Chemical > Cellular > Tissue > Organ > System > Organism (the body)
chemical level
The chemical level is the most basic level of structural organization.
Atom
chemical elements that makes up the human body- in the chemical level , Oxygen,
carbon, hydrogen, and nitrogen make up 96% of the body's mass.
Molecule
A group of atoms bonded together - in the chemical level
cellular level
The sum of the chemical reactions in a cell makes up its structure and function.
Organelles
A tiny cell structure that carries out a specific function within the cell
tissue level
Groups of cells form tissues
There are four basic types of tissue grouped together by common features of
structure and function
epithelial tissue
connective tissue
muscular tissue
nervous tissue
The function of tissue is influenced by
by its constituent cells but also by the material and connections inside and outside of
the cell.
organ level
Organs are made up of different types of tissues
system level
related organs with a common function
, · organism level
Any living thing, and is made up of 11 body systems.
integumentary system
Consists of the skin, mucous membranes, hair, and nail
integumentary system functions
Protects the body from the external environment, excretes metabolic waste, helps to
make vitamin D, and detects pain, touch, dehydration, and changes in temperature.
Skeletal System
the skeletal system consists of the bones and the cartilage associated with joints.
skeletal system functions
Protects the body, provides support and a framework for muscles to act upon, contains
bone marrow for blood cells to develop in, and stores minerals such as calcium.
Muscular System
The muscular system consists primarily of skeletal muscle, but there are also two other
types of muscle: cardiac muscle found in the heart and smooth muscle found within
the viscera, including the alimentary canal and the walls of blood vessels.
Muscular system function
Enables the body to move by the action of opposing muscular contraction and
relaxation. It also maintains posture and plays a role in thermoregulation.
cardiac muscle
an involuntary, striated muscle that makes up the walls of the heart
smooth muscle
a muscle found in viscera
Nervous System
The nervous system includes the brain, spinal cord, nerves, and special sense organs
(e.g., eyes, ears, and taste buds). This system is divided into the central nervous
system, containing the brain and spinal cord, and the peripheral nervous system,
containing everything else.
nervous system functions
The functionality of the nervous system can be split into three main stages:
Detecting changes in the internal and external environment, encoding them into