answers
Define tissue Ans✓✓-group of structurally/functionally related cells and their
external environment that together perform common functions
List the four main tissue types Ans✓✓-epithelial, connective, muscle, nervous
Define Epithelial Tissue Ans✓✓-sheets of cells tightly packed together with little
visible ECM
cover/line all body surfaces/cavities
specialized cells form glands
Define Connective Tissue Ans✓✓-connects all other tissues in the body together
ECM most prominent feature; cells scattered throughout
bind, support, protect, allow transport
Define Muscle Tissue Ans✓✓-contract and generate force, little ECM
Define Nervous Tissue Ans✓✓-unique ECM; cells generate/send/receive
messages
Describe the two major components of the extracellular matrix Ans✓✓-Ground
Substance: shapeless, gel-like; contains interstitial/extracellular fluids with water,
ions, nutrients, and other solutes
Protein Fibers: multiple fibrous proteins subunits that entwine to form a long,
rope-like structure with great tensile strength
, Define Collagen Fibers Ans✓✓-composed of multiple subunits of a fibrous
protein, resistant to tension (tendons)
Define Elastic Fibers Ans✓✓-can stretch a lot and return to regular shape
Define Reticular Fibers Ans✓✓-thinner/shorter and interweave to form
meshwork that supports cells and ground substance. Forming webs in certain
organs to trap foreign cells
List the three different large molecules found in ground substance Ans✓✓-
Glycosaminoglycans
Proteoglycans
Glycoproteins
Define Tight Junctions and give an example Ans✓✓-holds cells tightly together
making space between impermeable (some leak) - between cells of blood vessels
preventing substance from leaving the blood
Define Desmosomes and give an example Ans✓✓-act like buttons, ECF can pass;
strengthens tissues by mechanical stress that is evenly distributed - epithelia of
the skin
Define Gap Junctions and give an example Ans✓✓-small pores in adjacent plasma
membranes formed by protein channels, allow small substance to pass freely
between cytosol of two cells - communicate with electrical signals (cardiac
muscle)