Flashcards in Musculoskeletal/skin- Anatomy and physiology Deck (85):
What are tight junctions composed of?
claudins and occludins
What are adherens junctions composed of?
Cadherins (Ca2+ dep) and actin cytoskeleton
What do desmosomes connect to?
support keratin interactiosns, desmoplakin
What are the channel proteins in gap junctions?
connexons (permit electrical and chemical communication
What do integrins interact with?
bind collagen and laminin of basement membrane
What type of injury is indicated by the anterior drawer sign?
What are the sites of attachment of the ACL and PCL?
ACL- attaches anterior tibia to lateral condyle of femur (prevents anterior movement of tibia)
PCL- attaches posterior tibia to medial condyle of femur (prevents posterior movement of tibia)
What type of injury is indicated by the posterior drawer sign?
What is the unhappy triad injury?
lateral force applied to a planted leg
ACL, MCL, medial lemniscus
What is the McMurray test of knee pain?
pain on external rotation- medial meniscus
pain on internal rotation- lateral meniscus
What injury is indicated by abnormal passive abduction? (valgus stress)
What injury is indicated by abnormal passive adduction?
What bony marker is used to do a pudendal nerve block?
What boney landmark is used for a lumbar puncture?
What is the innervation and action of the supraspinatus muscle?
Abducts arm initially
What is the innervation and action of the infraspinatus muscle?
latterally rotates arm
What is the most common rotator cuff injury?
injury to supraspinatus
What rotator cuff muscle is a common pitching injury?
What is the innervation and action of the teres minor?
adducts and laterally rotates arm
What is the innervation and action of the subscapularis?
medially rotates and adducts arm
What nerve roots innervate the rotator cuff muscles?
What are the wrist bones?
(So long to pinky, here comes the thumb)
What wrist bone can be palpated in the anatomical snuff box?
What is the most commonly fractured carpal bone? What damage can fracture lead to?
can lead to avascular necrosis
What carpal bone is commonly dislocated? What nerve is damaged by this?
median nerve damaged (acute carpal tunnel)
What nerve and carpal bone can be injured by falling on an outstretched hand?
hook of hamate
What is Guyon canal syndrome? Who typically gets this?
compression of ulnar nerve
cyclists- pressure from handlebars
What nerve is damaged by carpal tunnel syndrome?
median- paresthesia, pain, numbness along distribution
What is damaged by Erb Palsy and what are the functional defecits
upper trunk, C5-C6 roots
abduction, lateral roatation, flexion/supination
What is damaged by klumpke palsy? What are functional deficits?
lower trunk, C8-T1 roots
claw hand (lumbricals, interossei, thenar, hypothenar)
What muscle and nerve are lesioned with a winged scapula?
long thoracic nerve
What is injured from thoracic outlet syndrome? How does this present?
lower trunk, subclavian vessels
same as Klumpke palsy (+ischemia, pain, edema)
Describe the sensory distribution of the median nerve?
palm + distal dorsal of 2nd and 3rd digits
Describe the sensory distribution of the radial nerve?
dorsal surface of thumb+ proximal 2nd and 3rd
Describe the sensory distribution of the ulnar nerve?
4th and 5th digits
What are the muscles of the thenar eminence? What nerve supplies? How would you describe atrophy?
opponens pollicis, abductor pollicis brevis, flexor pollicis brevis
What are the muscles of the hypothenar eminence? What nerve supplies?
opponens digiti minimi, abductor digiti minimi, flexor digiti minimi brevis
What do the dorsal interosseus muscles do?
What do the palmar interosseus muscles do?
What do the lumbrical muscles do?
flex at the MCP joint, extend PIP and DIP
What nerve is injured by fracture of the surgical neck of the humerus?
What nerve is injured by midshaft fracture of the humerus?
What nerve is injured by compression of the axilla?
What nerve is injured by supracondylar fracture of the humerus?
What nerve is injured by medial epicondyle ("funny bone") fracture of the humerus?
What lesion results in a claw with 4th and 5th digits at rest?
distal ulnare nerve
What lesion results in a "pope's blessing" when making a fist?
proximal median nerve lesion
What lesion results in claw of 2nd and 3rd digits when at rest?
distal median nerve
What lesion results in an "OK gesture" when making a fist?
proximal ulnar nerve lesion
How do proximal vs distal lesions of the median /ulnar nerves present?
Distal lesions- clawing at rest (extend at MCP, flex at DIP and PIP)
Proximal lesions- less pronounced, present during voluntary flexion
lesion of what nerve results in wrist drop?
What does superficial laceration of the palm result in?
laceration of recurrent branch of median
loss of thenar muscle group, no loss of sensation
What lesion presents as decreased adduction of the leg?
What lesion presenst as decr thigh felxion and leg extension?
What lesion presents as foot drop, loss of sensation on dorsum of foot?
Common peroneal (L4-S2)
What lesion presents as inabiilty to curl toes and loss of sensation on sole?
What lesion presents as loss of hip extension? (difficulty climbing stairs, rising from seated position)
inferior gluteal (L5-S2)
What lesion presents as tilt of pelvis when standing on one foot?
Superior gluteal (lesioned on standing foot)
What artery supplies the surgical neck of the humerus?
posterior circumflex (axial n)
What artery supplies the midshaft of the humerus?
deep brachial (radial n)
What nerve and artery are present along the distal humerus?
brachial artery, radial n
What nerve and artery are present in the poplitieal fossa?
Popliteal artery, tibial nerve
What nerve and artery are present in the posterior to medial malleolus?
posterior tibial arterh, tibial nerve
What nerve is commonly injured with knee trauma?
What nerve is commonly injured by trauma or compression of the lateral aspect of the leg?
What nerve is commonly injured by pelvic fracture
What nerve is commonly injured by pelvic surgery?
What nerves are commonly injured by posterior hip dislocation?
superior gluteal and inf gluteal
What does Ca2+ bind in muscle?
What is the voltage-sensitive receptor of skeletal muscle? What does it attach to?
Dihydropyridine on cell membrane
attached to ryanodine receptor of sarcoplasmic reticulum
What is the H zone?
Myosin only, at center
shortens with contraction
What is the I band?
shortens with contraction
What is the A band?
length of myosin, doesnt change
What type of metabolism predominates in type 1 vs Type 2 muscle?
Type 1: oxidative phosphyorylation (slow twitch)
Type 2: anaerobic glycolysis (fast twitch- hypertrophy with weight training)
What type of muscle has more mitochondria and myoglobin?`
Type 1- slow twitch
When doe myosin of smooth muscle contract?
Contracts in phosphorylated form- myosin light-chain kinase active
What activates myosin-light-chain kinase?
Ca2+ calmodulin complex
(from L-type voltage gated Ca2+ channel opening)
results in muscle contraction
What activates myosin-light-chain phosphatase?
cGMP (Via NO)
results in muscle relaxation
What do osteoblasts and osteoclasts do?
osteoblast: build bone
osteoclasts: dissolve bone
Describe the origin and appearance of osteoclasts
multinucleate giant cells, secret acid and collagenases
Describe the origin of osteoblasts? Where are stem cells located?
Compare endochondral vs membranous ossification?
Endochondral: cartilagenous model made by chondrocytes, replaced by woven bone, remodeled to lamellar bone
membranous: woven bone formed drirectly, remodeled to lamellar bone (calvarium + facial bone(
What is the effect of estrogen on bone?
inhibits apoptosis of osteoblasts
induces apoptosis of osteoclasts
What are the effects of parathyroid hormone on bone?
Low, intermittent levels- anabolic (build bone)
chronic high levels- catabolic (osteitis fibrosa cystica)