Musculo Skeletal System Flashcards
Describe the structure of skeletal muscle. (Each layer, vascularization, innervation, attachments)
Myofibril–>Muscle fiber–>Fascicle–>Muscle
Highly vascularized and innervated.
Attached to bone by tendons.
Myofibers. Innervated? Job? Attachment/s?
Innervated by motor nerves that cause contraction. Attached to tendons at the myotendinous junction.
Satellite cells
“Stem cells”. Essential for muscular regeneration. Between basal lamina and sarcolemma.
Define sarcolemma
Membrane around each myofiber. “Houses” satellite cells required for regeneration.
Phases of muscle injury?
- Initial damage.
- Formation of hematoma
- Influx of WBC (leukocytes), phagocytosis
Compare “strain” and “sprain”
Sprain- injury to ligaments around joints.
Sprain- Injury to muscles or tendons
What limits muscle shearing during/after injury?
Contraction bands inside myofibril
Which layer is “key” in muscle restoration and healing?
Basal lamina
Stages of muscle healing
- Hemostasis- Hematoma is formed. 24-48 hrs post injury
- Proliferation- After phagocytosis satellite cell and myofibril regeneration. 6-8weeks
- Maturation- Tissue remodeling
Muscle fiber types
Type I-Slow twitch. Very resistant to fatigue
Type IIa- Fast twitch, moderately resistant to fatigue
Type IIb- Fast twitch, not resistant to fatigue.
Degrees of strains
1st- Minor tearing of a few fibers
2nd- Moderate tearing with some loss of function
3rd- Complete tear through muscle unit (either muscle or tendon) with complete loss of function
Define “Osteomalacia”
Soft bone. Known in children as “Rickets”
Cause of Osteomalacia
Lack of Ca+, Vit D, Phosphate. Decreased mineralization at growth plates.
Define Paget’s Dz
Excessive bone growth. S/S pain and stiffness, Fatigue, HA/dizziness, deformity.
T/F Paget’s affects flat bones more than long bones?
False. Affects both but affects long bones more than flat bones
Rickets causes Genu varum or genu valga?
Genu verum.
Pathogenosis of Paget’s?
Old bone breaks down faster. Body responds by building bone faster than normal. Leads to deformity of bones/joints.
Circulatory Dz’s of bone
Aspetic Necrosis.
Legg Calve Pethes.
Osgood Schlatter.
Aseptic Necrosis
bone grows but dies quickly. No microorganisms involved
Legg Calve Perths
Bone growth exceeds blood supply of bone. Primarily affects boys ages 4-8.
Osgoo Schlatters Dz
Repetitive stress injury. Patients tend to be overweight. Primarily affects boys 10-15 and girls 8-13
Inflammatory bone Dz’s
- Ankylosing spondylitis
- Rheumatoid arthritis (RA)
- Gout
- Trauma
- Osteochondritis dissecans
Define Ankylosing spondylitis
“ankylos” means “fusion”. Progressive chronic arthritis of the spine. Spinal rigidity and chronic pain. “bamboo spine”. Question mark Dz referring to spinal deformation. Human Leukocyte Antigen B27 (HLA B27) present in serum of most patients
Rheumatoid Arthritis
autoimmune Dz affecting synovial joins. Multiple joints are affected.
Gout
Condition creating uric acid crystals called “tophi”, in smaller joints.
Osteochondritis Dissecans
Fx through bone and articular cartilage. Difficult to heal and highly susceptible to osteo arthritis (OA) after healing
What does the presence of HLA B27 in joint serum an indication of?
Ankylosing Spondylitis
Whats the most common skin sign of RA?
rheumatoid nodule on extensor side of hand or forearm.
Ulnar drift?
pathoneumonic for RA especially when Rheumatoid Nodule is present.
DDD
Degenerative Disk Dz. Thick and fibrous annulus. Decreased shock absorption through joint which leads to pain.
Heterotopic Ossification (myositis ossificans)
(HO) Bone formation in abnormal places (such as in muscle). Progressive loss of ROM when inflammation should be getting better.
Describe difference between HO and Paget’s
HO-bone growth in muscle or other soft tissue
Pagets- thickening of bone in normal areas
A patient is being seen by a PT following removal of a cast used to fix a fractured humerus. After several weeks, ROM seems to be improving. Suddenly ROM begins decreasing and pt reports no know causes. What might be happening?
Myositis Ossificans (heterotopic ossification)
Osteosarcoma
primary bone neoplasm usually seen in childhood. May occur secondarily to Paget’s.
Chondrosarcoma
Muscular Dystrophy
Most common type is Duchenne MD which is a pediatric condition primarily occurring in pelvic region. Characterized by very large calves NOT due to strength but rather adipose tissue. Cognitive impairments are also common. Gowers sign
Gowers sign
Using hands to walk up legs in order to stand up
Rhabdomyolysis
Increased CPK-MM throughout the body.
Causes of Rhabdomyolysis?
Excessive exercise, heat stroke, ETOH, Viral infection, use of statins.
Polymyalgia Rheumatica
“Muscle Pain”. Hallmarked by painful stiffness that lasts more than 1 hour OOB. Flu like symptoms (FLS)
Myopathy
Nonspecific muscle weakness. Myositis is similar but tends to be more distal while Myopathy is more proximal.
Myofascial pain syndrome
Overuse or stress syndrome marked by presence of TrP’s
TrP stands for?
Trigger points
Latent TrP
not painful but restricts muscle
TTP stands for?
Tender to palpation
