A&P Quiz 2 Flashcards
What are the types of Cell Junctions?
Tight Junction
Desmosomes
Hemidesmosomes
Gap Junction
Tight Junction
Forms watertight seal b/n cells
Plasma membranes fused with strip of proteins
(great for cells that have water, ie: lumbar epithelial tissue in the lungs –> they need to be moist)
Common for cells in GI and bladder
Desmosomes
Resists cellular separation and cellular disruption
Intermediate filament cross into cytoplasm of cell (a stronger connection than dat tight pussy connection)
Cellular support for cardiac muscle (they all contract at same time repeatedly – they need v strong connection for the cells to stay together)
Superficial layers of skin
Hemidesmosomes
Half a desmosome
Connect cells to extracellular material (basal lamina)
(“hennidesmosomes” – that henny keeps u going thru life)
Gap junction
Tiny space between plasma membranes of two cells
Cross by protein channels (connexons) forming fluid filled tunnels
Cell communication with ions and small molecules
Impulse spread from cell to cell (common in epithelial cells, heart, and smooth muscle of gut)
Ions passing thru gap junctions help for many cells to signal simultaneously, esp. important in areas with no or limited blood supply
What are two types of normal tissue growth?
Hyperplasia and hypertrophy
Hyperplasia
Tissue growth for cell multiplication (cell division)
Hypertrophy
Enlargement of preexisting cells (ie: muscles grow via exercise)
Neoplasia
Growth of a tumor (benign or malignant) through growth of abnormal tissue
May arise if cell division and cell death eq. is disturbed
What are ways tissues can shrink?
Atrophy, necrosis, and apoptosis
Atrophy
shrinkage of tissue from loss of cell size/number
Senile atrophy: when you get old, everything shrinks and your body doesn’t restore it
Disuse atrophy: me every summer when I have nothing to do
Necrosis
Pathological death of tissue
Gangrene
Due to insufficient blood supply
Gas Gangrene
Bacterial infection that causes necrosis
Decubitus Ulcer
Bed sore or pressure sore (feel that every summer too)