organism hierarchy cell --> tissues --> organs --> organ system --> organism
 tissue  composed of specialized cells of one type that perform a common function in the body
  homeostasis  The ability or tendency of an organism or cell to maintain internal equilibrium by adjusting its physiological processes.

negative feedback is when change is minimized

positive feedback is when change is maximized
 

 4 basic tissue types  epithelial, connective, muscular, nervous
 epithelial tissue  covers body surfaces and organs and lines body cavities; avascular, must get nutrients from underlying connective tissue; primary component of glands
 epithelial tissue classifications  shape: squamous (squished), cuboidal (cube), columnar (column)

 layers: simple (single), stratified (more than one)

  simple squamous  areas where secretion, absorption, and filtration occur
 stratified squamous  protection
 simple cuboidal  often glands
 simple columnar  often modified, e.g., lining digestive organs and includes microvilli (small protrusions)
 glands  one or more cells that produce and secrete a product
 gland classification  exocrine: glands with ducts that secrete their product onto the outer surface or into a cavity; e.g., digestive enzymes or sweat

 endocrine: glands that secrete their products (hormones) internally so they are transported by bloodstream

 cell junctions  tight junction: forms an impermeable barrier; prevents movement of substances past these joined cells

 gap junction:  channel between two adjacent cells; allows ions, sugars, and small molecules to pass between cells...coordination

adhesion junction : extracellular filaments attaching adjacent cell's cytoskeletons, allows movement of substances past cells & gives flexibility;  attaches cells to basement membrane (non-cellular protein layer between epithelium and connective tissue)

What is the hierarchy of structure starting with cells and ending with the organism?

What is homeostasis?  When a person becomes hot, they sweat.  Is this an example of negative or positive feedback?  During childbirth, mechanisms in the woman's body increase the opening of her cervix.  Is this an example of negative or positive feedback?

What is the definition of tissues?

What are the 4 types of tissue?

Where do you find epithelial tissue?  What are some to this tissue's functions?

What are the 3 basic shapes of epithelium?  What do each look like?

What does it mean when we say epithelial tissue is simple or stratified?

What is the basement membrane made of?  Is it living?  What is its role?

Is epithelial tissue vascular or avascular?  Where is its blood supply?

Skin is made up of what epithelial tissue?

Which shape of epithelial tissue is most closely related to glands? 

If you needed to have a high degree of exchange such as in the lungs, you would expect to find what type of epithelium?

Glands are classified how?  Exocrine glands secrete what and how?  Endocrine glands?  Hormones are associated with which type of gland?

If you were expecting to find a high degree of flexibility between cells, you would expect to find what type of junctions?

If you were expecting to find a high degree of control over movement of substance thru intercellular spaces, you would expect to find what type of junctions?

If you were expecting to find a strong coordination of information among neighboring cells, you would expect to find what type of junctions?  What moves through gap junctions?