage; the link between cessation of menses and osteopenea is also not well understood; possible contributing factors include *hyperactivity of osteoclasts, hypoactivity of osteoblasts, hormonal factors, and insufficiencies of dietary calcium or other minerals or nutrients* 60 reduced bone mineral density that predisposes individual to fracture possible causes: amenorrhea, hormonal factors, dietary insufficiencies slide 66

tensile or compressive injuries

__________________ most commonly include nerves; ____________ injuries are more likely to occur during severe high-speed accidents, such as automobile accidents or impact collisions in contact sports; when a nerve is loaded in tension, the nerve fibers tend to rupture prior to the rupturing of the surrounding connective tissue sheath; because the nerve roots on the spinal cord are not protected by connective tissue, they are particularly susceptible to tensile injury, especially in response to stretching of the brachial plexus or cervical nerve roots; nerve injuries caused by tensile forces are graded on three levels grade I is neuropraxia; grade II is axonotmesis, and grade III is neurotmesis 61

visceral pain

__________________, which is often diffuse or referred rather than localized to the problem site, originates form the internal organs 62 slide 79

transverse fracture

__________________: break occurs in a straight line across the bone _____________________: the fracture occurs on a straight line across the bone 59

depressed fracture

__________________: occurs more frequently on flat bones where the broken portion is driven inward ___________________: this fracture occurs more frequently on flat bones when the broken bone portion is driven inward 59

nerve injuries

____________________ can result in a range of afferent symptoms, from severe pain through complete loss of sensation; terms used to describe altered sesnsation includ ehypoesthesia, a reduction in sensation; hyperesthesia, heightened sensation; and paresthesia, a sense of numbness, prickling, or tingling; pinching of a nerve can result in a sharp wave of pain that is transmitted through a body segment; irritation or inflammation of a nerve can result in chronic pain along the nerve's course, known as neuralgia 62 _____________ result in a variety of symptoms: hyperesthesia- heightened sensation hypoestesia- diminished sensation paresthesia- nubmness, prickling, tingling neuralgia- chronnic pain along a nerve's course healing: if nerve is completely severed, healing does not occur slide 77

somatic pain

_______________________ originates in the skin as well as internal structures in the musculoskeletal system 62 slide 79

fracture

a _____________ is a disruption in the *continuity of a bone*; signs of ____________ include rapid swelling, ecchmyosis, deformity or shortening of the limb, precise point tenderness, graiting or crepitus, and guarding or disability; *the type of fracture sustained depends on the type of mechanical loading that caused it, as well as the health and maturity of the bone at the time of injury* 59 disruption in the continuity of bone; closed or open type of fracture determined by: force applied, the health and maturity of bone at the time of injury slide 63

gate control theory

according to the ________________, proposed by Melzack and Wall, the substantia gelatinosa acts as a gatekeeper by allowing either a pain response or one of the other afferent sensations to be transported by each T cell; the theory is substantiated by the observation that increased sensory input can reduce the sensation of pain; for example, extreme cold can often numb pain; because hundreds or thousands of gates are in operation, however, it is more common that added sensory input reduces rather than eliminates the feeling of pain because impulses get through to some of the T cells 62 fibers transmitting pain A fibers C fibers T CELLS gate control theory of pain slide 79

T cells

afferent nerves carrying pain impulses, along with those transporting sensations such as touch, temperature, and proprioception, articulate with the spinal cord through the substantia gelatinosa of the cord's dorsal horn; specialized _______________ then transmit impulses form all of the afferent fibers up the spinal cord to the brain, with each ____________ carrying a single impulse; within the brain, the pain impulses are transmitted to the thalamus, primarily its ventral posterior lateral nucleus, as well as to the somatosensory cortex, where pain is perceived 62 slide 79

osteochondrosis aka idiopathic osteochondrosis

another category of epiphseal injuries is _______________; ___________________ results from disruption of blood supply to an epiphysis with associated tissue necrosis and potential deformation of the epiphysis; because the cause of the condition is poorly understood, it is typically termed idiopathic ___________________ __________________ occurs more commonly between the ages of 3 and 10, and is more prevalent among boys than among girls; specific disease names have been given to sites where ______________ is common, such as Legg-Calve-Perthes disease, which is __________________ of the femoral head 61 disruption of blood supply to epiphysis idiopathic example: Legg-Calve-Perthes disease slide 68

torsional load

because bone is stronger in resisting compression than tension and shear, acute compression fractures of bone are rare; however, under combined loading a fracture resulting from a ______________ may be affected by the presence of a compressive load 59 tension, compression, shear, bending, torsion bones are stronger in resisting compression than both tension and shear slide 62

greenstick fractures

because bones of children contain relatively larger amounts of collagen than do adult bones, they are more flexible and more resistant to fracture under day to day loading than do adult bones; consequently, ______________-, or incomplete fractures, are more common in children than in adults; a _______________ is an incomplete fracture typically caused by bending or torsional loads 60

greenstick fracture

bone breaks incompletely, as a green stick breaks __________________: this fracture is incomplete (E.g. as a green stick breaks); this fracture is more common in children than in adults 59

spinal nerve

each ________________ is formed from anterior and posterior roots on the spinal cord that unite at the intervertebral foramen; the POSTERIOR BRANCHES are the AFFERENT (sensory) nerves that transmit information from sensory receptors in the skin, tendons, ligmanets, and muscles to the central nervous system; the ANTERIOR BRANCHES are the EFFERENT (motor) nerves that transmit control signals to the muscles; the nerve fibers are heavily vascularized and encased in a multilayered, segmental protective sheath called the MYELIN SHEATH; myelin protects and electrically insulates fibers from one another, and it increases the speed of transmission of nerve impulses; myelinated fibers (axons bearing a myelin sheath) conduct nerve impulses rapidly, whereas unmyelinated fibers tend to conduct impulses quite slowly 61 _______________: roots posterior- afferent anterior-efferent heavily vascularized myelin sheath slide 73

spiral fractures

excessive torsional and bending loads, as exemplified by tibial fractures resulting form skiing accidents, often produce _____________ of the long bones; such _____________ are the result of a combined loading pattern of shear and tesnion, producing failure at an oblique angle to the long axis of the bone 59

neurotmesis

grade 3 injuries represent _____________ injuries which disrupt the endoneruium; these severe injuries have a poor prognosis, with motor and sensory deficit persisting for up to 1 year; surgical intervention often is necessary to avoid poor or imperfect regeneration 62 grade 3 nerve injury motor and sensory deficit lasts up to 1 year slide 75

neuropraxia

grade I; nerve injuries caused by tensile forces are graded on three levels; grade I injuries represent _______________, the mildest lesion; a _______________ is a localized conduction block that causes temporary loss of sensation and/or motor function form selective demyelination of the axion sheath without true axonal disruption; recovery usually occurs within days to a few weeks 61 tensile force injury ______________ grade I localized conduction block: temporary loss of sensation and/or motor resolves within days to few weeks slide 74

axonotmesis

grade II injuries are called ________________ injuries that produce significant motor and mild sensory deficits that last at least 2 weeks; _______________ disrupts the axon and myelin sheath but leaves the epinerium intact; the epineurium is the connective tissue that encapsulates the nerve trunk and binds the fascicles together; axonal regrowth occurs at a rate of 1-2 mm per days; full or normal function is usually restored 61 grade 2 significant motor and mild sensory defecits lasts at least 2 weeks slide 74

nociceptors

in most acute injuries, pain is initiated by mechanosensitive ______________ responding to the traumatic force that caused the injury; in chronic injuries and during the early stages of healing of acute injuries, pain persists because of activation of chemosensitive _________________; Bradykinin, serotonin, histamines, and prostaglandins are all chemicals transported to the injury site causing inflammation that activate the chemosensitive ____________; thermal extremes can also stimulate other specialized _____________ to produce pain 62 ________________: mechanosensitive chemosensitive slide 79

nerve injuries

management of __________________: mild: follow acute care protocol moderate-to-severe: physician referral slide 78

radiating pain

referred pain should not be confused with ______________, which is pain that is felt both at its source and along a nerve; pinching of the sciatic nerve at its root may cause pain that radiates along the nerve's course down the posterior aspect of the leg 63 pain felt both at its source and along a nerve slide 80

nociceptors

stimulation of specialized afferent nerve endings called ________________ *produces the pain sensation*; ______________ are prevalent in the skin, meninges, periosteum, teeth, and some internal organs 62 slide 79

mechanical forces affecting bones

tension, compression, shear, bending, torsion bones are stronger in resisting compression than both tension and shear slide 62

nervous system

the _____________ is divided into the central nervous system, consisting of hte brain and the spinal cord, and the peripheral nervous system, which includes 12 pairs of cranial nerves and 31 pairs of spinal nerves, along with their branches; there are 8 pairs of cervical spinal nerves, 12 pairs of thoracic nerves, 5 pairs of lumbar nerves, 5 pairs of sacral nerves, and 1 pair of coccygeal nerves; injuries to any of these nerves can be devastating to the individual, potentilaly resulting in temporary or permanent disability 61

Apophysitis

the apophyses are also subject to osteochondrosis, particulalry among children and adolescents; these conditions, referred to as _______________________, may be idopathic; however, they can be associated with traumatic avulsion-type fractures; common sites for ______________ are the calcaneus (i.e. sever's disease) and the tibial tubercle at the site of the patellar tendon attachment (i.e. Osgood-Schlatter's disease) 61 osteochondorsis of aphphysis example sever disease- inflammation of growth plate in heel osgood-schlatter disease slide 68

torsion

the application of a rotational force about hte long axis of a structure, such as a long bone, can cause ____________, or twisting of the structure; __________________ results in the creation of shear stress throughout the structure; skiier with foot planted rotates during a fall creating torsional load that can cause spiral fracture 59

epiphyseal injuries

the bones of children and adolescents are vulnerable to __________________, including injuries to the cartilaginous epiphyseal plate, articular cartilage, and apophysis; the apophyses are sites of tendon attachment to bone, where bone shape is influenced by the tensile loads to which these sites are subjected; *both acute and repetitive loading can injure the growth plate, potentially resulting in premature closure of the epiphyseal junction and termination of bone growth* e.g. Little League elbow, a stress injury to the medial epicondylar epiphysis of the humerus 60

bending and torsion

the type of fracture sustained depends on the type of mechanical loading that caused it, as well as the health and maturity of the bone at the time of injury; in addition to *compression, tension, and shearing mechanisms, bone is susceptible to ________________ and ____________ forces*; the simultaneous application of forces form opposite directions at different points along a structure, such as a long bone can cause ________________ and ultimately fracture of the bone; e.g. football player tackled from two directions, bend bone, loading one side of bone with tension and causing fracture 59

afferent nerves

two types A and C fibers of ______________ transmit the sensation of pain to the spinal cord; small-diameter slow-transmission, unmyelinated C fibers transmit low-level pain that might be described as dull or aching; larger, faster, thinly myelinated A fibers transmit sharp, piercing types of pain; pain can be transmitted along both types of ________________ from somatic and visceral sources; actively involving A and C fibers from the visceral organs can also provoke autonmic responses, such as changes in blood pressure, heart rate, and respiration 62 slide 79

comminuted fracture

when loading is very rapid, a fracture is more likely to be _____________, meaning it contains multiple fragments 60