Levels of Structural Organization Flashcards
Chemical level
Simplest level of the structural hierarchy; atoms, tiny building blocks of matter, combine to form molecules
Molecules
Molecules, such as water and proteins, associate in specific ways to form organelles
Organelles
Basic components of the microscopic cells
Cells
The smallest units of living things; all cells have some common functions, but individual cells vary widely in size and shape, reflecting their unique functions in the body
Levels of Structural organization
Chemical, cellular, tissue, organ, organ system, organismal
Tissue level
Tissues consists of similar types of cells
Tissues
Groups of similar cells that have a common function
4 Basic tissue types
Epithelium, muscle, connective tissue, & nervous tissue
Epithelium
Covers the body surface and lines its cavities
Muscle
Provides movement
Connective tissue
Supports and protects body organs
Nervous tissue
Provides a means of rapid internal communication by transmitting electrical pulses
Organ
A discrete structure composed of at least two tissue types (4 is more common) that performs a specific function for the body; a specialized functional center responsible for a necessary activity that no other organ can perform
Organ level
Extremely complex functions become possible here
Organ system level
Organs that work together to accomplish a common purpose (e.g. the heart and blood vessels of the cardiovascular system circulate blood continuously to carry oxygen and nutrient to all body cells)
