Download Levels of Structural Organization within the Human Body

p. 5 (top) Essential Question #1
How is the human body organized?
• Levels of Organization:
– Cell
– Tissue (4 types)
– Organs
– Organ systems (we will learn 8)
– Human organism
Levels of Structural Organization
within the Human Body
The human body is divided into specific levels
of organization, and these levels are what
make the human body a complex organism.
Levels of Organization
Cells
Tissues
Organs
Organ System
Organism
Cells
• Basic units of structure and function within
the human body.
• All cells both perform the processes that keep
humans alive and have specialized functions.
Ex: nerve cells (neurons), blood cells, and bone
cells.
Tissues
• A group of specialized cells that work together to
perform the same function.
– Nerve tissue—carries impulses back and forth to the
brain from the body
– Muscle tissue (3 types: cardiac, smooth, skeletal)—
contracts and shortens, making body parts move
– Epithelial tissue—covers the surfaces of the body,
inside (as lining and/or covering of internal organs)
and outside (as layer of skin)
– Connective tissue—connects all parts of the body and
provides support (for example tendons, ligaments,
cartilage—blood, bone, and fat are also connective)
Organs
• A group of two or more different types of
tissue that work together to perform a specific
function.
Ex: The heart is made of muscle and connective
tissues which function to pump blood
throughout the body.
Body Systems
• A group of two or more organs that work
together to perform a specific function.
• Each organ system has its own function but
the systems work together and depend on one
another.
• Ex: circulatory, digestive, excretory (urinary),
integumentary (skin), muscular, nervous,
respiratory, and skeletal.
Body Systems with Organ Examples
1. Integumentary: skin
2. Muscular: biceps, gluteus maximus,
abdominals
3. Skeletal: skull, femur, humerus
4. Nervous: brain, spinal cord, peripheral nerves
5. Circulatory: heart, arteries, veins, capillaries
6. Digestive: mouth, stomach, small and large
intestines
7. Respiratory: mouth, nose, lungs
8. Excretory (urinary): urinary bladder, ureters,
urethra
Human Organism
• Body systems interact with each other and
with the environment outside the body to
keep the whole person healthy.