musculoskeletal, skin, connective tissue-1st A Flashcards
(129 cards)
Epidermis layers Cali Like Girls in String Bikinis
Surface to base 1. Stratum corneum (keratin) 2. Stratum lucidum 3. Stratum granulosum 4. Stratum Spinosum (=desmosomes) 5. Stratum basale (stem cell site)
Epidermal appendages Sebaceous gland
Holocrine secretion of sebum. Hair follicle
Epidermal appendages Eccrine gland
Secretes sweat. Found throughout body (Eccrine glands are Everywhere)
Epidermal appendages Apocrine gland
Secretes milky viscous fluid. Found in axillae, genitalia, atrial. Does not become functional until puberty. Malodorous because of bacteria action
Epithelial cell junctions Tight junction
Zonula occludens- prevent paracellular movement of solutes; composed of claudins and occludins.
Epithelial cell junctions Adherens junction
Zonula adherens- below tight junction, forms belt connecting actin cytoskeleton of adjacent cells with CADherins (Ca2+ dependent ADhesion proteins). Loss of E-cadherin promotes metastasis.
Epithelial cell junctions Desmosomes
Macula adherens- structural support via keratin interactions. Autoantibodies—>pemphigus vulgaris
Epithelial cell junctions Gap junction
Channel protein called connexons permit electrical and chemical communication between cells.
Epithelial cell junctions Hemidesmosome
Connect keratin in basal cells to underlying basement membrane. Autoantibodies–>BULLOus pemphigoid. (Hemidesmosomes are down BULLOw
Epithelial cell junctions Integrins
Membrane proteins that maintain integrity of basement membrane by binding to laminin in BM
Unhappy triad/knee injury Common injury in contact sports
Lateral force applied to a planted leg. Triad includes tear: ACL, MCL, Meniscus (classically medial but lateral more common). Requires surgical ACL reconstruction. Anterior & posterior in ACL & PCL= sites of tibial attachment Positive anterior drawer sign=ACL tear Abnormal passive abduction=MCL tear
Clinically important landmarks Pudendal nerve block Appendix Lumbar puncture
- (Relieve pain of delivery) at ischial spine 2. 2/3 way from umbilicus to anterior superior iliac spine (McBurney’s point) 3. Iliac crest
Rotator cuff muscles in shoulder SItS (small t is for teres minor)
- Supraspinatus-abducts arm initially (before deltoid); most common rotator cuff injury 2. Infraspinatus-laterally rotates arm; pitching injury 3. Teres minor-adducts & laterally rotates arm 4. Subscapularis-medially rotates & adducts arm Innervates by C5-6
Wrist bones: So Long To Pinky, Here Comes The Thumb. 1. Which is commonly fractured? 2. What causes acute carpal tunnel syndrome? 3. What is carpal tunnel syndrome?
Scaphoid Lunate Triquetrium Pisiform Hamate Capitate Trapezoid Trapezium 1.Scaphoid most commonly fractured carpal -prone to avascular necrosis owing to retrograde blood supply. 2.Dislocate of lunate. 3. Entrapment of median nerve in carpal tunnel; nerve compression–> paresthesia, pain, and numbness in distribution of median nerve
Upper extremity innervation routes and common lesions 1.upper trunk 2. Axillary nerve 3. C7 root 4. Lower trunk of brachial plexus 5. Radial nerve in spiral groove 6. Radial nerve 7. Median nerve near elbow 8. Ulnar nerve near elbow 9. Radial nerve (deep branch) 10. Anterior interosseous nerve 11. Median nerve near wrist 12. Ulnar nerve near wrist 13. Recurrent branch of median nerve
1.upper trunk-lesioned by trauma 2. Axillary nerve-lesioned by fracture of surgical neck; dislocation of humerus; intramuscular injections 3. C7 root-compressed by cervical disk lesion 4. Lower trunk of brachial plexus-compressed by cervical rib or Pancoast tumor of lung; leads to Klumpke’s palsy 5. Radial nerve in spiral groove- lesioned by midshalft fracture humerus 6. Radial nerve-compressed in axilla by incorrect use of a crutch 7. Median nerve near elbow-compressed by supracondylar fracture of humerus; pronator teres syndrome 8. Ulnar nerve near elbow-lesioned by repeat minor trauma; fracture of medial epicondyle of humerus 9. Radial nerve (deep branch)-stretchde by subluxation of radius 10. Anterior interosseous nerve-compressed in deep forearm 11. Median nerve near wrist-compressed in carpal tunnel syndrome and by dislocated lunate 12. Ulnar nerve near wrist-lesioned by trauma to hell of hand; fracture of hook of hamate 13. Recurrent branch of median nerve-lesioned by superficial laceration
Upper extremity nerves: Axillary C5-C6 1. typical injury 2. motor deficit 3. sensory deficit 4. sign
- typical injury-fractured surgical neck of humerus, dislocation of humeral head 2. motor deficit- deltoid: arm abduction at shoulder 3. sensory deficit- over deltoid muscle 4. sign- atrophied deltoid consider lesion location; generally muscles innervated by nerve branches distal to lesions will be affected.
Upper extremity nerves: Radial C5-T1 1. typical injury 2. motor deficit 3. sensory deficit 4. sign
- typical injury- fracture at midshaft of humerus; saturday night palsy (extended compression of acilla by back of chair or crutched) 2. motor deficit- BEST extensor Brachioradialis Extensors of wrist & fingers Supinator Triceps 3. sensory deficit- posterior arm and dorsal hand & thumb 4. sign- wrist drop consider lesion location; generally muscles innervated by nerve branches distal to lesions will be affected.
Upper extremity nerves: Median C5-C8, T1 1. typical injury 2. motor deficit 3. sensory deficit 4. sign
- typical injury-fracture of supracondylar humerus (proximal lesion) 2. motor deficit- opposition of thumb, lateral finger flexion, wrist flexion 3. sensory deficit- dorsal & palmar aspects of lateral 3.5 fingers, thenar eminence 4. sign- ape hand; Pope’s blessing (hand) consider lesion location; generally muscles innervated by nerve branches distal to lesions will be affected.
Upper extremity nerves: Ulnar C8, T1 1. typical injury 2. motor deficit 3. sensory deficit 4. sign
- typical injury- fracture of medial epicondyle of humerus, “funny bone” (proximal lesion) 2. motor deficit- medial finger flexion, wrist flexion 3. sensory deficit- medial 1.5 fingers, hypothenar eminence 4. sign- radial deviation of wrist upon wrist flexion consider lesion location; generally muscles innervated by nerve branches distal to lesions will be affected.
Upper extremity nerves: Musculocutaneous C5-C7 1. typical injury 2. motor deficit 3. sensory deficit 4. sign
- typical injury- upper trunk compression 2. motor deficit- biceps, brachialis, coracobrachialis, flexion of arm at elbow 3. sensory deficit- lateral forearm 4. sign consider lesion location; generally muscles innervated by nerve branches distal to lesions will be affected.
Erb-Duchenne palsy (waiter’s tip appearance of the arm)
traction or tear of upper trunk of the brachial plexus (C5-6 roots); seen in infants following trauma during delivery. Findings: -limb hangs by side (paralysis of abductors), -medially rotated (paralysis of lateral rotators), -forearm is protonated (loss of biceps)
Klumpke’s palsy & thoracic outlet syndrome
An embryologic or childbirth defect affecting inferior trunk of brachial plexus (C8, T1); A cervical rib can compress subclavian artery & inferior trunk, resulting in thoracic outlet syndrome: -atrophy of the thenar & hypothenar eminences -atrophy of the interosseous muscles -sensory deficits on the medial side of the forearm & hand -disappearance of the radial pulse upon moving the head toward the ipsilateral side
What joints are involve in distortions of the hand (3)
Clawing is easily conceptualized as loss of the lumbricals, which flex the MCP joints nad extend both the DIP & PIP joints.
Distortion of hand: Ulnar claw -cause -nerve lesion -Inability
1.Can be caused by long-standing injury to ulnar nerve at hook of hamate (falling onto outstretched hand) 2. distal ulnar nerve lesion–>loss of medial lumbrical function–> 3. inability to extend 4th & 5th digits when trying to open hand.