Term
| what are the 3 general theories of the cellular basis of aging? |
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Definition
| 1. wear and tear damage from internal and external sources; 2. damage from accumulation of internal byproducts of normal metabolism; 3. genetic predeterminatin of life=span of cell that exists within the cell nucleus |
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Term
| what are external sources that cause toxic damage of chromosomes or genes? |
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Definition
| irradiation, chemicals, infection |
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Term
| what are internal sources of wear and tear damage |
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Definition
| repeat usage that produces change in mechanical structure |
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Term
| how does the accuulatio nof internal byproducts of normal metabolism induce cellular aging |
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Definition
| as a result of metabolism, you have byproducts that escape degradative processes and accumulate. With accumulation, they produce damage. |
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Term
| what does the genetic predetermination of life-span of cells determine? |
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Definition
| the age that we will reach, and the way aging will manifest: pretty or not so prety? |
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Term
| what are current recommendations for long life |
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Definition
| nutritious and low cal diet, exercise, red wine in moderation, avoid stress, life partner, optimistic attitude, continued lifelong education, no smoking, old parents |
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Term
| what are the general effects of aging |
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Definition
| decrease in blood supply to tissues, decrease in number of reparative cells, less extensible tissues secondary to increased collagen fiber cross-links, decrease in metabolic activity of reparative cells |
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Term
| what is the result of decreased metabolic activity of reparative cells |
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Definition
| decreased capacity for healing, decreased inflammatory response, healing tissue is structurally weaker => need to be patient with these patients! |
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Term
| up to what age does tensile strength and density increase in bone |
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Definition
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Term
| how to promote tensile strength and densith in bone? |
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Definition
| good diet with dairy products, dark green leafy veggies, normal menses, limit caffeine |
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Term
| describe rates of bone change after age 30 |
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Definition
| increased rate of bone loss secondary to increased rate of bone resorption without increased rate of bone deposition |
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Term
| what are the results of bone resorption |
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Definition
| decreased bone densit, decreased number of trabeculae, decreased cortical and trabecular thickness |
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|
Term
|
Definition
| decreased mass of bone/volume, increased porosity |
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|
Term
| how does strength of bone change in aging |
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Definition
|
|
Term
| how does brittleness of bone change with aging |
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Definition
|
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Term
| how do osteocytes change with aging |
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Definition
| decreased cellular metabolic activity, decreased number |
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Term
| what is the result of decreased osteocytes |
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Definition
| decreased production of collagen/ground substance matrix |
|
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Term
| how does the percentage of mineral content to collagen in bone change with aging, and what are the results |
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Definition
| increase in mineral content percentage because of less collagen. This causes increased porosity with more calicum content, creating bone that is more brittle |
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Term
| how does decreased estrogen in postmenopausal women effect bone? |
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Definition
| decreased estrogen levels in women results in less inhibition of bone resorption |
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|
Term
| what determines the degree to which women have more bone loss than men? |
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Definition
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Term
| what is the bone loss of femoral neck for women compared to men |
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Definition
| women lose bone at a rate that is 150% the rate of loss for men. 2:1 ratio, therefore, for hip fractures. |
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Term
| what is the bone loss in the lumbar spine for women compared to men |
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Definition
| the rate is 4 times greater for older women than for older men. There is an 8:1 ratio for lumbar vertebral body fractures for older women compared to older men. |
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Term
| how to help older women reduce lumbar spine fractures |
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Definition
| stretch tight anterior soft tissues, add a little strength in the back extensors, and do postural training so they can achieve a more extended spine position |
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Term
| what is senile osteoporosis |
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Definition
| decreased bone mineral density that occurs with age in cortical and trabecular bone, primarily in women and to a lesser degree in men |
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|
Term
| what is postmenopausal osteoporosis |
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Definition
| excessive trabecular bone loss in women associated with decrease in estrogen levels and vertebral body fractures |
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Term
| how to prevent senile osteoporosis |
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Definition
|
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Term
| bone mineral density of what bones are maintained in older runners |
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Definition
|
|
Term
| how does Tai Chi affect BMD in the elderly? |
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Definition
| Tai Chi improves BMD AND decreases fall risk = big! |
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|
Term
| how does strength training affect bone density in older adults |
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Definition
|
|
Term
| what effect do steroids have on bone |
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Definition
| 25% of patients receiving long-term steroid treatment will develop an osteoporosis-related fracture |
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Term
| what to say to patients on long-term steroid treatment |
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Definition
| counsel prevention of osteoporosis and fall prevention through exercise, making sure things are asfe in the home, take a multivitamin, strengthen |
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Term
| what are the effects of excessive loading on bone in older adults |
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Definition
| excessive loading from abdominal flexion exercises and posture can cause fractures in the spine |
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Term
| how does articular cartilage change with aging |
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Definition
| increased water, decreased ground substance, decreased collagen density |
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Term
| what is the result of decreased ground substance and collagen density in aging articular cartilage |
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Definition
| increased permeability with loading. |
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|
Term
| what is the result of increased permeability of articular cartilage |
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Definition
| decreased time of loading, which increases the contact force. |
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|
Term
| what offsets the problem of increased permeability of aging articular cartilage? |
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Definition
| increased water helps maintain the time of deformation |
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|
Term
| what causes increased wear of articular cartilage with aging? |
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Definition
| increased stiffness of subchondral bone results in increased compressive stress on the articular cartilage AND proteoglycan loss decreases corss-links between collagen fibers |
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|
Term
| how to intervene to reduce effects of aging on articular cartilage? |
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Definition
| attenuate contact force and improve contact area to reduce contact pressure, do exercises that involve fluid film lubrication, repair ligamentous insufficiencies, modify/redirect activites that damage articular cartilage, moderate exercise, brace for instabilities with low level loads |
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|
Term
| how to attenuate contact force on articular cartilage? |
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Definition
|
|
Term
| how to improve contact area of articular cartilage |
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Definition
| address malalignments to increase contact area and reduce soft tissue forces |
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|
Term
| what to consider with bracing for articular cartilage effects of aging |
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Definition
| bracing is only effective for activites that involve low level loads transmitted across joints. They can't have forceful activities where the muscle tendon forces cause shearing across joints |
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|
Term
| how does exercise help articular cartilage? |
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Definition
|
|
Term
| describe the structure of intervertebral discs |
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Definition
| nucleus pulposus is surrounded by an annulus fibrosus and bordered superiorly and inferiorly by the cartilaginous vertebral endplates |
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|
Term
| what is the structure of the annulus fibrosu |
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Definition
| arranged in 10-12 sheets or lamellae: thick anteriorly and laterally but thin and packed tighter posteriorly, an area of structural weakness |
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|
Term
| what is the result of the posterolateral weakness in the annulus fibrosus |
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Definition
| at risk for bulging, lesions |
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|
Term
| what is the structural organization of the annulus fibrosus |
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Definition
| orientation of collagen fibers in each sheet is oblique, with alternating obliqueness in each sheet. |
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Term
| who do the collagen fibers alternate direction in each sheet of the annulus fibrosus? |
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Definition
| if they all went in the same direction, you'd only have strength in that one direction. This way, the entire structure with all he sheets together is much stronger in tensile stress |
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Term
| what part of the intervertebral disc disperses pressure so that you don't get focal areas of high pressure? |
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Definition
| fluid/water in the nucleus pulposus provides pressure dispersion to avoid focal areas of high prsesure |
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|
Term
| what would happen if you had focal areas of high pressure in the intervertebral disc |
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Definition
| the disc in that region would undego damage, and the vertebral body in line with that secion of the disc would also be damaged |
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|
Term
| what is the job of the nucleus pulposus of the intervertebral disc |
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Definition
| to even out the pressures that are transmitted so that they go across the entire disc and therefore across the entire vertebral body |
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|
Term
| when is dispersion of pressure especially important |
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Definition
| for off-center loading, such as on one side |
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|
Term
| what would happen if pressure was not distributed across all regions |
|
Definition
| compression fracture in vertebralbody |
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|
Term
| what is required for adequate dispersion of pressure in an intervertebral disc? |
|
Definition
| a lot of water in the disc |
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|
Term
| when the intervertebral disc is compresse,w hat happens |
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Definition
| compression raises pressure in the fluid filled nucleus pulposus. Pressure is then directed radially into the annulus, rasing tension in the annulus fibers |
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|
Term
| what happens when the annulus fibers feel tenson |
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Definition
| they provide a reaction force against the nucleu to resist further radial expansion of the radius and so that nuclera pressure is exerted evenly on the vertebral end plates |
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|
Term
| what happens once the vertebral end plates feel pressure from the nucleus pulposus? |
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Definition
| contact pressure is then distributed from the vertebral end plates to the next vertebral body |
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|
Term
| what are the structural changes in the nucleus pulposis with aging? |
|
Definition
| decreased proteoglycans, decreased water, decreased chondroitin sulfate, increased collagen, increased collagen-proteoglycan binding |
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|
Term
| what is the amount of decrease of proteoglycans in the nucleus pulposus by age 60? |
|
Definition
| decreased proteoglycans from 65% of dry weight to 30% of dry weight by age 60 |
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|
Term
| what is the result fo decreased proteoglycans |
|
Definition
| decreased strength of the tissue |
|
|
Term
| how much water is lost from the nucleus pulposus with aging |
|
Definition
| 6% decrease in water during adulthood |
|
|
Term
| what are the results of the decrease in water in nucleus pulposus? |
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Definition
| decrease in water makes tissue less able to distribute pressure throughout nucleus. You then see focal areas of pressure going through vertebral end plates and into vertebral body below |
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|
Term
| what does chondroitin sulfate do in the nucleus pulposus |
|
Definition
| binds water in the nucleus |
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|
Term
| what are the effects of loss of chondroitin sulfate in nucleus pulposus |
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Definition
| explains why we're losing water |
|
|
Term
| how does increased collagen-proteoglycan binding change the look of the nucleus pulposus |
|
Definition
| type II collagen of the nucleus takes on the appearance of Type I collagen of the annulus = the nucleus becomes more like the annulus |
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|
Term
| what is the annulus's job |
|
Definition
| to be a container for the nucleus |
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|
Term
| why is it bad when the nucleus pulposus has more collagen-proteoglycan bind that causes it to look more like the annulus? |
|
Definition
| we need the water filled-nucleus contents to distribute pressure, not act like a container. Without pressure distribution, we see focal areas of damage in the disc and in the vertebral body below' the stiffer nucleus is less able to recover from creep deformation |
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|
Term
| is there more or less distinction between annulus and nucleus with aging |
|
Definition
|
|
Term
| what are the effects of aging on the annulus fibrosus |
|
Definition
| decrease in diameter of collagen fibrils, loss of proteoglycans, decrease in elastin fibers, fibrillations in age that can form fissures |
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|
Term
| what is the result of the decrease in diameter of collagen fibrils of the annulus fibrosus |
|
Definition
| lost cross-sectional area of the individual fibers |
|
|
Term
| what is the result of the loss of proteoglycans in the annulus fibrosus |
|
Definition
| increase in percentage of collagen content, meaning the tissue is weaker |
|
|
Term
| how much loss of elastin fiber occurs in the annulus fibrosus from age 26 to 62 |
|
Definition
| 13% at age 26, 8% at age 62 |
|
|
Term
| what is the result in decreased elastin fiber content in the annulus fibrosus with age |
|
Definition
| the tissue is stiffer, less extensible = easier to damage |
|
|
Term
| what is the problem with fibrillations with age in the annulus fibrosus |
|
Definition
| they may enlarge into fissures that allow protrusion of nucleus material |
|
|
Term
| how does the size/shape of intervertebral discs change with age |
|
Definition
| discs enlarge in anterior-posterior diameter as well as height by 10% from age 20 to 70 as the vertebral body endplates fail and become concave |
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|
Term
| why do we get an overall loss in height despite this growth of the intervertebral discs? |
|
Definition
| there is more collapse/failure in vertebral end plates than increase in size of the disc |
|
|
Term
| how does smoking affect your risk for intervertebral disc injury? |
|
Definition
| increases your risk for prolapsed disc |
|
|
Term
| how does smoking affect your ability to recover from discectomy |
|
Definition
| makes it harder to repair and recover |
|
|
Term
| why is smoking so bad for intervertebral discs? |
|
Definition
| nicotine reduces the number of viable cells, reduces GAG and collagen syntehsis: bad for all reparative cells |
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|
Term
| what to consider for the aging spine to help out the intervertebral discs |
|
Definition
| not too much magnitude, duration, and frequency. Avoid smoking. Good posture to avoid focal concetration of loads |
|
|
Term
| why is it good to have good posture when you age |
|
Definition
| may help avoid focal concentration of loads in discs that are less able to distribute load throughout the disc and are less capable of withstanding focal loading of weaker annulus material |
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|
Term
| if you have kyphotic posture and you are an older adult, what problems are happening |
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Definition
| the nucleus has less water, the annulus is weaker. The pressure on the anterior portion of the disc from kyphotic posture is not dispersed well to the posterior portion, so there is increased compression on the anterior portion of vertebral bodies |
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|
Term
| what are the effects of aging on the meniscus |
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Definition
| fraying, increased proteoglycans, increased CPPD crystals, increased hydroxyapatite crystals, overall increased stiffness |
|
|
Term
| what contributes to increasd fraying of meniscal edges |
|
Definition
|
|
Term
| what is the rsult of increased CPPD and hydroxyapatite crystalsin the menisus |
|
Definition
| make the tissue stiffer, increases stress concetration between areas where the crystals are, increases chance of lesion |
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|
Term
| what is the effect of these component changes that cause the meniscus to be stiffer |
|
Definition
| it is less able to act as a shock absorber and distribute pressures over a larger area of articular cartilage; it is more likely to fail itself, and it is worse at protecting articular cartilage |
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|
Term
| what are the effects of aging on tendon? |
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Definition
| no great change in ultimate strength of tendon with aging until the 7th decade since thetendon is half dead to begin with |
|
|
Term
| what are the effects of aging on ligament |
|
Definition
| increased avulsion fracture risk because bone is getting weaker and ligament is still pretty strong since it doesn't change a lot with aging. |
|
|
Term
| what change really does happen with tendon and ligament with aging |
|
Definition
| increase in stiffness with aging secondary to an increase in cros-linkage binding between adjacent collagen fibers, therefore slightly weaker material that reaches greater levels of stress with accessory motions secondary to increased stiffness. |
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|
Term
| after age 20, what is the occurrence of loss of strength of tissues? |
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Definition
| skeletal muscle becomes weaker at 20, cartilage becomes weaker at 30, bone also gets weaker at 30 but doesn't fall as quickly as catilage, tendon gets weaker at 70 |
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|
Term
| what to consider with aging tendon/ligament interventios |
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Definition
| modulate magnitude, duration, and frequency of loads. Progressively increase these variables. Be patient withhealing |
|
|
Term
| why do you have to be patient with healing tendon and ligament |
|
Definition
| they have a lack of blood supply and they are metabolically sluggish |
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|
Term
| why is progressive increase in magnitude, duration, and frequency required for tendon and ligament |
|
Definition
| give the bone time to catch up: avoid avulsion fracture |
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|
Term
| are older people more at risk for chronic or acute musculoskeletal consitions |
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Definition
|
|
Term
| which type of muscle fiber atrophies faster |
|
Definition
|
|
Term
| which type of muscle fiber has a greater decrease in number of fibers |
|
Definition
|
|
Term
| describe type ii muscle fibers |
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Definition
| type II are the large motor units. The individual fibers are larger in cross section than Type I fibers. |
|
|
Term
| when do you use type ii muscle fiber |
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Definition
|
|
Term
| why is older muscle less able go generate large muscle force |
|
Definition
| less type ii muscle fibers |
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|
Term
| what is the lost muscle tissue replaced with? |
|
Definition
| fibrous connective tissue |
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|
Term
| what does the loss of type ii fibers + replacement of fibrous connective tissue add up to |
|
Definition
| loss of overall ability to produce peak tension, torque, and angular work = hard to cross the street in a hurry! |
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|
Term
| what is an operational definition of endurance |
|
Definition
| how long it takes to get a 50% decrement in torque (for example) |
|
|
Term
| how are operational definitions of endurance effected in older muscle |
|
Definition
| relatively unaffected; they produce less peak force, so it takes them just as long to get to the point of 50% peak force |
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|
Term
| what is a benefit of aging and muscles |
|
Definition
| decreased blood supply means less intense inflammatory response after injury, meaning less scar tissue |
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|
Term
| what are some downfalls of aging and muscle |
|
Definition
| fewer and less metabolically active satellite cells to help with healing, lower levels of strength attainable |
|
|
Term
| what are the implications for fewer and lessmetabolically active satellite cells |
|
Definition
| requires patience with healing and rehabilitation efforts |
|
|
Term
| what are the effects of aging on proprioception |
|
Definition
| loss of proprioceptoin: decreased ability to detect that your joints have moved, and decreased ability to replicate joint position |
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|
Term
| what are the effects of aging on simple and complex reaction time |
|
Definition
| both are increased, meaning a decreased ability to respond to internally or externally imposed perturbations during rehab or functional activities |
|
|
Term
| how do sweat rates change with aging |
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Definition
|
|
Term
| what is bad about decreased sweat rates |
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Definition
| you need to dissipate heat when you're exercising. Without sweat, you'll get greater bloodflow to the skin to try to dissipate heat through radiation. Thes means there is less bloodflow available for working muscles. And the working muscles are at a disadvantage already ebcause they're atrophied. so now the atrophied muscles don't have as much oxygen. and you're hot. |
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|
Term
| what lung changes occur with aging? |
|
Definition
| decreased lung functinal surface area for gas exchange: can't get oxygen in and CO2 out; increased airway resistance; decreased vital capacity |
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|
Term
| how does mean arterial pressure change with aging, and what does that mean |
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Definition
| increases: so you may have trouble controlling your blood pressure |
|
|
Term
| what are reasons why mean arterial pressure increases with aging |
|
Definition
| vessles are stiffening, less extensible AND there is stuff in the lumen of the blood vessels = atherosclerosis |
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|
Term
| how does cardiac stroke volume change with aging and what does this mean |
|
Definition
| decreased cardiac stroke volume: with each pumping fo the left ventricle, you aren't sending as much blood out. This adds up to decreased capacity to do work. Heat overload, inability to exchange gases as well, inability to deliver oxygen to the muscles. don't expect as much performance from older individuals |
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|
Term
| summarized cardiopulmonary reasons for reduced exercise capacity |
|
Definition
| less able to dissipate heat, reduced capacity to oxygenate blood, reduced capacity to deliver blood to working muscles, reduced blood supply to cardiac muscle |
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