Anatomic Levels of Organization

atom

atom

tiny particles that make up everything

molecule

different atoms chemically joined together

macromolecule

large bio particles made from molecules (DNA, protein)

organelle

structure that can perform a specific function (mitochondrion = supplies energy)

cell

basic unit of functioning life (muscle, nerve, or blood cell)

tissue

layer or mass of cells that perform a specific ability (adipose tissue)

organ

complex structures with specialized functions composed of a collection of tissues (heart, kidney, stomach)

organ system

group of organs that work with each other to perform a specific purpose (digestive system)

organism

individual composed of multiple interacting organ systems (human)

cranial cavity

skull and houses brain

vertebral cavity

contains the spinal cord within the vertebrae

cavities that contain soft organs called viscera

thoracic cavity and abdominopelvic cavity

pleural cavity

lungs

pericardial cavity

heart

superior mediastinum

esophagus, trachea, and thymus gland

visceral layer

inner layer that covers an organ

parietal layer

outer layer attached to the wall of the cavity

visceral and parietal pluera

surrounds lungs

visceral and parietal pericardium

surrounds the heart

visceral and parietal peritoneum

surrounds the abdominopelvic organs

serous membrane

smooth tissue sac that is filled with serious fluid preventing friction between the two layers