Clinical Correlations Flashcards
What are 2 dysfunctions that can happen with occluding junctions?
Increased permeability of occluding junctions results in decreased barrier selectivity
Pathogens target occluding junctions - if they make them dysfunctional, they remove physical barrier to invasion
Claudin 14 mutation
Mutation in protein in occluding junctions that makes those junctions more permeable in organ of corti (affects sound receptor cells)
Can’t generate action potentials
Hereditary form of deafness
H. pylori
Disrupts occludin function or recruits it to the apical domain (from lateral)
Bacteria removes occludin junction barrier and can travel between cells lining the stomach to invade tissue below
What can happen if anchoring junctions are dysfunctional?
Cells can dissociate from each other because of the lack of lateral anchoring
Cells can delaminate from basement membrane without basal anchoring
Pemphigus Vulgaris
Blistering condition
Autoantibodies against cadherins in desmosomes which causes loss of desmosome function (link adjacent cells - lateral domain).
Cells come apart but basal cells remain linked to basement membrane
Bullous Pemphigoid
Blistering Condition
Autoantibodies against type XVII collagen, one of hemidesmosomes TMPS. Loss of hemidesmosomes function that links cells to basement membrane.
Entire epithelium detaches from basement membrane but cells stay linked to adjacent cells
What are carcinomas? How are they classified
Malignant cancers that originate in/from epithelial tissue.
Classified by how far they have spread and based on type of epithelium involved
Why does stress age you?
Cortisol inhibits fibroblast growth and division as well as collagen and elastin deposition
When can inactive fibroblasts reactivate?
Wound healing
White cells usually do not divide. When is the exception?
Morbid Obesity.
When can white fat cells redifferentiate?
Beiging of white fat - become brown fat cells
Results from caloric restriction (gastric bypass, intermediate fasting), or repeated cold exposure
What are Type I hypersensitivity reactions?
Antigens (allergens) cause plasma cells to make IgE antibodies. IgE antibodies bind receptors in cell membrane of mast cells and basophils -> Mast cells now sensitized
Subsequent exposure to allergen binds to IgE antibodies in mast cells and triggers degranulation.
Release of histamine initiates inflammatory response and is also responsible for symptoms associate with allergic reaction
What are the effects of histamine?
Increases blood flow to area - vasodilator
Increases blood vessel permeability - swelling
Increase mucus production
Causes contraction of smooth muscle of bronchi
What is heparin?
Anticoagulant
Binds and inactivates histamine
Modulates intensity of allergic response
Why are mast cells not in CNS?
Inflammation during allergic reactions would cause potentially disruptive edema in CNS - no room for tissue expansion because of skull
Increased permeability of brain capillaries
Benign tumors derived from white fat tissue
Lipomas
What happens when body fat composition is changed?
Affects hormones that regulate metabolism, fat storage, insulin resistance, and inflammation. And thus, one’s ability to gain/lose fat easily
What occurs with hyaline cartilage with age?
Hyaline cartilage in costal cartilage and large airways tend to calcify with age and replaced with bone in geriatric patients.
Perichondritis
Perichondrium infection - pathogens usually enter the area during or after injury. Easier to travel through perichondrium ECM than cartilage matrix.
Common location is perichondrium surrounding elastic cartilage in the pinna of the ear due to ear piercing, sports injury, and ear surgery
What occurs if fibrocartilage is the annulus fibrosis is thinned or damaged?
The nucleus pulposus starts to bulge outward and compress spinal nerve roots.