410-412 - Cell junctions, shoulders, knees, and wrists Flashcards
Name the layers of the epidermis
Stratum Corneum (keratin) Stratum Lucidum Stratum Granulosum Stratum Spinosum (spines = desmosomes) Stratum Basale (stem cell site)
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What proteins make up tight junctions?
claudins and occludins
What is another name for tight junction?
zonula occludens
What is the function of the tight junction?
prevents paracellular movement of solutes
Are tight junctions located near the apical or BL surface of the epithelial cell junction?
Apical
What is another name for adherents junction?
zonula adherens
What kind of junction is just below the tight junction in the epithelial junction?
adherens junctions
What is the function of the adherents junction?
forms a “belt” connecting actin cytoskeletons of adjacent cells with CADherens (Ca2+ dependent adhesion proteins)
Loss of which proteins in the inter epithelial junction promotes metastasis?
E-cadherin
What is another name for a desmosome?
macula adherens
What is the function of desmosomes?
structural support via keratin interactions.
What disease is caused by autoantibodies against desmosomes?
pemphigus vulgaris
What proteins make up gap junctions?
connexons
What do gap junctions do?
permit electrical and chemical communication b/w cells
What connects keratin in basal cells to underlying basement membrane?
hemidesmosome
What condition is caused by autoantibodies against hemidesmosomes?
bullous pemphigoid
“hemidesmosomes are down “bullow”
What are membrane proteins that maintain the integrity of the BL membrane by binding to collagen and laminin in the BM?
integrins
What test is used to assess ACL injury?
anterior drawer sign
What test is used to assess PCL injury?
posterior drawer sign
Would you apply valgus stress or varus stress to assess an MCL injury?
valgus
Would you apply valgus stress or varus stress to assess an LCL injury?
varus
What is the McMurray test?
rotation of the knee to assess meniscal tears
Pain on external rotation of the knee indicates injury to which meniscus?
medial meniscus
Pain on internal rotation of the knee indicates injury to which meniscus?
lateral meniscus
What is the unhappy triad?
a common injury in contact sports due to the lateral force applied to a planted leg; classically damage to ACL, MCL, and medial meniscus (attached to MCL); note that lateral meniscus injury is more common
Do “anterior” and “posterior” in ACL and PCL refer to sites of tibial or femur attachment?
tibial
Is the fibula medial or lateral at the knee joint?
lateral
What is an important bony landmark for pudendal nerve block (e.g. to relieve pain of delivery)?
ischial spine
Where is the appendix located with respect to external anatomy?
2/3 of the distance b/w the umbilicus and the anterior superior iliac spine (McBurney point)
What is an important landmark for a lumbar puncture?
iliac crest
What are the shoulder muscles that form the rotator cuff?
SItS: Suprapinatus Infraspinatus Teres minor Subscapularis
What two muscles are innervated by the supra scapular nerve?
Supraspinatus and infraspinatus
What does the supraspinatus muscle do?
abducts arm initially (before the action of the deltoid)
What is the most common rotator cuff injury?
supraspinatus injury
what does the infraspinatus do?
Laterally rotates arm
What injury do pitchers often sustain to the shoulder muscles?
infraspinatus injury
what does the trees minor do?
adducts and laterally rotates arm
what nerve supplies teres minor?
axillary nerve
What nerve supplies the subscapularis?
subscapular nerve
what does the subscapularis do?
medially rotates and adducts the arm
What spinal levels are responsible for rotator cuff muscles?
primarily C5-C6
What are the 8 bones of the wrist? (start at the radial side proximally and make a loop back distally)
Scaphoid, lunate, triquetrum, pisiform, hamate, capitate, trapezoid, trapezium
(So long to pinky, here comes the thumb)
What is the most commonly fractured carpal bone?
scaphoid
Which wrist bone is prone to avascular necrosis owning to retrograde blood supply?
scaphoid
When dislocated, which wrist bone may cause acute carpal tunnel syndrome?
lunate
The ulnar nerve can be injured when this wrist bone breaks in a fall on an outstretched hand:
hamate
What is carpal tunnel syndrome?
entrapment of median nerve in carpal tunnel → compression → paresthesia, pain, and numbness in distribution of the median n.
What is guyon canal syndrome?
compression of ulnar nerve at wrist or hand, classically seen in cyclists due to pressure from handlebars
