Overview Snapshot A 40-year-old woman presents with a pruritic rash of 2 weeks duration. She reports a persistent rash over her extremities with very itchy blisters that do not break easily. On physical exam, she has multiple 1-5 cm tense bullae on her abdomen and arms. Skin biopsy with direct immunofluorescence shows linear pattern of IgG and C3 deposits along the epidermal-dermal junction. (Bullous pemphigoid) Tight Junction Tight junction also known as zonula occludens location between adjacent epithelial cells composition claudins occludins function diffusion barrier between adjacent cells prevents paracellular movement of solutes maintains physiochemical separation of tissue compartments Adherens Junction Adherens junction also known as belt desmosome, zonula adherens, and intermediate junctions location between adjacent epithelial cells composition e-cadherin function forms a belt that connects actin cytoskeletons to plasma membrane actin filaments connect with E-cadherin cadherins are Ca2+-dependent adhesion proteins loss of E-cadherins promote metastasis Desmosome Desmosome also known as spot desmosome and macula adherens location between adjacent epithelial cells composition desmoplakin desmoglein connects keratinocytes in stratum spinosum desmocollin function structural support couples intermediate filament to plasma membrane in adjacent cells diseases pemphigus vulgaris autoantibodies target desmoglein component of desmosomes Gap Junction Gap junction location between adjacent epithelial cells composition connexons with central channel function forms channel for electrical and chemical communication between adjacent cells permits exchange of ions, regulatory molecules, and small metabolites through pores Hemidesmosome Hemidesmosome location between epithelial cell and basement membrane composition integrin function connects epithelial cells to underlying basement membrane integrins bind to laminin-5 and type IV collagen, attaching epithelial cell to extracellular matrix diseases bullous pemphigoid autoantibodies target hemidesmosome
QUESTIONS 1 of 3 1 2 3 Previous Next Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK (M1.MK.15.70) A scientist is studying the anatomy and function of bone growth. He is able to create a cell line of osteocytes with a mutation that prevents the osteocytes from exchanging nutrients and waste products within neighboring lamellae. This mutation most likely affected which of the following cell structures? Tested Concept QID: 106483 Type & Select Correct Answer 1 Gap junctions 84% (130/155) 2 Plasma membrane 5% (8/155) 3 Kinesin 1% (1/155) 4 Dynein 3% (4/155) 5 Endoplasmic reticulum 4% (6/155) M 1 Question Complexity E Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review tested concept Sorry, this question is for PEAK Premium Subscribers only Upgrade to PEAK