Anatomy and Physiology Flashcards
Extends from lateral femoral condyle to anterior tibia
ACL
Incomplete fracture extending partway through width of bone
Greenstick fracture
Common injury in contact sports from lateral force applied to a planted leg
“Unhappy triad”
“Unhappy triad” consists of injury to what structures
ACL, MCL, and medial meniscus
Which meniscus in the knee is more commonly injured in “Unhappy triad”
Lateral meniscus
Extends from medial femoral condyle to posterior tibia
PCL
Rotator cuff muscles
Supraspinatus, Infraspinatus, Teres minor, Subscapularis
Innervation for supraspinatus muscle
Suprascapular nerve
Most common rotator cuff injury
Supraspinatus muscle
How is supraspinatus injury assessed
Empty/full can test
Action of supraspinatus
Abduction of arm to 15 degrees
Innervation for infraspinatus
Suprascapular nerve
Muscle commonly injured in pitching injury
Infraspinatus
Action of infraspinatus
Laterally rotates arm
Innervation to teres minor
Axillary nerve
Action of teres minor
Adducts and laterally rotates arm
Innervation of subscapularis
Upper and lower subscapular nerve
Action of subscapularis
Medially rotates and adducts arm
Muscle that abducts arm from 15 to 100 degrees
Deltoid
Innervation to deltoid
Axillary nerve
Abducts arm to more than 90 degrees
Trapezius
Innervation to trapezius
Accessory nerve
Abducts arm to more than 100 degrees
Serratus anterior
Innervation to serratus anterior
Long thoracic nerve
Repetitive flexion of elbow causes what injury
Golfer’s elbow
Golfer’s elbow is what injury
Medial epicondylitis
Repetitive extension of elbow causes what injury
Tennis elbow
Tennis elbow is what injury
Lateral epicondylitis
What is the most commonly fractured carpal bone
Scaphoid
Complications of scaphoid fracture
Avascular necrosis and nonunion
Mechanism of avascular necrosis and nonunion in scaphoid fractures
Retrograde blood supply
Dislocation of what wrist bone may cause acute carpal tunnel syndrome
Lunate
90 degree flexion of wrist causing tingling
Phalen maneuver
Percussion to wrist causing tingling
Tinel sign
Classically seen in cyclist due to pressure from handlebars
Guyon canal syndrome
Guyon canal syndrome
Compression of ulnar nerve at wrist or hand
Entrapment of median nerve causing paresthesia, pain, and numbness in distribution of median nerve
Carpal tunnel syndrome
Axillary nerve spinal levels
C5-C6
Musculocutaneous nerve spinal levels
C5-C7
Radial nerve spinal levels
C5-T1
Median nerve spinal levels
C5-T1
Ulnar nerve spinal levels
C8-T1
Recurrent branch of median nerve spinal levels
C5-T1
Nerve commonly injured in anterior dislocation of humerus
Axillary nerve
Nerve commonly injured in upper trunk compression
Musculocutaneous nerve
Nerve commonly injured in carpal tunnel syndrome and wrist laceration
Median nerve
Nerve commonly injured in fracture of surgical neck of humerus
Axillary nerve
Nerve commonly injured in supracondylar fracture of humerus
Medial nerve
Nerve commonly injured in midshaft fracture of humerus
Radial nerve
Nerve commonly injured in fracture of medial epicondyle of humerus
Ulnar nerve
Nerve commonly injured in superficial laceration of palm
Recurrent branch of the median nerve
Nerve commonly injured in fracture of hamate from fall on outstretched hand
Ulnar nerve
Bone fractured from fall on outstretched hand commonly injuring ulnar nerve
Hook of hamate
Ape hand and Pope’s blessing are common presentations of what nerve injury
Median nerve
Flattened deltoid with loss of sensation over deltoid muscle and lateral arm indicates injury to what nerve
Axillary nerve
Loss of elbow, wrist and finger extension indicates injury to what nerve
Radial nerve
Loss of sensation over posterior arm/forearm and dorsal hand indicates injury to what nerve
Radial nerve
Loss of wrist flexion, flexion of lateral fingers, and thumb opposition indicates injury to what nerve
Median nerve
Loss of opposition, abduction and flexion of thumb with no loss of sensation indicates injury to what nerve
Recurrent branch of the median nerve
Nerve commonly injured due to crutches or sleeping with arm over chair
Radial nerve
Loss of wrist flexion, flexion of medial fingers, abduction and adduction of fingers with loss of sensation over medial 1-1/2 fingers indicates injury to what nerve
Ulnar nerve
Loss of sensation over Thenar eminence and dorsal and palmer aspects of lateral 3-1/2 fingers with proximal lesion indicates injury to what nerve
Median nerve
Loss of flexion to lumbricals of 2nd and 3rd digits
Median nerve
Saturday night palsy is injury to what nerve
Radial nerve
Loss of action to medial 2 lumbricals indicates injury to what nerve
Ulnar nerve
Lateral traction on neck during delivery causing adduction, medial rotation, extension and pronation of arm may injure to what part of the brachial plexus
Upper trunk
Nerve roots in upper trunk of brachial plexus
C5-C6
Upward force on arm during delivery may injure what part of the brachial plexus
Lower trunk
Nerve roots in lower trunk of brachial plexus
C8-T1
Erb palsy or “waiter’s tip” is injury to what part of the brachial plexus
Upper trunk
Muscles affected with injury to upper trunk of brachial plexus
Deltoid, supraspinatus, infraspinatus, biceps brachii
Klumpke palsy is injury to what part of the brachial plexus
Lower trunk
Nerve roots in lower trunk of brachial plexus
C8-T1
Compression of lower trunk and subclavian vessels causes which syndrome
Thoracic outlet syndrome
Axillary node dissection after mastectomy or stab wounds can injure what nerve
Long thoracic nerve
Grabbing a tree branch to break a fall can damage what part of the brachial plexus
Lower trunk
Functional deficits seen in winged scapula
Inability to anchor scapula to thoracic cage leading to inability to abduct arm above horizontal plane
Inability to abduct arm above the horizontal is injury to what nerve and muscle
Long thoracic nerve and serratus anterior
Atrophy of intrinsic hand muscles, ischemia, pain and edema due to vascular compression is seen in what syndrome
Thoracic compression syndrome
Mechanism of thoracic compression syndrome
Compression of lower trunk and subclavian vessels
Conditions that commonly cause thoracic compression syndrome
Pancoast tumors and cervical rib
Most common shoulder dislocation
Anterior dislocation
Blood vessel most commonly injured in anterior shoulder dislocation
Posterior circumflex artery
Function of lumbricals
Flexion of MCP, extension of PIP and DIP joints
Ulnar claw is seen with what nerve injury
Distal ulnar nerve injury
Pope’s blessing is seen with what nerve injury
Proximal median nerve injury
What is the deficit in distal ulnar nerve injury
Cannot extend 4th and 5th fingers
What is the deficit in proximal median nerve injury
Cannot flex 1st, 2nd, and 3rd fingers
Median claw is seen in what nerve injury
Distal median nerve injury
OK gesture is seen in what nerve injury
Proximal ulnar nerve injury
What is the deficit in distal nerve injury
Cannot extend 1st, 2nd, and 3rd fingers
What is the deficit in proximal ulnar nerve injury
Cannot flex 4th and 5th digits
Hand cannot do what in proximal median and ulnar nerve injuries
Flex fingers (make a fist)
Hand cannot do what in distal median and ulnar nerve injuries
Extend fingers (open hand)
Which Thenar muscle receives dual innervation
Flexor pollicis brevis
- superficial head - median nerve
- deep head - ulnar nerve
What are the Thenar muscles
Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis
What nerve mainly innervates the Thenar muscles
Median nerve
What nerve mainly innervates the Hypothenar muscles
Ulnar nerve
What are the Hypothenar muscles
Opponens digiti minimi, Abductor digiti minimi, Flexor digiti minimi
Function of palmar interossei muscles
Adduct muscles (PAD)
Function of dorsal interossei muscles
Abduct muscles (DAB)
Nerve for sensory to sole of foot
Tibial
Nerves roots to tibial nerve
L4-S3
Nerve for motor to triceps surae, plantaris, popliteus, and flexor muscles of foot
Tibial
Function of Tibial nerve
Invert and Plantarflex foot (TIP)
Inability to flex toes with loss of sensation on sole of foot indicates injury to what nerve
Tibial nerve
Loss of sensation to dorsum of foot indicates injury to what nerve
Common peroneal nerve
Nerve roots to common peroneal nerve
L4-S2
Foot eversion at rest with loss of inversion and plantarflexion indicates injury to what nerve
Tibial nerve (L4-S3)
Function of Peroneal nerve
Evert and Dorsiflex foot (PED)
Inability to stand on tippy toes indicates injury to what nerve roots
L4-S3
Foot drop indicates injury to what nerve roots
L4-S2
Nerve for motor to biceps femoris, tibialis anterior, and extensor muscles of foot
Peroneal nerve
Inversion and plantarflexion at rest with foot drop while walking indicates injury to what nerve
Peroneal nerve (L4-S2)
Nerve for sensory to suprapubic region
Iliohypogastric
Nerve roots to Iliohypogastric nerve
T12-L1
Abdominal surgery can result in damage to what nerve
Iliohypogastric
Knee trauma or Baker cyst can result in damage to what nerve
Tibial nerve
Knee trauma or Baker cyst presents with what deficits
Foot eversion at rest with loss of plantarflexion
What does the sciatic nerve split into
Common peroneal and tibial nerves
Nerve roots to sciatic nerve
L4-S3
Sensory to posterior thigh
Sciatic nerve (L4-S3)
Common cause of sciatic nerve injury
Herniated disc
Common cause of common peroneal nerve injury
Trauma or compression of lateral aspect of leg
Fibular neck fracture damages what nerve
Common peroneal nerve
Nerve for motor to semitendinosus, semimembranosus, biceps femoris, and adductor magnus
Sciatic nerve
Burning or tingling sensation in surgical incision site radiating to inguinal and suprapubic region indicate injury to what nerve
Iliohypogastric (T12-L1)
Nerve commonly injured in laparoscopic surgery
Genitofemoral nerve
Findings in genitofemoral nerve damage
Decreased anterior thigh sensation below inguinal ligament and absent cremasteric reflex
Nerve commonly damaged with tight clothing and obesity
Lateral femoral cutaneous nerve
Nerve roots to genitofemoral nerve
L1-L2
Nerve for sensory to anterior thigh and medial leg
Femoral nerve
Nerve roots to femoral nerve
L2-L4
Common cause of injury to obturator nerve
Pelvic surgery
Decreased medial thigh sensation and adduction indicates injury to what nerve
Obturator nerve
Nerve roots to obturator nerve
L2-S4
Decreased anterior and lateral thigh sensation indicates injury to what nerve
Lateral femoral cutaneous nerve
Nerve roots to lateral femoral cutaneous nerve
L2-L3
Nerve for motor to adductor longus and brevis, gracilis, pectinus and adductor magnus
Obturator nerve
Nerve commonly injured in pelvic fracture
Femoral nerve
Nerve for motor to quadriceps, iliopsoas, pectinus and sartorius
Femoral nerve
Findings in femoral nerve injury
Decreased thigh flexion and leg extension
Nerve for motor to gluteus maximus
Inferior gluteal
Nerve roots to inferior gluteal
L5-S2
Nerve for motor to gluteus medius, gluteus minimis and tensor fascia latae
Superior gluteal
Nerve roots to superior gluteal
L4-S1
Nerve commonly injured in posterior hip dislocation
Inferior gluteal nerve
Nerve commonly injured in stretch injury during childbirth
Pudendal nerve
Side lesion is located in Trendelenburg sign/gait
Contralateral to the side of dropped hip
Most common cause of superior gluteal nerve injury
Iatrogenic during IM injection to upper medial gluteal region
IM injections should be given in what gluteal region to avoid injuring superior gluteal nerve
Superolateral quadrant
Difficulty climbing stairs, rising from seated position or loss of hip extension indicate injury to what nerve
Inferior gluteal nerve
Nerve for motor to external urethral and anal sphincters
Pudendal nerve
Muscles that abduct hip
Gluteus medius, gluteus minimis
Nerve for sensory to perineum
Pudendal nerve
Muscles that adduct hip
Adductor magnus, longus, and brevis
Muscles that extend hip
Gluteus maximus, semitendinosus, semimembranosus
Fecal or urinary incontinence with decreased sensation to perineum indicate injury to what nerve
Pudendal nerve
Nerve roots to pudendal nerve
S2-S4
Muscles that flex hip
Iliopsoas, rectus femoris, tensor fascia latae, pectineus
Muscles that internally rotate hip
Gluteus medius, gluteus minimis, tensor fascia latae
Muscles that externally rotate hip
Iliopsoas, gluteus maximus, piriformis, obturator
Function of gluteus medius
Abduct and internally rotate hip
Function of gluteus minimis
Abduct and internally rotate hip
Function of gluteus maximus
Extend and externally rotate hip
Function of semitendinosus
Extend hip
Function of semimembranosus
Extend hip
Function of iliopsoas muscle
Flex and externally rotate hip
Function or rectus femoris
Flex hip
Function of tensor fascia latae
Flex and internally rotate hip
Function of pectineus
Flex hip
Function of piriformis
Externally rotate hip
Function of obturator muscle
Externally rotate hip
Intervertebral disc generally herniate in which direction
Posterolaterally
In an L3/L4 disc herniation which nerve is usually affected
L4 (inferior nerve)
Disc level damaged in weakness of plantar flexion, difficulty in toe-walking with decreased Achilles reflex
L5-S1
Disc level damaged in weakness of knee extension with decreased patellar reflex
L3-L4
Disc level damaged in weakness of dorsiflexion with difficulty in heel-walking
L4-L5
Artery commonly damaged with long thoracic nerve
Lateral thoracic artery
Artery and nerve commonly damaged in surgical neck of humerus fractures
Axillary nerve and Posterior circumflex artery
Artery and nerve commonly damaged in midshaft humerus fractures
Radial nerve and deep brachial artery
Artery and nerve commonly damaged in distal humerus or cubital fossa trauma
Median nerve and Brachial artery
Artery and nerve commonly damaged in popliteal trauma
Tibial nerve and Popliteal artery
Artery and nerve commonly damaged in posterior to medal malleolus trauma
Tibial nerve and Posterior tibial artery
Triad of 1 T-tubule + 2 terminal cisternae is in what type of muscle
Skeletal
Action potential depolarization opens what type of channels allowing NT release
Presynaptic voltage-gated Calcium channels
What leads to muscle cell depolarization in the motor end plate
Postsynaptic ligand binding
Depolarization travels along the muscle down what structure
T-tubule
Dyad of 1 T-tubule + 1 terminal cisterna is found in what type of muscle
Cardiac
The dihydropyridine receptor is coupled to what, allowing release of calcium from sarcoplasmic reticulum
Ryanodine receptor
How are the dihydropyridine and ryanodine receptor coupled?
Mechanically coupled
What does binding of calcium to troponin cause in myocytes
Moves tropomyosin exposing myosin-binding groove on actin filaments
Myosin releasing ADP and Pi leading to displacement of myosin on the actin filament is what?
Power stroke
Which band in muscle contraction remains the same
A-band
What bands in muscle contraction shrink
H, I, Z bands
Sarcomere extends from which two bands
I-band to I-band
The center of the sarcomere is what band
M-line
The thick filaments are composed of what protein
Myosin
Thin filaments are composed of what protein
Actin
What causes detachment of myosin head from actin filament
Binding of a new ATP molecule
Hydrolysis of bound ATP causes myosin head to adopt which position
High-energy position (cocked)
What gives type 1 muscle fibers its red color
Increased mitochondria and myoglobin concentrations
Which muscle fibers increase in proportion after weight, resistance training, or sprinting
Type 2 (fast twitch) muscle fibers
What gives type 2 muscle fibers their color
Decreased mitochondria and myoglobin concentrations
Fast twitch muscle fibers use energy through what process
Anaerobic glycolysis
What muscle fibers increase in proportion after endurance training
Type 1 (slow twitch)
Slow twitch muscle fibers use energy through what process
Oxidative phosphorylation
In smooth muscle, membrane depolarization opens what channels
L-type voltage-gated Calcium channels
What does calcium bind to in smooth muscle
Calmodulin
What does calcium-calmodulin complex activate
Myosin-light-chain kinase (MLCK)
What is the function of MLCK
Phosphorylate myosin-light-chain for muscle contraction
How is muscle contraction stopped in smooth muscle
Dephosphorylation of myosin-light-chain by myosin-light-chain phosphatase (MLCP)
Increase in NO in smooth muscle leads to what?
Increase in cGMP activating MLCP causing smooth muscle relaxation
Type of bone formation in bones of axial skeleton, appendicular skeleton and base of skull
Endochondral ossification
What is required for endochondral ossification to occur
Cartilage bone model made by chondrocytes
Type of bone formed directly without cartilage
Membranous bone
What does the cartilage bone model on endochondral ossification get converted to next
Into woven bone and then lamellar bone by osteoblasts and osteoclasts
A person with achondroplasia has a defect in what type of bone formation
Endochondral ossification
Type of bone that occurs after fractures and in Paget disease
Woven bone
What type of environment is required for osteoblast to function
Alkaline environment
Function of osteoblast
Build bone by secreting collagen and catalyzing mineralization
What activates osteoblasts
Increased ALP and alkaline environment
How are osteoclast made
From mesenchymal stem cells in periosteum
Function of osteoclast
Dissolve bone by secreting H+ and collagenases
How are osteoclasts made
From fusion of monocyte/macrophage lineage precursors
What type of environment is required for osteoclasts to function
Acidic environment
At what levels does PTH exert anabolic effects
Low, intermittent levels
What condition do chronically increased PTH levels cause
Osteitis fibrosa cystica
What PTH levels cause catabolic effects on bone
Chronically high PTH levels
What effect do low estrogen levels have on bone
Osteoporosis
What does estrogen cause during puberty
Closure of epiphyseal plate
What inhibits apoptosis in osteoblasts and induces apoptosis in osteoclasts
Estrogen
Failure of longitudinal bone growth and membranous ossification leading to short limbs and large head
Achondroplasia
Constitutive activation of what inhibits chondrocyte proliferation
Fibroblast growth factor receptor 3 (FGFR3)
What is the inheritance pattern of achondroplasia
Autosomal dominant with full penetrance
What is the most common cause of dwarfism
Achondroplasia
Screening for osteoporosis is recommended at what age
> 65 years
What T-score value indicates osteoporosis
T-score of less than or equal to 2.5 or fragility fracture of hip or vertebra
Medical conditions that may cause osteoporosis
Hyperparathyroidism, hyperthyroidism, multiple myeloma or malabsorption syndromes
Drugs that may cause osteoporosis
Steroids, alcohol, anticonvulsants, anticoagulants, thyroid replacement therapy
Most common cause of osteoporosis
Decreased estrogen levels
Lab values associated with osteoporosis
Normal serum calcium and phosphate
What part of bone loss is seen in osteoporosis
Trabecular (spongy) and cortical bone lose mass and interconnections
Treatment for osteoporosis
Bisphosphonates, Teriparatide, SERMS, denosumab
Monoclonal antibody used in osteoporosis
Denosumab
Mechanism of action of bisphosphonates like alendronate
Inhibit osteoclast bone resorption
Prophylactic to prevent osteoporosis
Weight-bearing exercise, adequate calcium and vitamin D intake
Risk factors associated with osteoporosis
Female, increased age, smoking and glucocorticoid use
Failure of normal bone resorption due to defective osteoclasts causing thickened, dense bones prone to fractures
Osteopetrosis
Complications of osteopetrosis
Pancytopenia and extramedullary hematopoiesis
Treatment for osteopetrosis
Bone marrow transplant (curative)
What do defective osteoclasts in osteopetrosis cause
Overgrowth and sclerosis of cortical bone
Cause of pancytopenia in osteopetrosis
Bone fills marrow space
Neurological complications of osteopetrosis
Cranial nerve impingement and palsies
Cause of cranial nerve impingement and palsies in osteopetrosis
Narrowed foramina
Enzyme defective in osteopetrosis
Carbonic anhydrase II
How are osteoclasts impaired in osteopetrosis
Cannot generate acidic environment necessary for bone resorption
Vitamin D deficiency in adults causes what disease
Osteomalacia
Vitamin D deficiency in children causes what disease
Rickets
Defective mineralization of osteoid or cartilaginous growth plates
Osteomalacia - kids
Rickets - adults
Common lab findings in osteomalacia/rickets
Low vitamin D, calcium, and phosphorus
High PTH and ALP
Common findings in osteomalacia
Osteopenia and pseudofractures
Epiphyseal widening, metaphyseal cupping/fraying, genu varum, bead-like costochondral junctions, and craniotabes
Common findings in rickets
Cells involved in lytic stage of Paget disease
Osteoclasts
Lab findings in Paget disease
High ALP
Normal serum calcium, phosphorus, and PTH levels
Treatment for Paget disease of bone
Bisphosphonates (-dronates)
Paget disease increases risk of what complication
Osteogenic sarcoma
Mosaic pattern of woven and lamellar bone with long chalk-stick fractures is seen in what disease
Paget disease of the bone
Cells involved in Quiescent stage of Paget disease
Minimal osteoclast/osteoblast activity
Cells involved in Sclerotic state of Paget disease
Osteoblasts
Cells involved in Mixed stage of Paget disease
Osteoblasts + Osteoclasts
Cardiovascular complication in Paget disease
High-output heart failure from increased blood flow from increased AV shunts
Most common site of osteonecrosis
Femoral head
Cause of avascular necrosis to femoral head
Insufficiency of medial circumflex femoral artery
Caisson or decompression sickness is a risk factor for what
Avascular necrosis
Lab values in osteopetrosis
High serum calcium
Normal phosphorous, ALP, PTH
Brown tumors due to fibrous replacement of bone, subperiosteal thinning indicate what disease
Osteitis fibrosa cystica
Lab values in primary hyperparathyroidism
High serum calcium, ALP, PTH
Low phosphorus
Lab values in secondary hyperparathyroidism
Low serum calcium
High phosphorus, ALP, PTH
Common cause of primary hyperparathyroidism
Idiopathic, parathyroid hyperplasia, adenoma, carcinoma
Common cause of secondary hyperparathyroidism
CKD (low phosphorus excretion and production of activated vitamin D)
Lab values in hypervitaminosis D
High calcium, phosphorus
Low PTH
Most common benign bone tumor
Osteochondroma
Bony exostosis with cartilaginous cap on metaphysis of long bone in young male < 25 years
Osteochondroma
Locally aggressive benign bone tumor with soap bubble appearance on x-ray
Giant cell tumor
Common location of giant cell tumor
Epiphysis of long bones (near knee)
Bone tumor that arises mostly at distal femur and proximal tibia that has cells expressing RANKL
Giant cell tumor
One of the most common malignant bone tumors
Osteosarcoma
Common location of osteosarcoma
Metaphysis of long bones near knee
Treatment for osteosarcoma
Surgical en bloc resection and chemotherapy
Bone tumor with bimodal distribution and Codman triangle or sunburst pattern on x-ray
Osteosarcoma
Bone tumor common in boys < 15 years that appears in diaphysis of long bones with anaplastic small blue cells on biopsy
Ewing sarcoma
Translocation associated with Ewing sarcoma
t(11;22) causing fusion protein EWS-FLI-1
Bone tumor with onion skin periosteal bone reaction that is extremely aggressive with early metastases, but responsive to chemotherapy
Ewing sarcoma
Bone tumor derived from neuroectoderm and onion skin appearance on diaphysis of long bone
Ewing sarcoma
Benign cartilage tumor of small bones of hands and feet
Chondroma
Malignant cartilage tumor in pelvis or central skeleton
Chondrosarcoma
Common cause of osteoarthritis
Mechanical wear and tear of articular cartilage
Cells that mediate degradation and inadequate repair in osteoarthritis
Chondrocytes
Treatment for osteoarthritis
Acetaminophen, NSAID, intra-articular glucocorticoids
Joint disease that presents with pain, swelling, and morning stiffness lasting > 1 hour, improving with use
Rheumatoid arthritis (RA)
Common cause of RA
Pannus formation which erodes articular cartilage and bone
Risk factors for RA
Female, HLA-DR4, smoking, silica exposure
Treatment for RA
NSAIDs, glucocorticoids, disease modifying agents, biologic agents
Biologic agents used for treatment of RA
TNF-alpha inhibitors
Disease modifying agents used for treatment of RA
Methotrexate, sulfasalazine, hydroxychloroquine, leflunomide
RA involves which joints of the hand
MCP, PIP and wrist
Joint findings in osteoarthritis (OA)
Osteophytes, joint space narrowing, subchondral sclerosis, and cysts
Joint disease that presents with pain in weight-bearing joints after use and improving with rest
OA
Joint disease that presents with symmetric joint involvement, systemic symptoms and extra-articular manifestation
RA
Synovial fluid findings in RA
Inflammatory with neutrophils and protein
Cervical subluxation, ulnar finger deviation, swan neck, and boutonniere are common findings in which joint disease
RA
Joint disease that presents knee cartilage loss beginning medially, asymmetric joint involvement with no systemic symptoms
OA
Synovial fluid findings in OA
Non-inflammatory with WBC count < 2000
Wrist joints affected in OA
DIP, PIP, 1st CMC
What is positive rheumatoid factor
IgM antibody that targets IgG Fc region
What test is more specific for RA
Anti-citrullinated peptide antibody
Monosodium crystals causing acute inflammatory monoarthritis
Gout
Medications that exacerbate uric acid
Thiazide diuretics
Lab findings in gout
Needle-shaped crystals, appear yellow under parallel light and blue under perpendicular light
Acute treatment for gout
NSAIDs, glucocorticoids, colchicine
Chronic treatment for gout
Xanthine oxidase inhibitors
Xanthine oxidase inhibitors
Allopurinol, febuxostate
Conditions associated with gout
Lesch-Nyhan syndrome, von Gierke disease, PRPP excess, tumor lysis syndrome
Condition with rhomboid, weakly positive birefringent under polarized light crystals
Calcium pyrophosphate deposition disease
Acute treatment for Calcium pyrophosphate deposition disease
NSAIDs, colchicine, glucocorticoids
Prophylaxis for Calcium pyrophosphate deposition disease
Colchicine
Autoimmune destruction characterized by destruction of exocrine glands by lymphocytic infiltrate
Sjogren’s syndrome
Complications associated with Sjogren’s syndrome
Dental caries, MALT lymphoma, parotid enlargement
Confirmation of Sjogren’s syndrome
Labial salivary gland biopsy
Antiribonucleotide antibodies associated with Sjogren’s syndrome
Anti-Ro and Anti-La
Inflammatory joint pain with decreased tear production and presence of antinuclear antibodies (ANA) indicates what disease
Sjogren’s syndrome
Common causes of septic arthritis
S. aureus, Streptococcus and N gonorrhoeae
Synovial fluid findings in septic arthritis
Purulent synovial fluid with WBC count > 50,000
Triad of polyarthralgia, tenosynovitis, and dermatitis indicate what?
Gonococcal arthritis
Cause of septic arthritis in older adults and children
Staph aureus
Cause of septic arthritis in sexually young adults
N. gonorrhoeae
Treatment for gonococcal arthritis
Ceftriaxone plus azithromycin for possible chlamydial infection
Xerostomia
Decreased salivary production seen in Sjogren’s syndrome
Disease more common in males with bamboo spine on x-ray with involvement of sacroiliac joints
Ankylosing spondylitis
HLA molecule is associated with seronegative spondyloarthritis
HLA-B27
Disease characterized by conjunctivitis, urethritis, and arthritis
Reactive arthritis
Common causes of reactive arthritis
Shigella, Yersinia, Chlamydia, Campylobacter, Salmonella
HLA-B27 associated seronegative spondyloarthritis that presents with uveitis, aortic regurgitation and ankylosis
Ankylosing spondylitis
Associated with asymmetric and patchy skin psoriasis and lesions with “pencil-in-cup” deformity on x-ray
Psoriatic arthritis
Respiratory complication of ankylosing spondylitis
Restrictive lung disease
Diseases characterized by morning stiffness that improves with exercise, strong association with HLA-B27 and presents with dactylitis and uveitis
Seronegative spondyloarthritis
Common cause of death in SLE
Cardiovascular disease, renal disease, infections
SLE antibody that is specific with poor prognosis
Anti-dsDNA antibody
Antibodies sensitive for drug-induced SLE
Anti-histone antibodies
Complement that is deficient in Lupus nephritis
C3, C4
Glomerular deposits seen on EM in lupus nephritis
Subendothelial with IgG and sometimes C3
Light microscopy findings in lupus nephritis
Wire-looping of glomerular capillaries
Immunofluorescent findings in lupus nephritis
Granular appearance
Antibodies that are sensitive but not specific for SLE
Antinuclear antibodies (ANA)
Treatment for SLE
NSAIDs, steroids, immunosuppressants, hydroxychloroquine
Drugs commonly associated with drug-induced SLE
Hydralazine and procainamide
Nonbacterial verrucous thrombi on underside of mitral or aortic valve are indications of what disease
Libman-Sacks Endocarditis
Populations commonly affected by SLE
African-American women of reproductive age
Common presentation of SLE
Malar rash, joint pain, and fever
Women positive for ANA and lupus anticoagulant is at risk for what complication
Spontaneous abortion
Diagnosis of patient with history of thrombosis and anticardiolipin with prolonged PTT
Antiphospholipid syndrome
Treatment for antiphospholipid syndrome
Hydroxychloroquine with SLE and Warfarin plus ASA; possible Rituximab
Disease associated with anti-U1 RNP antibodies with features of SLE and/or polymyositis
Mixed connective tissue disease
Disease associated with anti-beta2 glycoprotein and prolonged PTT not corrected by addition of normal platelet-free plasma
Antiphospholipid syndrome
Disease characterized by immune-mediated, non-caseating granulomas, elevate ACE levels and CD4+/CD8+ ratio on bronchoalveolar lavage
Sarcoidosis
Sarcoidosis is more common in what population
African-American women
Chest x-ray findings in sarcoidosis
Bilateral adenopathy and coarse reticular opacities with hilar and mediastinal adenopathy
Cause of hypercalcemia in sarcoidosis
Increased 1-alpha-hydroxlase-mediated vitamin D activation of macrophages
Disease with epithelioid granulomas containing Schaumann and steroid bodies in African-American female
Sarcoidosis
Treatment for sarcoidosis
Steroids if symptomatic
Disease associated with giant cell arteritis with increased ESR, CRP, normal CK and does not cause muscle weakness
Polymyalgia rheumatica
What age group is more commonly affected with Polymyalgia rheumatica
Women over 50 years
What vasculitides is associated with Polymyalgia rheumatica
Giant temporal arteritis
Treatment for polymyalgia rheumatica
Low-dose corticosteroids
Disease that typically presents with pain and stiffness in shoulders and hips, often with malaise, fever, and weight loss in postmenopausal women
Polymyalgia rheumatica
Disease most commonly seen in premenopausal women associated with paresthesias, poor sleep, non-specific pain and cognitive disturbance
Fibromyalgia
Treatment for fibromyalgia
Regular exercise, antidepressants and anticonvulsants
Disease characterized by endomyseal inflammation with CD8+ T cells, with progressive proximal muscle weakness of the shoulders
Polymyositis
Disease with malar rash, Gottron’s papules, heliotrope rash, shawl and face rash, mechanic’s hands with increased risk of occult malignancy
Dermatomyositis
Dermatomyositis is associated with what type of T-cells and inflammation
Perimysial inflammation and atrophy with CD4+ T-Cells
Lab findings associated with polymyositis and dermatomyositis
Increased CK, positive ANA, anti-Jo-1, anti-SRP, and anti-Mi-2 antibodies
Treatment for polymyositis and dermatomyositis
Steroids plus methotrexate
Most common NMJ disorder
Myasthenia gravis
Pathophysiology of Myasthenia gravis
Autoantibodies to postsynaptic ACh receptors
Diseases associated with myasthenia gravis
Thymoma and thymic hyperplasia
Diagnosis of myasthenia gravis
Edrophonium
Presentation of myasthenia gravis
Ptosis, diplopia, weakness that worsens with muscle use
Treatment for myasthenia gravis
Pyridostigmine
Pathophysiology of Lambert-Eaton syndrome
Autoantibodies to presynaptic calcium channels decreasing ACh release
Presentation of Lambert-Eaton syndrome
Proximal muscle weakness, dry mouth, impotence that improves with muscle use
Disease associated with Lambert-Eaton syndrome
Small cell lung cancer
Primary disease with decreased blood flow to skin due to arteriolar vasospasms in response to cold or stress
Raynaud disease
Treatment for Raynaud syndrome
Calcium channel blockers
CREST syndrome is characterized by what?
Calcinosis, Raynaud’s, Esophageal dysmotility, Sclerodactyly, Telangiectasias
Raynaud’s syndrome is associated with what diseases?
SLE, CREST syndrome, or mixed connective tissue disease
Limited form of systemic sclerosis
CREST syndrome
Disease with triad of autoimmunity, non-inflammatory vasculopathy, and collagen deposition with fibrosis
Scleroderma
Disease manifesting as puffy, taut skin without wrinkles, fingertip pitting with limited skin involvement and CREST syndrome
Limited scleroderma
Disease manifesting as puffy, taut skin without wrinkles, fingertip pitting with widespread skin involvement and associated with anti-Scl-70 antibody
Diffuse scleroderma
Three layers of skin
Epidermis, dermis, subcutaneous fat
How many layers does the epidermis have
5 layers
What are the 5 layers of epidermis
Corneum, Lucidum, Granulosum, Spinosum, Basale
Epithelial junction that prevents paracellular movement of solutes and composed of claudins and occludens
Tight junctions
Tight junctions are located above what?
Adherens junctions
Zona occludens
Tight junction
Adherens junction
Belt desmosome or zona adherens
Epithelial junction below tight junction, forms a belt connecting actin cytoskeletons of adjacent cells with cadherins
Adherens junctions
Loss of which adhesion molecule promotes metastasis
E-cadherins
Pemphigus vulgaris has autoantibodies to which epithelial junction
Desmosomes
Channel proteins that permit electrical and chemical communication between cells
Gap junction
Membrane proteins that maintain integrity of basolateral membrane by binding to collagen and laminin in basement membrane
Integrins
Epithelial junction that provides structural support via intermediate filament interactions
Desmosomes
Bullous pemphigoid has autoantibodies to which membrane protein
Hemidesmosomes
Stem cells are located in what layer of the epidermis
Stratum basale
Which epidermis layer has cells with no nucleus or organelles
Corneum (keratin)
Flat lesion with well-circumscribed change in skin color < 1 cm
Macule
Freckle is what type of lesion
Macule
Macule > 1 cme
Patch
Elevated solid skin lesion < 1 cm
Papule
Papule > 1 cm
Plaque
Small fluid-containing blister < 1 cm
Vesicle
Large fluid-containing blister > 1 cm
Bulla
Vesicle containing pus
Pus
Transient smooth papule or plaque
Wheal
Flaking off of stratum corneum
Scale
Dry exudate
Crust
Increased thickness of stratum corneum
Hyperkeratosis
Hyperkeratosis with retention of nuclei in stratum corneum
Parakeratosis
Increased thickness of stratum granulosum
Hypergranulosis
Epidermal accumulation of edematous fluid in intercellular spaces
Spongiosis
Separation of epidermal cells
Acantholysis
Epidermal hyperplasia (increased spinosum)
Acanthosis
Normal melanocyte number with decreased melanin production
Albinism
Risk increased in albinism
Skin cancer
Mechanism of albinism
Decreased tyrosine activity or defective tyrosine transport
Hyperpigmentation associated with pregnancy or OCP use
Melasma
Irregular areas of complete depigmentation
Vitiligo
Cause of vitiligo
Destruction of melanocytes
Structure consisting of hair, hair follicle, arrector pili muscle, and sebaceous gland
Pilosebaceous unit
Bacteria that causes acne
P. acnes
Causes of acne
Increased sebum/androgen production, abnormal keratinocyte desquamation and P. acnes
Treatment for acne
Retinoids, benzoyl peroxide, antibiotics
Pruritic eruption commonly on skin flexures associated with atopic diseases
Eczema
Ig associated with eczema
IgE
Site of eczema in infants
Face
Site of eczema in children and adults
Antecubital fossa
Type IV hypersensitivity reaction that usually follows exposure to allergen
Allergic contact dermatitis
Cells involved in direct cell cytotoxicity
CD8+ T-cells
Cells involved in delayed-type hypersensitivity
CD4+ T-cells
Melanocyte nevus that is a flat macule
Junctional nevus
Melanocyte nevus that is papular
Intradermal nevi
Common mole that is benign but melanoma can arise in congenital or atypical moles
Melanocyte nevus
Melanocyte nevus common in kids
Junctional nevus
Foreign body inflammatory facial skin disorder characterized by firm, hyperpigmented papules and pustules that are pruritic and painful common in African-Americans
Pseudofolliculitis barbae
Bacteria associated with pseudofolliculitis barbae
Staph and Strep
Treatment for pseudofolliculitis barbae
Mupirocin and warm compresses
Papules and plaques with silvery scaling on knees and elbows
Psoriasis
Pinpoint bleeding spots from exposure of dermal papillae when psoriatic scales are scraped off
Auspitz sign
Collection of neutrophils in stratum corneum seen in psoriasis
Munro microabscesses
Inflammatory facial skin disorder characterized by erythematous papules and pustules, no comedomes and bullous deformation of nose
Rosacea
Common benign neoplasm in older persons with “stuck on” appearance
Seborrheic keratosis
Sudden appearance of multiple stuck on lesions should raise concern for what underlying disease
Malignancy of GI or lymphoid
Sudden appearance multiple seborrheic keratoses
Lese-Trelat sign
Warts on genitals
Condyloma acuminatum
Common cause of Condyloma acuminata
HPV 6 or 11
Soft, tan colored, cauliflower-like papules with epidermal hyperplasia, hyperkeratosis, and koilocytosis
Verrucae
Pruritic wheals that form after mast cell degranulation
Urticaria
Rare blood vessel malignancy in head, neck, and breasts common in elderly on sun-exposed areas
Angiosarcoma
Chemical exposure associated with hepatic angiosarcoma
Vinyl chloride and arsenic
Benign capillary skin papules found in AIDS patients caused by Bartonella infections
Bacillary angiomatosis
Skin papule with neutrophilic infiltrate commonly mistaken for Kaposi sarcoma in AIDS patients
Bacillary angiomatosis
Benign capillary skin papule in elderly that increases with age and does not regress
Cherry hemangioma
Cavernous lymphangioma of the neck associated with Turner syndrome
Cystic hygroma
Benign, painful, red-blue tumor under nails from smooth muscle cells of glomus body
Glomus tumor
Endothelial malignancy associated with HHV-8 and HIV with lymphocytic infiltrate
Kaposi sarcoma
Polypoid lobulated capillary hemangioma that can ulcerate and bleed associated with trauma and pregnancy
Pyogenic granuloma
Benign capillary hemangioma of infancy appearing in first few weeks of life, grows rapidly and regresses by 5-8 years old
Strawberry hemangioma
Honey-colored superficial skin infection associated with Staph or Strep that is high contagious
Impetigo
Bacteria that causes bullous impetigo
Staph aureus
Superficial infection of the upper dermis and superficial lymphatics that presents with well-defined demarcation between infected and normal skin
Erysipelas
Bacteria that causes erysipelas
Strep pyogenes
Acute, painful, spreading infection of deeper dermis and subcutaneous tissue that starts with a break in the skin or another infection
Cellulitis
Bacteria that causes cellulitis
Strep pyogenes or Staph aureus
Collection of pus from a walled-off infection within deeper layers of skin
Abscess
Bacteria that mostly causes abscesses
Staph aureus
Deeper tissue infection with pain out of proportion with crepitus causing bullae and purplish skin color
Necrotizing fasciitis
Cause of crepitus in necrotizing fasciitis
Methane and CO2 production
Bacteria that causes necrotizing fasciitis
Strep pyogenes
Skin infection that destroys keratinocyte attachments in stratum granulosum only and characterized by fever, erythematous rash with positive Nikolsky sign
Scalded Skin Syndrome (SSS)
Cause of SSS
Staphylococcus exfoliative toxin
Umbilicated papules caused by poxvirus frequently seen in children and may be sexually transmitted in adults
Molluscum contagiosum
Presents with multiple crops of lesions in varying stages from vesicles to crusts
Varicella virus
Presents as rash in dermatomal distribution
Zoster virus
Irregular, white, painless plaque on lateral tongue that cannot be scraped off, is EBV mediated and is common in HIV patients and organ transplant recipients
Hairy leukoplakia
Scrapable white plaque on tongue associated with HIV patients
Oral thrush
Component of desmosomes which connect keratinocytes in the stratum spinosum
Desmoglein
Antibody that targets desmoglein
IgG antibody
Potentially autoimmune skin disorder with IgG antibody against desmoglein
Pemphigus vulgaris
Hypersensitivity reaction in pemphigus vulgaris
Type II
What do keratinocytes resemble in pemphigus vulgaris
Row of tombstones
What does IF reveal in pemphigus vulgaris
Antibodies around epidermal cells in a net-like pattern
Pemphigus vulgaris is positive for what sign
Nikolsky sign
Target of IgG antibody in bullous pemphigoid
Hemidesmosomes
Description of blisters in bullous pemphigoid
Tense blisters with neutrophils that spare oral mucosa
What does IF show in bullous pemphigoid
Linear pattern at dermal-epidermal junction
Description of blisters in pemphigus vulgaris
Flaccid intraepidermal bullae caused by acantholysis involving skin and oral mucosa
Pruritic papules, vesicles, and bullae around elbows and associated with celiac disease
Dermatitis herpetiformis
Treatment for dermatitis herpetiformis
Dapsone and gluten-free diet
What antibodies are deposited at tips of dermal papillae in dermatitis herpetiformis
IgA antibodies
Presents with macules, papules, vesicles, target lesions with necrotic center associated with drug reactions and infections
Erythema multiforme
Associated with severe drug reactions characterized by fever, bullae formation, necrosis and targetoid skin lesions with sloughing of skin
Steven-Johnson syndrome (SJS)
More severe form of SJS with > 30% of body surface involvement
SJS-TEN
Epidermal hyperplasia with skin thickening and hyperpigmentation in axilla or neck associated with insulin resistance and visceral malignancy
Acanthosis nigricans
Premalignant skin lesion caused by sun exposure with increased risk of squamous cell carcinoma
Actinic keratosis
Painful, raised inflammatory lesions usually on shins associated with sarcoidosis, cocci, histo, TB, strep infections, leprosy and IBD
Erythema nodosum
Pruritic, Purple, Polygonal, Planar Papules and Plaques with Wickham striae and hypergranulosis
Lichen planus
Skin disorder with saw-tooth infiltrate of lymphocytes at dermal-epidermal junction associated with hepatitis C with mucosal involvement showing reticular white lines
Lichen planus
Skin disease with “Herald” patch followed by other scaly erythematous plaques in “Christmas tree” pattern
Pityriasis rosea
UV light that is dominant in sunburns
UVB light
UV light that is dominant in tanning beds
UVA light
UV light that is dominant in photoaging
UVA light
Exposure to UVA and UVB light increases risk of what?
Basal cell carcinoma, squamous cell carcinoma, and melanoma
Most common skin cancer
Basal cell carcinoma
Second most common skin cancer
Squamous cell carcinoma
S-100 positive tumor with significant risk of metastasis
Melanoma
Tumor that appears as non-healing ulcer with infiltrating growth or a scaling plaque and “palisading” nuclei
Basal cell carcinoma
Common location of BCC
Face and upper lip
What conditions increased risk of BCC
Albinism and Xeroderma pigmentosum
Skin cancer with waxy, pink, pearly nodules commonly with telangiectasias, rolled borders and central crusting or ulceration
BCC
Common location of SCC
Face, lower lip, ears and hands
Locally invasive skin cancer that rarely metastasizes
BCC
Skin cancer with ulcerative red lesions with frequent scales and keratin “pearls”
SCC
Scaly plaque that is a precursor to SCC
Actinic keratosis
Variant of SCC that grows rapidly and may regress spontaneously over months
Keratoacanthoma
Skin cancer associated with excessive sun exposure, immunosuppression, chronically draining sinuses, and arsenic exposure
SCC
Skin cancer associated with sun exposure, dysplastic nevi with increased risk in fair-skinned persons
Melanoma
Mutation that drives melanoma
BRAF kinase mutation
Patients with melanoma who benefit from vemurafenib have what type of mutation
BRAF V600E mutation
Mechanism of vemurafenib
BRAF kinase inhibitor
Primary treatment of melanoma
Excision with appropriately wide margins
Types of melanoma
Superficial spreading, Nodular, Lentigo maligna, and Acral lentiginous
What characteristic of melanoma correlates with risk of metastasis
Depth of tumor (Breslow thickness)
