Exam 1 Part 3 Flashcards
Organs
aggregate of 2+ tissue types performing a specific function
System
aggregate of 2 or more organs performing a specific function
Organism
whole of the organ systems
Matrix
non-living, intercellular + extracelluar secreted by cells
Matrix can be
sold
semi-solid
liquid
fibrous
Categories of tissues
epithelial
connective
muscle
nervous
Differentiation
specialization of cells; genetic control
Once happens, cells usually cannot divide or change
Stem cells
cells not yet completely differentiated
can divide and become any type of cell
Epithelial tissue
covers surface and lines cavities
little matrix
Epithelial tissue functions
protection absorption filtration diffusion Regenerative secretion sensation
basement membrane
sheet-like barrier of extracellular material b/t ET and underlying CT - attaches 2 layers produced by both
intercellular junctions
tight
gap
desmosomes
tight junction
complete attachment bt cells -forms fused band around cells
-keeps things from passing across (digestive)
Desmosome
spot attachment -gives some connectiveness (skin)
Desmos
bond
gap junction
passageway for small particles to pass bt cells (cell membrane) nerve impulses
simple squamous ET
single layer, flattened, irregularly shaped, fragile
simple squamous ET function
diffusion
line blood vessels, heart chambers (endothelium)
line body cavities and organs (mesothelium)
Simple cuboidal ET
lines small ducts/tubes having secretory functions; may also be exretory or absorptive
–follicles of thyroid
Simple columnar ET
(protection), secretion, absorptive
digestive and repsiartory tract; portions of female reproductive system
may be associated with goblet cells (glands)
Secrete mucus
May have projections
Cilia
cell extentions
beat to move materials over surface
Usually on simple columnar ET
Microvilli
form brush border
villus- hair
Stratified epithelium
layers
worn away, replaced by mitosis in deepest layers
classifity by surface cell shape
Startified squamous ET
variable layers
2 types
