Anatomy - levels of structural organization in the human body

Cell Theory

1) All life consists of cells 2) All cells come from per-existing cells.

name the 6 levels of structural organization of the human body

1. chemical level; 2. cellular level; 3. tissue level; 4. organ level; 5. system level; and 6. organismal level.

Four types of tissues

Connective tissue; epithelial tissue; muscular tissue; nervous tissue.

Connective Tissue

Most abundant animal tissue; four structural types: Connective tissue proper Cartilage Bone Blood

Epithelial Tissue

Rests on any naturally occurring free surface; has two forms: 1) covering/lining and 2) glandular

Muscular Tissue

Specialized for contractility; there are three types: Skeletal Smooth Cardiac

Nervous Tissue

Specialized for excitability: A neuron is the basic unit

PARENCHYMA

functional cells

chemical level

includes atoms organized into molecules; subatomic>atomic>molecular> macromolecular. (example: DNA, glucose, mitrochondria)

cellular level

molecules are organized into cells which are the basic structural and functional living units an organism; 60 trillion cells Protoplasmic compounds from organelles "little organs" (example: muscle cells, nerve cells, blood cells)

organ level

structures that have definitive form; structures that are composed of 2 or more different types of tissues, that have specific functions and usually have recognizable shapes (example: liver, stomach, heart, lungs, brain)

STROMA

supportive of functional cells

tissue level

Cells are organized into tissues to perform a particular function Groups of similarly specialized cells and their intracellular material. (example: epithelial, connective, muscle and nervous tissues)

organismal level

all the systems are structurally integrated and function cooperatively to constitute the total organism (example: the human body)

system level or organ-system level

consists of related organs with a common function; the number of systems of the body can be "lumped" or "split"; all systems of the human body working together provides for HOMEOSTASIS