SMB Week 3 Flashcards
A classic chest x-ray involves which two views?
- PA (posterior - anterior)
- Lateral
True or false: a PA view x-ray over-represents the size of the heart due to greater shadowing.
False: an AP view produces greater shadowing
What does an “apple core lesion” suggest?
Colon cancer
Which imaging modality has the best soft tissue contrast?
MRI
The terminal ends of a sarcomere:
Z line
The striations seen in skeletal muscle are due to what?
Alternating bands of thick and thin filaments
Thick filaments in skeletal muscle are composed of what?
Myosin
Thin filaments in skeletal muscle are composed of what?
Actin
How does contraction of skeletal muscle happen?
Actin filaments bind to globular heads of myosin filaments, which causes a conformational change in the myosin heads, bringing the actin filaments closer together.
What are the transverse tubules in a muscle fiber?
Invaginations of the sarcolemma, which is the plasma membrane surrounding a muscle fiber
What is the function of the transverse tubules in a muscle cell?
Allows action potentials to reach the interior myofibrils of the cell.
Action potentials in muscle cells are initiated by what neurotransmitter at the neuromuscular junction?
Acetylcholine
Sites for blocking neuromuscular transmission:
- Presynaptic: Block the release of ACh
- Synaptic cleft: Block breakdown of ACh
- Postsynaptic: Block binding of ACh
Example of a presynaptic toxin:
C. botulinum
Example of a synaptic cleft toxin:
Fasciculin peptides in venom, nerve gas
Therapeutic use: myasthenia gravis
Example of post synaptic toxin:
Suxamethonium (ACh receptor agonist)
Definition of a “twitch”
Response of muscle fiber to a single action potential
Definition of sustained muscle contraction:
Many action potentials trigger multiple contractions. If frequency is high enough, muscle will respond with a “fused tetanus” response.
Definition of isotonic vs. isometric contraction:
Isotonic: tension is constant, length changes
Isometric: length is constant, tension changes
Types of isotonic contraction:
Concentric: muscle shortens (upward part of curl)
Eccentric: muscle lengthens (downward part of curl)
What is the test for De Quervain tenosynovitis?
Finklestein’s test
What are the two tests for carpal tunnel syndrome?
- Tinnel test (tap)
- Phalen’s test (dorsum of hands together)
Most common muscle involved in tennis elbow:
Extensor carpi radialis brevis
What digit can you test to isolate the extensor carpi radials brevis?
3rd (middle finger)
What is the Adson test used for?
To test for subclavian artery compression
What does the Yergason test indicate?
Stability of the long head of the biceps tendon in the bicipital groove
Most commonly injured rotator cuff muscle:
Supraspinatus
What does a positive Neer test indicate?
Subacromial bursitis
What other test is used to detect subacromial bursitis?
Hawkins test
What sort of curvature is the Adams forward bend test measuring?
Axial rotation, not medial/lateral curvature
What muscle does the Trendelenburg test test?
Gluteus medius
What does the pelvic rock test indicate?
Sacroiliac joint stability
What is the Hoover test?
Test to see if a pt is faking a lower back injury. If they’re trying to raise their leg, they’ll counter this motion with an opposite motion in the other leg.
What does a ballotable patella indicate?
Major effusion
Describe the McMurray and Apley tests:
- McMurray: with knee flexed, internally and externally rotate tibia.
- Apley: with pt prone and knee bent at 90 degrees, press down on foot and rotate (compression test for meniscal tear) or pull on foot and rotate (distraction test for ligament damage).
Stages of bone healing:
- Inflammation (1 - 3 days)
- Repair (3 - ? days, soft and hard callus formation)
- Remodeling (removal and replacement of bone)
What is another name for the growth plate?
- Physis
- Also called the epiphyseal plate
What does the term “volar” mean?
Same side as the palm or sole
How is “angulation” used to describe a fracture?
Specifies the direction and amount of displacement from the normal axis of the DISTAL fragment.
Define Impaction, Depression and Compression
Impaction: fractured bones jammed together
Depression: localized area of collapse
Compression: global collapse (usually a vertebral body)
What is an avulsion fracture?
Where a piece of bone is displaced due to a tendon or ligament pulling on it.
Salter-Harris 1
- Physis visibly separated, OR
- Localized pain with normal x-ray
Salter-Harris 2
Fx involves metaphysis, extending into physis
Salter-Harris 3
Fx involves epiphysis, extending into physis
Salter-Harris 4
Fx involves metaphysis, physis and epiphysis
Salter-Harris 5
Physis is compressed
Fractures that need special attention:
- Scaphoid
- Femoral head
- 5th metatarsal (Jones)
Why do scaphoid, femoral head, and 5th metatarsal fractures need special attention?
Poorly vascularized and at risk for necrosis
How do you treat a scaphoid fx?
Thumb spica cast or splint for 8-10 weeks
What is a Jones fx?
Transverse fx through the base of the 5th metatarsal. Caused by trauma or stress
Management of a Jones fx?
Short cast vs. ORIF (open reduction internal fixation)
Smith’s vs. Collie’s fx:
- Smith’s: volar displacement of the distal fragment
- Collie’s: dorsal displacement of the distal fragment
Red flags for lower back pain:
- age > 50 (soft red flag)
- Hx of cancer (hard red flag)
- Other Sx of cancer (weight loss, fever, etc.)
Of strength, endurance and flexibility, which is the most important thing to work on for lower back pain?
Strength
Medical term for bunion:
Hallux valgus
Tx for hallux valgus
- wide toe box
- splint
- surgery
Difference between a corn and a callus:
- Corn: painful keratotic lesion over bony prominence.
- Callus: Diffuse thickening of skin from repeated pressure or friction
Etiology, SSx and management of onychocryptosis:
- Ingrown toenail
- Trimming nails too short, bad shoes, deformity
- Pain, swelling, drainage
- Abx if infected; excision if persistent
Causes of plantar fasciitis:
- fat pad atrophy
- heel spurs
- overuse
Etiology, SSx and Tx of Mortons neuroma:
- inflamed nerve ganglioon in the foot
- pain in forefoot, sensation of pebble in shoe, sensation changes
- tender between 2nd-3rd or 3rd-4th metatarsal heads/necks
- NSAIDS, metatarsal support, injections
What are the Ottawa ankle sprain rules?
Get an x-ray for
- Malleolar pain and tenderness
- Inability to take 4 steps
- AP, lateral, Mortise view
Exam for suspected ankle fx:
- Point of tenderness
- Stability
- Neurovascular status
- Examine the knee
What do you look for in a Mortise view that would indicate surgery?
- widening on either side of the talus
- indicates an unstable ankle
Maisonneuve fx:
Spiral fibular fx of proximal 1/3 of fibula with associated medial malleolus injury.
MOA, indication, contraindication, AE’s, dosing, monitoring, pt ed for acetaminophen:
MOA:
- Inhibits heat regulating center in hypothalamus
- weak antagonist of cyclo-oxygenase. MOA for analgesia unclear
Indications:
- Analgesic and antipyretic, good for non-injury pain
AEs:
- Low GI effects, hepatotoxicity
Dosing:
- Adults 325 - 650 mg q 4-6 hrs or 1g q 6-8 hrs
- Max 4g/day (2g/day with liver disease)
MOA, indication, contraindication, AE’s, dosing, monitoring, pt ed for aspirin:
MOA:
- Acetylates platelets, removing them from circulation
Indications:
- Analgesic, anti-inflammatory and antipyretic
AEs:
- GI effects, skin rashes, bleeds, possible Reye’s syndrome in children during febrile illnesses.
Dosing:
- Adults 325 - 650 mg for analgesia, antipyretic effect.
- 4-6 g/day for anti-inflammatory
- 81-325 mg/day for anti platelet
MOA, indication, contraindication, AE’s, dosing, monitoring, pt ed for NSAIDS:
MOA:
- Inhibits cycle-oxygenase, so inhibits prostaglandins and leukotrienes
- Cox 1 enzymes (lower gastric acid, increased mucus viscosity and gastric blood flow; also happens in kidneys)
- Cox 2 enzymes induced during/by inflammation, cytokines
Indications:
- Analgesic, anti-inflammatory and antipyretic
AEs:
- GI effects, renal insufficiency
Dosing:
- Depends on drug used. Efficacy similar but different potencies.
Celecoxib (Celebrex)
Cox II selective inhibitor
MOA, indication, contraindication, AE’s, dosing, monitoring, pt ed for opiates:
MOA:
- Opiate receptors in spinal cord, brain stem and higher centers
- Mimics action of endogenous endorphins
- Inhibit release of Substance P
- Inhibit transmission of nociceptive input to spinal cord, as well as descending inhibitory pathways.
Indications:
- Moderate to severe pain
AEs:
- Somnolence, respiratory depression, N/V, constipation
Dosing:
- Start with low dose and short acting formulations until pain well-controlled.
Diagnosing tendinitis:
- Pain with palpation
- Pain with passive stretch
- Pain with contraction against resistance
H zone
The region straddling the M line, occupied only by thick filaments
A band
The area between I bands, occupied by both thick and thin filaments
I band
The area straddling the Z line, occupied only by thin filaments
The 3 types of muscle fibers and their strength/endurance properties:
- Slow oxidative fibers: weak but high endurance
- Fast oxidative glycolytic fibers: intermediate strength and endurance
- Fast glycolytic fibers: high strength but low endurance
True or false: many rotator cuff tears are asymptomatic, especially in older adults.
True
What sort of movements are likely to be limited in someone with a rotator cuff tear?
Overhead motion, abduction and internal rotation.
Test for torn supraspinatus
Empty can test: 70 degrees abduction, 30 degrees forward flexion, internal rotation. Press down on arm against resistance.
Management of torn rotator cuff:
Surgical referral in individuals 60.
Test for acromioclavicular strain:
Cross arm adduction test.
Ottawa rules for ankle injury:
- bony tenderness at distal, posterior malleoli
- inability to bear weight
- pain with palpation of navicular or 5th metatarsal
Osgood-Schlatter disease
Involves inflammation of the patellar tendon where it attaches to the tibial tuberosity
