Tissue Test Flashcards
tissue
collection of specialized cells and extracellular matrix that perform limited, specialized functions
histology
study of tissues
4 main tissue types
-epithelial -connective -muscle -nervous
epithelial
-lines the external surface of all organs -lines interior of all hollow organs -skin surface (epidermis) -makes up all glands
connective
-provide structure and support -provide transport
muscle
provides movement
nervous
-provides flow of information and control through electrical signaling
main functions of epithelium
-protection -absorption -filtration -secretion -sensation
protection (function of epithelium)
protects of all exposed and internal surfaces
control permeability (function of epithelium)
-different in different areas of the body -by absorption and filtration
provide sensation (function of epithelium)
through specialized epithelial cells
secrete and excrete (function of epithelium)
-through specialized gland cells -exocrine and endocrine
epithelial characteristics
-location -orientation -cellular arrangement -avascular -regenerate
location (epithelial characteristic)
-on all free body surfaces -outside of organs -lining cavities, chambers, and hollow membranes
orientation (epithelial characteristic)
-all have an apical part of a membrane -attatched to a basal surface or basement membrane connecting it to the underlying connective tissue
cellular arrangment (epithelial characteristic)
-cells arranged in close proximity and often attached in sheets -little to no matrix
avascular (epithelial characteristic)
no direct connection to the vascular system (rely on adjacent tissue for nutritient)
regenerate (epithelial characteristic)
constantly regenerated due to presence of specialized stem cells
classification of epithelia
-layers -shape
layers (classification of epithelia)
-simple -stratified -pseudostratified -transitional
shape (classification of epithelia)
-squamos -cuboidal -columnar
simple squamos
-diffusion and rapid filtration -secretion in serous membranes
simple cuboidal
-secretion and absorption -ciliated types propel mucus or reproductive cells -covers surface of ovaries
simple columnar
-secretion and regulated slower absorption -ciliated types propel mucus or reproductive cells -lines entire digestive system from stomach through large intestine (forms a mucosa membrane) -goblet cells dispersed throughout
simple transitional
doesn’t exist
stratified squamos
-protection -found where mechanical stress is high
stratified cuboidal/columnar
-protection -rare -found in ducts of very large glands
stratified transitional
-protection -stretches to accomodate disension of urinary structures -only epithelial tissue to have more than 3-4 layers (in a resting state) -specialized squamos
pseudostratified columnar
-all cells on the basement membrane but vary in height (nuclei appear at different heights) -secretion and regulated slower absorption -lines respiratory tree (forming a mucosa) -goblet cells dispersed throughout -apical cilia provide movement of mucus
pseudostratified columnar
-all cells on the basement membrane but vary in height (nuclei appear at different heights) -secretion and regulated slower absorption -lines respiratory tree (forming a mucosa) -goblet cells dispersed throughout -apical cilia provide movement of mucus
types of glandular epithelia
-endocrine -exocrine
endocrine
-secretions released to surrounding tissue and blood -ductless -ex: hormones