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Step 1 11.30.12
Muscle I
| Question | Answer |
|---|---|
| What are the 5 layers of the epidermis surface to base? Mnemonic? | Californians Like Girls in String Bikinis : 1. stratum corneum 2. stratum lucidum 3. stratum granulosum 4. stratum spinosum 5. stratum basalis |
| What is the role of a sebaceous and whit what is it associated? | holocrine secretion of sebum. associated with hair follicle |
| What is the role of an eccrine gland and where are they found? | secretes sweat, found throughout the body |
| What is the role of an apocrine gland, where are they found, and when do they become active? | make milky viscid secretions that become odorous due to bacterial action. found in axila, genitalia and aereolae. not functional until puberty |
| What are the 4 epithelial cell junctions, apical to basal? | zona occludens, zona adherens, macula adherens, gap junctions |
| What is the role of zona occludens (tight junction)? What is it composed of? | tight junctions. prevents diffusion across the paracellular space. composed of claudins and occludins |
| What is the role of the zona adherens, what is it composed of and on what ion does it depend? | intermediate junction. cadherins connect actin filaments of adjacent cells. these depend on Ca++ |
| What is the role of the macula adherens, what are they composed of? | desmosomes. small discrete sites of attatchment between intermediate filaments by cadherens, autoAb-->pemphigus vulgaris. have keratin and desmoplakin |
| What is the role of a gap junction, what is it composed of? | allows adjacent cells to communicate for electric and metabolic functions. composed of connexons with central channels |
| What does an integrin do for an epithelial cell? | maintians integrity of BM, binds to laminin in BM |
| What is the role of the hemidesmosome in the epithelial cell junction? | connects cells to underlying ECM. autoab-->bullous pemphigoid |
| What is the "unhappy triad" in knee injury? What sport and what is the mechanism of injury? | football injury with force from lateral side. 1. medial collateral lig (MCL) 2. Anterior cruciate (ACL) 3. lateral meniscus (NOT medial) |
| What does anterior and posterior in ACL and PCL refer to? | points of tibial attatchment |
| What does a positive anterior drawer test indicate? | tearing of ACL |
| What does a abnormal passive abduction of the knee indicate? | torn MCL |
| Where is a pudendal nerve block made? When is it used? | at the ischial spine for pain of delivery |
| Where is McBurney's point? What is it? | appendix. 2/3 of way from umbilicus to anterior superior iliac apine |
| Where is a lumbar puncture performed? | iliac crest |
| What is the mnemonic for the muscles of the rotator cuff? | SItS (supraspinatus, infraspinatus, teres minor, subscapularis) Superior--->posterior--->anterior |
| What is the function of the supraspinatus? | abducts arm initially before deltoid. most commonly injured |
| What is the function of the infraspinatus? When is it commonly injured? | laterally rotates the arm. pitching injury |
| What is the function of teres minor? | adducts and laterally rotates arm |
| What is the function of subscapularis? | medially rotates and adducts arm |
| What are the bones of the hand and wrist? Mnemonic? | Some Lovers Try Positions That They Can't Handle: scaphoid. lunate, triquetrum, pisoform, trapezium, trapezoid, capitate, hamate (medial to lateral to pisoform, then medial to lateral again) |
| What bone is commonly injured on a fall on the outdstretched hand? | scaphoid |
| What injury can compress the C7 root? | cervical disk lesion |
| When can the lower trunk of the brachial plexus be injured? What can it lead to? | compressed by cervical rib or pancoast tumor of lung. leads to Klumpke's palsy |
| What nerve is compressed the inappropriate use of a crutch? | radial n. |
| What nerve is injured by fracture of the surgical neck of the humerus, dislocation of the humerus, or IM injections? | axillary n. |
| What nerve is injured by a midshaft fracture of the humerus? | lesioned by midshaft fracture of the humerus |
| What nerve is injured in a repeat minor trauma or fracture of the medial epicondyle of the humerus? | ulnar n. |
| What nerve is injured by a supracondylar fracture of the humerus, or pronator teres syndrome? | median n. |
| What nerve can be stretched by subluxation of the radius? | deep branch of the radial n. |
| What nerve can be compressed in the deep forearm? | anterior interosseous n. |
| What nerve is injured in carpal tunnel syndrome or a dislocated lunate? | median n. |
| What nerve is injured by a lesion to the heel of the hand or fracture of the hook of the hamate? | ulnar n. |
| What nerve might be injured by a superficial laceration of the meaty part of the base of the thumb? | recurrent br. of the median n. |
| What dermatome is the ring finger and pinky on the palm? | C8 |
| What dermatome is the middle finger on the palm? | C7 |
| What is the dermotome of the thumb, index finger, and lateral forearm in the palm? | C6 |
| What does C8 supply on the back of the hand? | pinky and half of ring finger, lateral half of hand on back |
| What does C7 supply on the back of the hand? | distal index and middle and medial half of ring |
| What does C6 supply on the back of the hand? | thumb and medial half of hand not fingers |
| What nerve coincides with the C8 dermatome? | ulnar n. |
| what nerve coincides with the c7 dermatome? | mediant n |
| What nerve coincides with the C6 dermatome? | superficial branch of the radial n. |
| What are the 5 parts of the brachial plexus? Menomic? | Randy travis drinks cold beer: roots, trunks, divisions, cords, braches |
| What does a lesion of the upper trunk of the brachial plexus cause? What roots are invovled? | Waiter's tip (Erb's palsy), C5 and C6 |
| What does a lesion of the lower trunk of the brachial plexus cause? What roots are invovled? | Claw hand (Klumpke's palsy), C8 and T1 |
| What does a lesion of the posterior cord of the brachial plexus prior to the bifurcation? Nerve roots? | wrist drop. contricutions from all roots |
| What does a lesion of the long thoracic nerve cause? What nerve roots? | winged scapula, C5, C6, C7 |
| What does a lesion of the axillay branch of the posterior cord cause? | deltoid paralysis |
| What does a lesion of the radial branch of the posterior cord cause? | saturday night palsy (wrist drop) |
| What does a lesion of the musculocutaneous branch of the brachial plexus cause? | difficult flexing elbow, variable sensory loss |
| What does a lesion of the median branch of the brachial plexus cause? | decreased thumb flexion, Pope's blessing |
| What does a lesion of the ulnar branch of the brachial plexus cause? | intrinsic muscles of the hand palsy, claw hand |
| What protects the brachial plexus in a fracture of the clavicle? | subclavius muscle |
| What roots is the axillary n composed of? | C5, C6 |
| A difficulty in arm abduction at the shoulder is what muscle and what nerve? | deltoid, Axillary (C5,C6) |
| Where is the sensory deficit in an injury to the axillary nerve? | over deltoid muscle |
| A flattened deltoid is a sign of injury to the? | axillary n (C5, C6) |
| What are 2 common mechanisms for axiallary nerve injury? | fracture of surgical neck of humerus, dislocation of the humeral head |
| What are 2 common mechanism for injury to the radial nerve in the upper extremity? | fracture at the midshaft of the humerus, Saturday night palsy (compression of axilla by chair or crutches) |
| What nerve roots make up the radial n? | C5-C8 |
| What motor deficit would you expect to see in radial nerve injury? | BEST extensors: brachioradialis, extensors of the wrist and fingers, Supinators, Triceps |
| A sensory deficit in the posterior arm, dorsal hand and dorsal thumb is injury to what nerve? | radial n. C5-C8 |
| Wrist drop points to damage in what nerve? | radial n. |
| What nerve roots compose the median n.? | C5-C8, T1 |
| What is a common mechanism for a proximal lesion of the median n? | fracture of the supracondylar humerus |
| What are 2 common mechanisms of the distal median n? | carpal tunnel syndrome or dislocated lunate |
| A proximal lesion of the median nerve would cause what motor deficit? | opposition of the thumb difficult |
| A distal median nerve lesion would cause what motor deficit? | lateral finger flexion and wrist flexion impairment |
| What sensory deficit would you see if the proximal median n erve were injured? | dorsal and palmar aspects of lateral 3.5 fingers, thenar eminence |
| what sensory deficit would you expect to see if the distal median nerve were injured? | dorsal and palmar aspects of the lateral 3.5 fingers |
| What is "ape hand", thenar atrophy, and loss of opposability of the thumb a sign of? | proximal median nerve damage (C5-C8, T1) |
| What is claw hand, ulnar deviation of wrist upon wrist flexion a sign of? | lesion of the distal median nerve (C5-C8, T1) |
| What nerve roots compose the ulnar n? | C8,T1 |
| What is a common mechanism of injury for the proximal ulnar n? | fracture of the medial epicondyle of the humerus (funny bone) |
| What is a common mechanism of injury of the distal ulnar n? | fracture of the hook of the hamate by falling onto an outstretched handle |
| What motor deficit might you see if the proximal ulnar nerve is injured? | medial finger flexion, wrist flexion |
| what motor deficits might you see if the distal ulnar nerve is injured? | abduction and adduction of fingers (interossei), adduction of thumb. extension of the 4th and 5th fingers (lumbricals) |
| What sensory deficits would you expect to see if the proxiaml ulnar nerve is injured? | medial 1.5 fingers, hypothenar eminence |
| Radial deviation of the wrist upon wrist flexion is a sign of? | ulnar nerve |
| An ulnar claw hand when asked to straighten fingersa or a hand of benediction is a sign of injury to? | the distal ulnar n. |
| What nerve roots make up the musculocutaneous nerve? | C5-C7 |
| What is the a common mechanism of musculocutaneus n injury? | upper trunk compression |
| What motor deficits would you expect in an injury of the musculocutaneous nerve? | biceps, brachialis, coracobrachialis. flexion of arm at the elbow |
| What sensory deficits might you expect to see if the musculocutaneous nerve is injured? | lateral forearm |
| What is the injury in Erb-Duchenne waiters tip and when does it commonly happen? | traction or tear in C5 and C6 roots in brachial plexus. see in blow to shoulder or trauma during delivery |
| A limb hanging by the side, medially rotates with a pronated forarm is what injury? What is the mech? | = waiters tip (C5 and C6 roots). hanging limb= loss of abductors. medially rotated=loss of lateral rotators. pronation=loss of biceps |
| What is the injury in Klumpke's palsy/throacic outlet syndrome? How does it happen? | embryological or childnirth defect affecting inferior trunk of brachial plexus (C8,T1), cerviccal rib can compress subclavian artery and inferior trunk |
| What are 4 major findings in Klumpke's palsy/throacic outlet syndrome? | 1. atrophy of thenar and hypothenar eminences 2. atrophy of the interosseous muscles 3. sensory deficits on medial side of forearm and hand 4. disappearance of the raidal pulse upon moving the head toward the ipsilateral side |
| What is the role of the lumbrical muscles? | flex MCP, extend DIP and PIP joints |
| What is an ulnar claw? What is the mechanism? | distal ulnar nerve lesion-->loss of medial lumbrical function; 4th and 5th digits clawed (Pope's blessing). Cant extend 4th and 5th. |
| how can you tell the difference between Pope's blessing and proximal median nerve damage? | making a fist with proximal median can look like Pope's. Pope's is an issue of cant extend vs cant flex in median |
| What is the injury in a median claw and what is the mechanism? | distal median mnerve lesion (after C5-C7 branches off to forearm flexors)--> loss of lumbrical function in 2nd and 3rd digits. |
| What fingers cant do what in median claw? | 2nd and 3rd digits cant be extended |
| What is the injury and mechanism of Ape hand? | proximal median nerve lesion-->loss of opponens pollicis muscle function-->unopposable thumb (cant abduct thumb) |
| What is the injury and mechanism of Klumpke's total claw? | lesion of lower trunk (C8,T1) of brachial plexus--> loss of function of all lumbricals;forearm finger flexors (fed partiall by C5-C7) and finger extensors (fed by radial nerve) are unopposed = clawing of all digits |
| What happens in a long thoracic nerve injury? What muscle is denervated? What surgery might injure it? | get winged scpaula due to dennervation of serratus anterior. Can be injured in mastectomy |
| What are the 3 thenar muscles? What nerve supplies them? | opponens pollicis, abductor pollicis brevis, flexor pollicis brevis. Oppose abduct, flex. supplied by median nerve |
| What are the 3 hypothenar muscles? What supplies them? | opponens digiti minimi, abductor digiti minimi, flexor digiti minimi. all supplied by ulnar nerve. Oppose, Abduct, flex |
| What is the function of the dorsal interossei? | abduct the fingers (DAB) |
| What is the function of the palmar interossei? | adduct the fingers (PAD) |
| What nerve roots make up the obturator nerve? | L2-L4 |
| What is a common mechanism of the obturator nerve? | anterior hip dislocation |
| What motor deficit would you see in obturator nerve injury? | thigh adduction |
| What sensory deficit would you see in an obturator n injury? | medial thigh |
| What nerve roots make up the femoral nerve? | L2-L4 |
| What is a common mechanism of injury of the femoral nerve? | pelvic fracture |
| What motor deficit would be seen if a femoral nerve injury? | thigh flexion and leg extension |
| What sensory deficit would be seen in femoral nerve injury? | anterior thigh and medial leg |
| What nerve roots make up the common peroneal nerve? | L4-S2 |
| What is a common mechanism of injury to the common peronmeal nerve? | trauma to lateral aspect of leg or fibula neck fracture |
| What motor deficit would be seen in injury of the common peroneal nerve? | foot eversion and dorsiflexion, toe extension, foot drop, foot slap, steppage gait |
| What sensory deficit might be seen in a common peroneal nerve injury? | anterolateral leg and dorsal aspect of foot |
| What is a common mechanism of injury for the tibial nerve? | knee trauma |
| What roots make up the tibial nerve? | L4-S2 |
| What motor deficit might be seen in an injury to the tibial nerve? | foot inversion and plantar flexion, toe flexion |
| What sensory deficit might be seen in an injury to the tibial nerve? | sole of foot |
| What nerve roots make of the superior gluteal nerve? | L4-S1 |
| What is a common mechanism of injury for the superior gluteal nerve? | posterior hip dislocation or polio |
| What is the motor deficit seen in injury to the superior gluteal nerve? | thigh abduction (positive Trendelenberg sign) |
| What is a positive Trendelenberg sign? | contralateral hip drops when standing on leg ipsilateral to site of lesion |
| What nerve roots make up the inferior gluteal nerve? | L5-S2 |
| What is a common mechanism of injury of the inferior gluteal nerve? | posterior hip dislocation |
| What is the motor deficit seen in an injury to the inferior gluteal nerve? | cant jump, cant climb stairs or rise from seated position. cant push inferiorly (downward) |
| What is a a useful mnemonic for peroneal nerve injury and funtion? | PED= peroneal everts and dorsiflexes. injured=dropPED |
| What is a useful mnemonic for tibial nerve injury and function? | TIP= tibial inverts and plantarflexes. if injured cant stand on TIPtoes |
| What is the sciatic nerve? | made of L4-S2. posterior thigh, splits into common peroneal and tibial nerve |
| What are the 1st 3 steps in muscle contraction? | 1. AP depolarization opens VG Ca++ channesl, inducing NT release 2. PSyn ligand binding leads to muscle cell depolarization at the motor end plate 3. depolarization travels along muscle cells to t tubule |
| What are the next 2 steps in muscle contraction? | 4. depol of voltage sensitive dihydropyridine receptor coupled to ryanodine recpetor on SR induces conformational change causing Ca++ release from SR 5. released Ca++ binds troponin C, which moves tropmysoin out of myosin binding groove |
| What is the final step in excitation contraction coupling? | 6. myosin release bound ADP and is displced on actin filament (power stroke). contraction results in H and I bacd shortening but A is same length |
| What bands change size in contraction? | A band=always the same. HIZ=shrinkage |
| What is a type 1 muscle fiber? | slow twitch. red fibers due to incr mitochondria and myoglobin (more oxidative phosphorylation and sustained contraction) |
| What is a type 2 muscle fiber? | fast twitch. white fibers due to less mitochondria and less myoglobin (incr in anaerobic glycolysis |
| What muscle fibers hypertrophy in weight training? | Type 2 muscle fibers |
Created by:
tjs2123
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