Tight junction (aka zonula occludens)
prevents paracellular movement of solutes; composed of claudins and occludins
Adherens junction (aka zonula adherens)
below tight junction; forms belt connecting actin cytoskeletons of adjacent cells with cadherins
Ca2+ dependent adhesion proteins.
Loss of E-cadherin promotes...
Desmosome (macula adherens)
structural support via keratin interactions
Autoantibodies to the desmosome cause...
channel proteins called connexons permit electrical and chemical communication between cells
membrane proteins that maintain the integrity of basolateral membrane by binding to collagen and laminin in the basement membrane
connects keratin in basal cells to the underlying BM
Autoantibodies to the hemidesmosome leads to...
bullous pemphigoid (hemidesmosomes are down "bullo")
Anterior drawer sign tests for...
Posterior drawer sign tests for...
Valgus stress (abduction) tests for....
Varus stress tests for (adduction)....
pain on external rotation = medial meniscus pain on internal rotation = lateral meniscus
injury due to lateral force applied to planted leg; consists of damage to ACL, MCL and medial meniscus (or lateral meniscus)
Pudendal nerve block is given....
to relieve the pain of delivery into the ischial spine.
Rotator Cuff Muscles
Supraspinatus Infraspinatus Teres minor Subscapularis
-suprascapular nerve -abducts arm initially -most common rotator cuff injury
-suprascapular nerve -laterally rotates arm -pitching injury
-axillary nerve -adducts and laterally rotates arm
-subscapular nerve -medially rotates and adducts arm
The most commonly fractured carpal bone is...
the scaphoid bone and it is prone to avascular necrosis due to retrograde blood supply. It can be palpated in the anatomical snuff box.
Dislocation of the lunate may cause...
acute carpal tunnel.
A fall on an outstretched hand that damages the hook of hamate can cause...
ulnar nerve injury.
Carpal Tunnel Syndrome
entrapment of median nerve leading to parestesia, pain and numbness
Guyon Canal Syndrome
compression of the ulnar nerve classically seen in cyclists
Erb Palsy is an injury of the...
upper trunk caused by lateral traction on infant's neck during delivery or trauma in adults.
Erb Palsy Muscle/Functional Deficits
Deltoid/Supraspinatus - abduction (arm hangs by side) Infraspinatus - lateral rotation (arm is medially rotated) Biceps brachii - flexion, supination (arm extended and pronated)
Klumpke Palsy is an injury of the....
lower trunk due to upward force on infant arm during delivery or adult trauma.