Body Systems: Musculoskeletal Flashcards
bone growth and development
relies on the interplay between 3 constituent factors:
- minerals (calcium and phosphorus embedded in collagen, the bone’s main protein)
- protein (collagen: flexibility to bone, minerals confer hardness and rigidity)
- living cells (osteocytes, osteoblasts, osteoclasts)
three cell types of bone
osteocytes: mature bone cells
osteoblasts: bone-building cells
osteoclasts: bone-resorbing cells
cells receive nutrients through an organized system of blood vessels
bone types
- bones are long, flat, or irregularly shaped
- bone tissues: compact bone, spongy bone
compact bone
bone constituent are arranged in an organized fashion
spongy bone
contains marrow-filled spaces
–> red-marrow is found in these spaces at the end of long bones, and is the site of blood cell formation
long bone
- contains medullary cavity
–> houses yellow-marrow, which consists primarily of fat
bone growth
- long bone growth occurs at the epiphyseal plate (growth plate), an area of cartilage near each expanded end of bone
- during growth, cartilage is converted into bone through ossification
- damage to growth plates during ossification prevents bone form reaching mature length
- cells that are capable of forming new bone tissue in the periosteum
periosteum
- highly vascular layer of fibrous connective tissue covering the surface of bones
- periosteum also serves as a site of attachment for tendons
joints and synovial fluid
- amount of movement at a joint is defined by the shapes of bones and type of connective tissue holding them together
- for freely-moving joints, articulating bones are held together by ligaments
- dense strands of collagen impart great strength to ligaments
synovial membrane
the inner surfaces of joint capsules are lined with a synovial membrane that secrete synovial fluid
–> fluid lubricates the joints
bursae
sacs of synovial fluid situated near certain frequently-moved joints (shoulder, knee) where they reduce friction during movement
–> cartilage on the articulating surfaces of bone also reduces friction
skeletal (voluntary) muscle
tissue is found in muscles that are firmly attached to bones by tendons
- consist of muscle fibre bundles held together by connectives tissue
- upon nerve stimulation at the myoneural junction, muscle fibres contract and shorten, which moves bone
smooth (involuntary) muscle
found in the walls of blood vessels
cardia muscle
an involuntary striated muscles found only in the heart
diagnostic tests and procedures
imaging technologies are required to see tissues
- x-rays and CT reveal fractures, dislocations, bone deformities, and calcification
- MRI visualizes joints, bones, and soft tissues
- arthroscopy is used to visualize the inside of join cavity –> joint fluid can be aspirated for chem analysis
- EMG measures electrical activity of muscles
osteomyelitis
an infectious uncommon bacterial infection of the bone, can occur following bone trauma or in diabetics
osteomyelitis ss
pain, redness, heat, chills, fever, leukocytosis
–> diagnosis can be confirmed with bone biopsy, white blood cell count, MRI, and CT
osteomyelitis treatment
antibiotics, through surgery may be needed to remove necrotic bone tissue
osteomyelitis prevention
treat compound fractures and infections promptly
tuberculosis
- tuberculosis of bone is infectious, rare and associated with untreated pulmonary tuberculosis
- caused by bacterium Mycobacterium tuberculosis
- infection occurs when bacteria spread form the lungs to the bones
- affected bones include the ends of long bones and the vertebrae
tb treatment
antibiotics and/or surgery
prevention
prompt treatment of pulmonary tb will limit spread to bone
vitamin and mineral-deficiency associated disorders
calcium and phosphorous are key to bone health, formation, and maintenance
–> vitamin D is necessary for dietary calcium to be absorbed, deficiencies can lead to soft, malformed, or fragile bones
osteoporosis
a disease characterized by porous bone that is abnormally fragile and susceptible to fracture
- 80% patients are women
- occurs when bone resorption exceeds bone formation
- no symptoms accompany bone loss until bones weaken enough to fracture (pelvis and vertebrae most susceptible)
osteoporosis prevention
diet rich in vitamin D, daily weight-bearing exercises to stimulate bone development, avoid smoking, limit alcohol and caffeine
rickets
rare disease of infancy pr early childhood in which bones do not properly ossify (harden)
- children with rickets develop bones that are soft, bend easily, and become deformed over time
rickets prevention
vitamin D-fortified milk and exposure to sunlight
osteomalacia
softening or calcification of bones in adults
- symptoms: muscle weakness, weight loss, and bone pains
- caused by inadequate dietary vitamin D, deficiency of Ca and P
osteomalacia treatment
vitamin D supplements, calcium-rich diet
Paget’s disease (osteitis deformans)
results in the overproduction of bone, particularly in the skull, vertebrae, and pelvis
- new bone tissue is abnormal and fractures easily
- excessive bony growth causes skull to enlarge, pressing on cranial nerves and may impair vision/hearing
- may also produce curvatures in the spinal column and leg deformities
- diagnosed by examination, x-ray, bone scan, and bone biopsy
Paget’s disease treatment
calcitonin and etidronate, which reduce bon resorption and mithramycin which decreases calcium
scoliosis
an abnormal lateral curvature of the spine
- can be caused by fusion of the vertebrae during development, a neuromuscular abnormality, or weak back muscle development
- symptoms: lower back pain, fatigue
- diagnosis based on physical exam, history, and x-ray
- severe curvatures can be treated with braces or surgery, but cannot be prevented
kyphosis
an exaggerated posterior curve of the thoracic spine that first occurs in adulthood
- caused by osteoporosis-induced vertebral collapse or degenerative arthritis
- symptoms: mild back pain, fatigue, tenderness, and difficulty breathing
- diagnosed with physical exam and x-ray
- treatment options limited, no current cure
bone cancer
malignant bone tumours
- osteogenic sarcoma is a bone cancer that arises in the bony tissue itself and frequently affect the ends of long bones
- cause unknown
- ss: dull localization pain hat intensifies at night, bony masses, fractures near the sarcoma
- diagnosed with biopsy, x-ray, CT
- treatments are chemotherapy to reduce tumour size, followed by surgical removal
bone trauma
trauma is leading cause of bone fractures
- most fractures require immobilization with a splint or cast, others (compound fractures) may require surgery, pins, and plates to heal
bone trauma ss
- visibly out-of-place limb or joint accompanied by intense pain
- swelling, bruising, or bleeding
- numbness and tingling
- broken skin and protruding bone
- limited mobility or inability to move a limb
closed fracture
bone breaks cleanly but does not penetrate skin, can be called simple fracture
open fracture
broken ends of bone protrude through soft tissues and skin, may result in osteomyelitis (serious), can be called compound fracture
comminuted fracture
bone fragments into many pieces, common in those with conditions causing brittle bones
compression fracture
bone is crushed, common in osteoporosis patients
impacted fracture
broken ends of bone are forced into each other, common and results from falls; also common in hip fracture
depressed fracture
broken bone is pressed inward, common in skull fractures
spiral fracture
jagged break due to twisting force applied to bone, common fracture in sports injuries
greenstick fracture
bone breaks incompletely, much in the way a green twig breaks, common in children, whose bones have proportionally more organic matrix and more flexible
arthritis
inflammation of a joint and is a common joint disorder
- ss: persistent joint pain and stiffness, swollen joints, lost mobility, deformed and dysfunctional
- 4 main types:
- rheumatoid arthritis/autoimmune arthritis
- osteoarthritis
- gouty arthritis (gout)
- septic arthritis
rheumatoid arthritis
chronic and debilitating autoimmune disease that affects several joints and their surrounding muscles, tendons, and ligaments
- pathogenesis involves rheumatoid factors (RF) hat form antibody complexes in the synovial fluid of joints –> attracts neutrophils to the joint, causing inflammation and destruction of nearby tissue
- ss: joint pain and swelling, stiffness, fatigue, weakness, weight loss
- progression can result in the formation of thickened granulation that further destroys the joint –> erosion, scarring, and fusion (ankylosis)
- diagnosis with x-rays and RF tests
- cannot be prevented, but treatments involve: disease-modifying anti-rheumatic drugs (DMARDS), anti-inflammatory drugs and immune suppressants
- early treatment most effective
osteoarthritis
- most common form
- primary: occurs with normal ageing
- secondary: associated with joint injury, trauma, or obesity
- degeneration occurs at the articular cartilage that caps the surface of bones in joint (causes underlying bone to be exposed and damaged)
- bone ends thicken and develop spurs, which cause small joints to enlarge and become knobby
- diagnosis requires a physical exam, x-ray of affected joint
osteoarthritis ss
- pain and stiffness in joint
- muscle tension
- muscle fatigue
- affected joints lose their range of motion and associated muscles may weaken
osteoarthritis treatment
- no cure but treatments can relieve pain
- combination of rest, mild exercise, and heat application
- anti-inflammatory mediation
- inject of steroids (cortisone) into joint capsule
- surgical replacement for severe damage
gout (gouty arthritis)
- commonly affects the joints of the hands and feet, particularly the big toe metatarsophalangeal joint
- attacks are related to excess uric acid in blood, resulted from defects in purine metabolism or abnormal retention of uric acids (high levels result in uric acid crystals in joints0
- ss: pain, heat, swelling, and redness of joints
- treatment: rest, application of hot/cold compresses, analgesics, colchicine (chronic), and agents that promote uric acid excretion
septic arthritis
- considered a medical emergency and develops due to bacterial infection of a joint
- streptococci and staphylococci cause septic arthritis by invading a joint after surgery or taruma
- infection may spread into blood from the primary infection site, which can be life-threatening (septicaemia)
- treatment: antibiotics control the joint infection nd prevent speticemia
bursitis
- painful inflammation of bursae, typically in shoulder joint
- common symptoms is pain-induced reduction of joint mobility
- causes: repetitive motion, irritation, or injury of bursa
- treatment: rest, anti-inflammatories, moist heat applications, and steroid injections into affected joint
herniated disks
- ruptures of cartilaginous pad between the bony bodies of adjacent vertebrae
- main cause of lower back pain, a common orthopaedic problem in US
- risk factors: age, obesity, trauma, genetics
- can press on nearby tissues and nerves, causing pain and immobility (common in lumbar region)
- treatments: anti-inflammatories, analgesics, surgery
- cannot be prevented except by reducing known risk factors
dislocation
- displacement of bones from their normal position in a joint (most common in shoulder and inner joints)
- cause pain and reduced mobility at the affected joint
- bone must be reset and immobilized to allow healing of torn ligaments and tendons
sprains
- result from wrenching or twisting a joint that injures the ligaments
- surrounding blood vessels, tissues, muscles, tendons, and nerves may also be damaged
- swelling and discolouration due to hemorrhaging from ruptured blood vessels can occur, followed with extreme pain
- treatments: immobilization of joint withs point or cast, initial cold compresses to reduce swelling, followed by heat compressed to relive discomfort and speed healing
strains (pulled muscles)
- result from the tearing of a muscle and/or its tendon from excessive use or over stretching
- can be prevented by conditioning and warm-up before exercise
- treatments: rest, initial icing to reduce immediate inflammation, followed by heating to encourage blood flow and promote healing
RICE for joint trauma (wait lifeguarding coming in clutch)
Rest: immobilize joint
Ice: reduces inflammation and pain (10min intervals, many times a day)
Compression: immobilizes joint and reduces inflammation
Elevation (above heart level): reduce blood flow to joint, reducing inflammation and pain
carpal tunnel syndrome (CTS)
- painful condition of the hand and is part of the repetitive motion injury class
- affects 10% of working population in US
- risk factors: gender (female), repetitive performance of manual tasks like typing or piano playing
- begins as numbness in the hand but can progress to pain throughout the arm
- diagnosis: physical exam, EMG, nerve conduction analysis
- treatments: avoid repetitive activity, immobilize the hand, injection of steroidal anti-inflammatory drugs into carpal tunnel, surgery (severe)
muscular dystrophy (MD)
- variety of disorders that result in muscle degeneration and physical disability
- different forms are transmitted differently and affect different muscles, but all forms are hereditary
Duchenne’s MD
- most common and serious type: caused by sex-linked gene that affected 2 per 10,000 ppl
- cytoskeletal protein dystrophin is missing in patients
- deficit causes death of muscle fibres, which are replaced by fat and connective tissue
- skeletal muscles progressively weaken, and cardia muscle is affected in severe cases
- diagnosed by EMG showing weak muscle contractions and muscle biopsy
- treatment: physical and occupational therapy, exercise, and use of orthopaedic appliances
- no cure or prevention
myasthenia graves (MG)
- rare autoimmune disorder of myoneural junction in which nerves fault to transmit an impulse to muscle, causing atrophy
- occurs more in females
- cause is unknown and risk factors unclear
- symptoms: fatigue, inability to use voluntary muscles
- respiratory failure is the most severe consequence of this disease
- treatment: drugs that increase acetylcholine levels at the myoneurla junction, removal of enlarged thymus (common)
muscle tumors
- rare, but usually malignant when they occur
- malignant tumours of skeletal muscle called rhabdomyosarcomas
- tumours require surgical removal
- prognosis is poor due to early metastasis
- no known prevention
age-related change to bones
- bone density and strength decline steadily with age due to reduction in osteoblast activity
- bone loss accelerates at menopause, making women significantly more susceptible to osteoporosis
age-related change to joints
- joint mobility decreases with a ge due to reduced synovial fluid production, stiffening of cartilage, and loss of ligament flexibility
- arthritis incidence increases with age
age-related change to muscles
- number, length, and thickness of muscle fibres decrease with age
- this reduces muscle strength and range of motion
- muscles also become less sensitive to stimulation with age
- exercise reduces the rate of these changes and helps maintain muscle mass, strength, and flexibility
bones are soft in rickets due to a deficiency in which vitamin?
vitamin D
what is the most common for of arthritis?
osteoarthritis
biopsy in addition to electromyography (EMG) is a diagnostic test for which disorder?
muscular dystrophy (Duchenne’s MD)
tuberculosis of bone is caused by which bacterium?
mycobacterium tubercolosis
which disorder involves buildup of uric acid in the blood?
gout
what are the principal minerals in bone?
Calcium and Phosphorous
what is the main protein in bone?
collagen (remember for ur face!!)
what cytoskeletal protein is absent is Duchenne’s MD?
dystrophin
