Ch. 12: Musculoskeletal Function Flashcards
type of bone that has bodies longer than they are wide, growth plates at either end, hard outer surface, and inner regions that are less dense than the outer regions and contain bone marrow
long bones
what are the ends of long bones covered in? why?
hyaline cartilage to help protect the bone by reducing friction and absorbing shock
bones that are approximately as wide as they are long. primary function is providing support and stability with little movement and contain relatively large amounts of bone marrow
short bones
bones that are strong, level plates of bone that provide protection to the body’s organs and a base for muscular contraction
flat bones
in adults, where are most red blood cells formed?
in flat bones
bones that don’t fall into any other category and primarily consist of spongy bone with a thin outer layer of compact bone
irregular bone
bones that are usually short or irregular bones embedded in a tendon. often present in a tendon where it passes over a joint and serve to protect tendon
sesamoid bones
layer of connective tissue that covers compact bone surfaces and serves the site of muscle attachment
periosteum
cells that aid in remodeling and repair of bone
osteoblasts
which type of bone marrow is mainly in the bones of infants and childrens?
red bone marrow
why do adults have more yellow bone marrow?
red bone marrow is slowly replaced by fat as the human ages. yellow bone marrow begins to form at adolescence and is present in most bones by adulthood
can the yellow blood marrow be reactivated to produce red blood cells?
yes, under certain circumstances
break down bone
osteoclasts
osteocyte
when osteoblasts become surrounded by calcified extracellular material, the complex is referred to as an osteocyte
many osteocytes organized into thin layers
lamellae
bone needs a balance between what two things for optimal bone function?
mineral components and collagen
how does growth hormone increase the rate of bone growth?
by causing cartilage and bone cells to reproduce and lay down their intercellular matrix as well as by stimulating materialization within the matrix
how does bone grow in appositional growth?
new bone forms on the surface of a bone
how does bone grow in endochondral growth
bone eventually replaces new cartilage growth in the epiphyseal plate
how does vitamin D play a role in bone metabolism?
it controls the absorption of calcium from the intestines and increases calcium and potassium reabsorption from the kidneys
what type of cartilage is most closely associated with bones and commonly found in joints?
hyaline cartilage
the most common type of joint. freely moveable
synovial joint
what is synovial fluid secreted by? what is the purpose of it?
secreted by the synovial membrane in order to reduce friction. it also contains leukocytes to fight infections in the joints and provides nutrients to the cartilage
structure that joins one bone to another
joint capsule
connect bones to bones in a joint and provide support to the joint
ligaments
slightly moveable joints, like those in the vertebral column
amphiarthroses
immoveable joints, like those in the skull
synarthroses
how are synarthrotic joints held together?
fibrous connective tissue extends the space between the interlocking bones, holding them together
muscle that connects to bone and is the most frequent type. under voluntary control.
skeletal muscles
line the walls of hollow organs and tubes and are found in the eyes, skin, and glands. involuntary
smooth muscle
makes up the heart and is under involuntary control
cardiac muscle
connects muscle to bone
tendons
what do muscles that steady joints assist with?
posture
do muscle fibers have single nuclei or multiple?
multiple
threadlike structures that extend the entire length of the muscle fiber?
myofibrils
involved in muscular contraction, cellular movement, and cell shape maintenance
actin myofilaments
fibrous globulins that work with actin to form actomyosin
myosin myofilaments
gives muscle its striated appearance
the alignment of the myofilaments
how do muscle fibers contract?
by sliding actin filaments over myosin filaments. in this process the myosin filaments pull the actin filament
each muscle fiber is enclosed by a cell membrane called
the sarcolemma
what does increases in muscle size reflect?
increases in individual muscle fibers. this increase in muscle size and strength results from an increase in the amount of contractile protein inside the muscle fiber
what do congenital musculoskeletal disorders usually affect?
primarily affect posture
increase in curvature of the thoracic spine outward
kyphosis
when does kyphosis usually appear
in the adolescent growth spurts and can appear as poor posture. in adults, kyphosis usually develops secondary to osteoporosis, degenerative spine disease, or injury.
what can severe kyphosis impair?
lung expansion and ventilation
why are patients with kyphosis at increased risk of injury?
because their center of gravity is altered
what are some other manifestations of kyphosis?
fatigue, back pain, and spine stiffness
an exaggerated concave of the lumbar spine
lordosis
when does lordosis develop?
may develop during adolescent growth spurts or because of poor posture
what can increase the tendency of lordosis?
obesity because it can cause an altered center of gravity and postural compensation.
what is lordosis commonly associated with?
dwarfism
lateral deviation of the spine
scoliosis
what are some congenital musculoskeletal disorders?
kyphosis, scoliosis, lordosis
the lateral curvature of the spine may affect what two areas of the spine?
may affect the thoracic or lumbar area, or both. may also cause a rotation of the vertebrae on their axes
why does the curvature of scoliosis increase during growth spurts?
because stress on the vertebrae causes an imbalance in osteoclast activity
who is scoliosis most common in?
females
what may be some causes of scoliosis?
most cases are idiopathic, but may also be caused by genetic influences, embryonic developmental deformities, degenerative diseases, unequal leg lenghts, spinal nerve compression, and asymmetrical muscle support
what are some complications of scoliosis?
pulmonary compromise, chronic pain, degenerative arthritis of the spine, intervertebral disk disease, and sciatica
what do the clinical manifestations of scoliosis depend on?
the curvature of the spine and are exaggerated when the person bends over
what are the clinical manifestations of scoliosis?
asymmetrical hip and shoulder alignment, asymmetrical thoracic cage, asymmetrical gait, back pain or discomfort, fatigue, indications of respiratory compromise
are traumatic muscular disorders serious?
no they are usually mild and easily treated. they may be life threatening if some complications occur
what may occur with the musculoskeletal injury?
neurological dysfunction
break in the rigid structure of the bone
fracture
most common type of traumatic musculoskeletal disorders
fractures
how can fractures occur?
due to trauma or secondary to conditions that weaken the bone
what are fractures classified on?
characteristics such as the direction of the fracture, number of fracture lines, or other characteristics
what are the types of simple fracture?
transverse, oblique, and spiral
fracture with a single break in the bone and in which the bone ends maintain their alignment and position
simple fracture
a fracture straight across the bone shaft
transverse fracture
a fracture at an angle to the bone shaft
oblique fracture
a fracture that twists around the bone shaft
oblique fracture
fracture characterized by multiple fracture lines and bone pieces
comminuted fracture
incomplete fracture in which the bone is bent and only the outer curve of the bend is broken; commonly occurs in children because of minimal calcification and often heals quickly
greenstick fracture
fracture in which the bone is crushed or collapses into small pieces
compression fracture
when the bone is broken into two or more separate pieces
complete fractures
when the bone is partially broken
incomplete fracture
when the skin is broken with a fracture
open, or compound, fracture
fracture in which the skin is intact
closed fracture
when one end of the bone is forced into the adjacent bone
impacted fractures
fractures that result from a weakness in the bone structure secondary to conditions such as bone tremors or osteoporosis
pathologic fractures
fractures that occur from repeated or excessive stress
stress fractures
occur in the skull when the broken piece is forced inward on the brain
depressed fracture
what happens when a bone breaks?
blood from the damaged blood vessels in the periosteum and bone marrow pours into the fracture and forms a hematoma, or blood clot. necrosis occurs to the broken ends of the bone because of the vessel damage, this necrotic tissue is reabsorbed and eventually replaced by new bones. within a few days, fibroblasts invate the clot and secrete collagen fibers which form a mass of cells and fibers called a callus which bridges the broken ends together inside and out. after a while osteoblasts slowly convert the callus to bone
what are some complications that can occur because of a fracture?
delayed union, malunion, or nonunion. compartment syndrome, fat embolism, osteomyelitis, and osteonecrosis
results from pressure increases in a compartment, usually the muscle fascia in the case of fractures. the pressure impinges on the nerves and blood vessels within the compartment, potentially compromising the distal extremity.
compartment syndrome
what are the clinical manifestations of compartment syndrome?
excruciating pain beyond what would be expected given the injury
occurs when fat has the opportunity to enter the bloodstream after a fracture to one of the long bones. the emboli can travel to other vital organs such as the lungs, heart, or brain which can be fatal.
fat embolism
how can a fat embolism be prevented?
through early immobilization of the joint
an infection of bone tissue that often goes undetected and can take months to resule and can result in tissue or bone necrosis
osteomyelitis
avascular necrosis. the death of bone tissue due to a loss of blood supply. can result from displaced fractures or dislocation
osteonecrosis
what are the clinical manifestations of fractures?
deformity, swelling at the site, inability to move the affected limb, crepitus, pain, paresthesia, muscle flaccidity progressing to spasm
separation of two bones where they meet at a joint
dislocation
how does dislocation affect the joint?
causes deformity and immobility of the joints and may damage nearby ligaments and nerves
what does dislocation usually result from?
injury to a joint. usually from a sudden impact, but they may also be congenital or pathologic
where are dislocations common?
in the shoulder and clavicle joints
what are the clinical manifestations of a dislocation?
visibly out-of-place, discolored, or deformed joint, limited movement, swelling or bruising, intense pain especially with movement or weight bearing, paresthesia near the injury
injury to a ligament that often involves stretching or tearing of the alignment caused by a joint being forced into an unnatural position
sprain
what sprains occur most often?
ankle and knee sprains
why does a sprained joint swell?
the injury triggers the inflammatory process, resulting in edema and pain at the site
why does a sprained joint bruise?
blood vessels may be damaged, resulting in bleeding and bruising. this bleeding in the joint capsule can delay healing
what happens if the sprained joint has a tear?
granulation tissue develops along with the inflammation. collagen fibers form to create a link between the torn ligament fragments and eventually fibrous tissue binds them together.
what are the clinical manifestations of a sprain?
joint stiffness, limited function, disability, and discoloration
injury to a muscle or tendon that often involves stretching or tearing of the muscle or tendon
strain
does a strain develop suddenly?
it can develop suddenly or over time
what does a strain result from?
an awkward muscle movement or excess force that can be caused by an accident, improper use of a muscle or overuse of a muscle
what is the most common site for strains
the lower back
what are the clinical manifestations of strains?
pain, stiffness, difficulty moving the affected muscle, skin discoloration, and edema
state in which the nucleus pulosus (the inner gelatinous component of the intervetebral disk) protrudes through the annulus fibrosus (the tough outer covering of the disk) may also be called a slipped disk
herniated intervetebral disk
does a herniated intervertebral disk occur suddenly?
it can occur suddenly or gradually
what problems can a herniated intervertebral disk cause?
it can cause orthopedic problems or neurologic problems because protrusions into the extradural space can exert pressure on the spinal cord, interfering with nerve conduction. sensory, motor, or autonomic function may be impaired depending on the location
what is the most common region for a herniated intervertebral disk?
the lumbosacral region
what is the usual cause of a herniated intervertebral disk?
often occurs due to improper body mechanics, lifting heavy duty objects, or trauma. additional contributing factors include degenerative changes secondary to aging and demineralization secondary to metabolic condtions
what are the clinical manifestations of a herniated intervertebral disk?
may be asymptomatic. when present: sciatica; pain, paresthesia, or weakness in the lower back and one leg, or in the neck, shoulder, chest, or arm; low back pain or leg pain that is worse when sitting, coughing, sneezing, laughing, or bending; limited mobility
what are the types of traumatic musculoskeletal disorders?
fractures, dislocation, sprains, strains, herniated intervertebral disk
what are the types of metabolic bone disorders?
osteoporosis, rickets and osteomalacia, Paget’s diseas
what are metabolic bone disorders?
variety of bone conditions caused by mineral abnormalities that can be caused by genetic factors or dietary deficits
condition characterized by progressive loss of bone calcium that leaves the bone brittle.
osteoprosis
what can the loss of bone mass of osteoporosis occur due to?
due to either a decrease in osteoblast activity or an increase in osteoclast activity
what occurs during osteoporosis?
the spongy bone becomes porous, particularly in the vertebrae and wrist, and the compact bone becomes thin
is osteoporosis a primary or secondary condition?
it can be either
what are risk factors for the development of osteoporosis?
genetic, dietary, and hormonal influences. calcium deficiency, deficient intake of protein, vitamin C and vitamin D as well as excessive intake of phosphorus. caucasians and asians. smoking, excessive alcohol intake or caffeine consumption, use of certain medications, specific health conditions, and being underweight
what does osteoporosis lead to?
increased risk for fractures
what are the clinical manifestations of osteoporosis?
often asymptomatic in early stages, fracture may be the first indicator. osteopenia, bone pain or tenderness, fractures with little or no trauma, low back and neck pain, kyphosis, height reduction over time
softening and weakening of the bones in children, usually because of an extreme and prolonged vitamin D, calcium, or phosphate deficiency
rickets
rickets in adults
osteomalacia
what happens if the blood levels of minerals become too low?
the minerals are released out of the bones to maintain homeostasis and this causes the bones to become weak and soft
why may a person develop rickets or osteomalacia?
they may have a lack of vitamin D production by the skin, lactose intolerance may cause a dietary deficiency, infants who are only breastfed because breast milk does not contain the proper amount of vitamin D, conditions that reduce the digestion or absorption of fats, insufficient dietary calcium and phosphorus intake (rare in developed countries), genetic influences that cause the kidneys to be unable to reabsorb phosphate, children who have liver disorders or who can’t convert vitamin D to its active form
what the clinical manifestations of rickets? do they develop suddenly or slowly?
they develop slowly as the bones weaken. skeletal deformities, fractures, delayed growth in height or limbs, dental problems, bone pain, muscle cramps or weakness
progressive condition characterized by abnormal bone destruction and remodeling, which results in bone deformities
Paget’s disease
what occurs in Paget’s disease?
the rate at which old bone is broken down and new bone forms is distorted and bone turnover proceeds at 20 times the normal rate. excessive bone destruction occurs along with the replacement of bone by fibrous tissue and abnormal bone. the new bone is bigger but weakened and filled with new blood vessels. over time, the disease results in fragile misshapen bones
what bones is Paget’s disease most common in?
the pelvis, long bones, the skull, and vertebrae. it may be present in one or two areas on the skeleton or it may occur throughout the body
what is the cause of Paget’s disease?
it is unknown, but thought to be caused by a virus capable of increasing osteoclast activity or genetic defects that produce an increase in interferon 6
what are some complications that may occur with Paget’s disease?
pathologic fractures, osteoarthritis, heart failure, osteosarcoma, and nerve compression
what do the clinical manifestations of Paget’s disease depend on?
the area affected
what are the clinical manifestations of Paget’s disease?
bone pain, skeletal deformities, fractures, headaches, hearing and vision loss, joint pain or stiffness, neck pain, reduced height, warmth over the affected bone, paresthesia or radiating pain in the affected region, hypercalcemia
what are inflammatory joint disorders?
a group of arthritis conditions that are often degenerative in nature. involve inflammation that can be triggered by an autoimmune response, excessive use, increased physical stress, or injury. includes osteoarthritis, rheumatoid arthritis, gout, amkylosing spondylitis
localized joint disease characterized by deterioration of articulating cartilage and its underlying bone as well as bony overgrowth. also known as wear-and-tear arthritis and degenerative joint disease
osteoarthritis
what occurs to the joint during osteoarthritis?
the joint of the cartilage becomes rough and worn, interfering with joint movement. tissue damage triggers the release of enzymes from local cells that accelerate cartilage disintegration. eventually the subchondral bone is exposed and damaged and cysts and osteophytes develop as the bone attempts to remodel itself. pieces of the osteophytes and cartilage break off into the synovial cavity, which further increases irritation. additionally nearby muscles and ligaments become weakened and loose. these changes cause narrowing of the joint space, joint instability, stiffness and pain
what are the most common sites affected by osteoarthritis?
knees, hips, and joint in the hands and spine
is osteoarthritis inflammatory in origin?
no, but inflammation results from tissue irritation.
what causes the erosion of cartilage with osteoarthritis?
it occurs secondary to excessive mechanical stress on the joint. may occur primarily in which the cause is idiopathic
when does disease onset of osteoarthritis usually start?
after age 40
what are the clinical manifestations of osteoarthritis?
joint pain that is exacerbated during or after movement or weight bearing, joint tenderness with light pressure, joint stiffness especially upon rising in the morning or after a period of inactivity, enlarged hard joints, joint swelling, limited joint range of motion, crepitus, hard nodules around the affected joint
a systemic autoimmune condition involving multiple joints
rheumatoid arthritis (RA)
what does the inflammatory process affect in RA?
primarily affects the synovial joints, but may affect other organs
what pattern does RA follow?
it typically follows an autoimmune pattern of remissions and exacerbations
how does RA usually start and progress?
with an initial acute inflammatory episode, after which the joint may appear to recover. the process is repeated with each exacerbation, including synovitis, pannus formation, cartilage erosion, fibrosis, and ankylosis. over time, the recurring inflammation has a cumulative effect as it thickens the synovium which can eventually invade and destroy the cartilage and bone within the joint. the muscles, tendons, and ligaments that hold the joint together weaken and stretch
what joints are affected with RA?
joints on both sides of the body equally. wrists, fingers, knees, feet, and ankles are most commonly affected. gradually, because of the stretching, the joint loses its shape and alignment
what causes RA?
the exact cause is unknown. it is thought that genetic vulnerability permits a virus or bacterium to trigger the disease
what are the risk factors for the development of RA?
family history, advancing age, and smoking. more common in women
what are the clinical manifestations of rheumatoid arthritis?
fatigue, anorexia, low-grade fever, lymphadenopathy, malaise, muscle spasms, morning stiffness lasting longer than 1 hour, warmth, tenderness, and stiffness in the joints when not used for as little as one hour, bilateral joint pain, swollen and boggy joints, limited joint range of motion, contractures and joint deformity, unsteady gait, depression, anemia
inflammatory disease resulting from deposits of uric acid crystals in tissues and fluids within the body
gout
how does gout occur?
normally uric acid dissolves in the blood and is excreted by the kidneys. gout results from an overproduction or under-excretion of uric acid, although not all people with hyperuricemia have gout
who is gout most common in?
African Americans and men
what are factors contributing to the development of gout?
overweight or obesity, cetain diseases, consuming alcohol, using certain medications, and eating a diet rich in meat and seafood
what are the four phases that gout usually follows?
initially the indvidual is asymptomatic, though uric acid levels are climbing in the blood stream and crystals are being deposited in the tissues. over time, these crystals accumulate, damaging tissue. this damage triggers an acute inflammation that characterizes the second phase of gout, referred to as acute flares or attacks. after the acute attack subsides, the person may enter intercritical periods in which the disease remains clinically inactive until the next flare - third phase. continued deposits of crystals in the tissue. in the final stage, chronic gout is characterized by chronic arthritis, associated with soreness and aching of joints
what is a flare distinguished by?
pain, burning, redness, swelling, and warmth at the affected joint lasting days to weeks
what are reoccurent attacks of gout usually precipitated by?
sudden increases in serum uric acid
large, hard nodules composed of uric acid crystals deposited in soft tissue- usually in cooler areas of the body - which can cause a local inflammatory response and drain a chalky fluid
tophi
why might renal calculi be associated with gout?
some are made of uric acid
what are the clinical manifestations of clinical manifestations?
intense pain at the affected joints that frequently starts during the night and is often described as throbbing, crushing, buring, or excrutiating; joint warmth, redness, swelling, and tenderness; fever
how long can a person with gout go without having another attack?
some may go months or even years between gout attacks. they are all varying lengths of time
what do patients who develop chronic arthritis due to gout develop?
joint deformities and limited joint mobility
progressive inflammatory disorder affecting the sarcoiliac joints, intervertebral spaces, and costovertebral joints
ankylosing spondylitis
where does the inflammation associated with ankylosing spondylitis start?
in the vertebral joints
what occurs as the inflammation persists with ankylosing spondylitis?
new bone forms in an attempt to remodel the damage. fibrosis and aalcification, or fusion, of the joints follows the vertebral joints become fixed or ankylosed and lose mobility.
where does inflammation of ankylosing spondylitis start?
in the lower back at the sarcoiliac joints and progresses up the spine
how do the vertebrae appear in ankylosing spondylitis?
the vertebrae appear square, and the vertebral column becomes rigid and loses curvature
what are the roles of the musculoskeletal system?
collaborates with the nervous system to produce movement, stores calcium and other minerals, stores fat, site of hematopoiesis
what is thought to be the cause of ankylosing spondylitis?
the cause is unknown, but genetic factors are thought to be involved.
who is ankylosing spondylitis more common in?
more common in males, typically between the ages of 20-40
what are some complications of ankylosing spondylitis?
kyphosis, osteoporosis, respiratory compromise (due to reduced lung expansion resulting from fusion of the rib cage), endocarditis, and uveitis (inflammation of the eye)
what are the clinical manifestations of ankylosing spondylitis?
intermittent lower back pain, pain and stiffness that typically worsens with inactivity, lower back pain that evolves to include the entire back, pain in other joints, muscle spasms, fatigue, low-grade fever, weight loss, kyphosis
what can chronic muscle disorders lead to?
chronic pain, weakness, and paralysis. may be progressive.
group of inherited disorders characterized by degeneration of skeletal muscle. muscles become weaker as damage worsens
muscular dystrophy
how many different forms of muscular dystrophy are there?
nine different forms, all with their own different patterns of inheritance and pathogenesis
what is the commonality across all forms of MD?
the presence of a muscle protein abnormality. This causes muscle dysfunction, weakness, muscle fiber loss, and inflammation, and it may involve other tissues. fat and fibrous connective tissue eventually replace skeletal muscle fibers.
what are complications of MD?
cardiomyopathy, recurrent respiratory infections, respiratory compromise, death
what are the clinical manifestations of MD?
intellectual disability, muscle weakness that slowly worsens to hypotonia, muscle spasms, delayed development of muscle motor skills, difficulty using one or more muscle groups, poor coordination, drooling, ptosis, frequent falls, problems walking, Gower’s maneuver
progressive loss of joint mobility and contractures, unilateral calf hypertrophy, scoliosis or lordosis
is inflammation associated with fibromyalgia?
no apparent inflammation or degeneration is associated with it
what may be the cause of fibromyalgia?
may be related to an altered central neurotransmission that results in sensitivity to substance P (a neurotransmitter responsible for pain sensation)
what occurs in fibromyalgia?
the brain’s pain receptors seem to develop a sort of pain memory and become more sensitive to pain signals.
who is fibromyalgia more common in?
women
what are conditions that are often associated with fibromyalgia?
RA, systemic lupus erythematosus, and ankylosing spondylitis
