Transcript Cellular Organization

Cellular Organization
FIVE LEVELS OF ORGANIZATION
7-3.1 SUMMARIZE THE LEVELS OF
STRUCTURAL ORGANIZATION
WITHIN THE HUMAN BODY.
Levels of Organization
• From smallest to largest:
Cells
Tissues
Organs
Organ systems
Organism
Cells
 Cell – basic unit of structure and function in living
things.
 Cells make up all living things.
The Benefits of Being Multicellular
 Larger size
 The larger you are, the less predators you have, and you can
eat larger prey!
 Longer life
 Longer life-span than unicellular organisms.
 Specialization
 Each type of cell has a particular job.
 This makes the organism more efficient.
Tissues
 Tissue – group of similar cells that perform the
same function.
 Most animals (including humans) have four basic
types of tissue:
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Muscle tissue
Nerve tissue
Connective tissue
Protective tissue
Muscle Tissue
 Muscle tissue – makes parts of your body move by
contracting (shortening) and relaxing.
 In some cases, like throwing a ball, you control the
movement.
 In other cases, such as the beating of your heart, the
movement occurs without conscious control.
Nerve Tissue
 Nerve tissue – carries messages back and forth
between the brain and every other part of the body.
Connective Tissue
 Connective Tissue – provides support for your body
and connects all its parts.

Ex:
Bone – supports & protects
 Fat – insulation & energy storage
 Blood
 Tendons
 Ligaments
 cartilage

Epithelial Tissue
 Functions as a boundry.
 Covers the surfaces of the body, inside (as lining/or
covering of internal organs) and outside of the body.
Organs
 Organ – structure composed of
two or more different types of
tissue that work together for a
specific function.
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Each organ performs a specific job.
Ex:
Heart – pumps blood throughout the
body
 Stomach – breaks down food so that it
can be absorbed by the intestines.

Organ Systems
 Organ system – a group of two ore more organs
that work together to perform a specific job.
 Ex:

Circulatory system – heart, blood vessels, blood
There are 11 different organ systems in the human body.
Circulatory, digestive, endocrine, excretory, immune,
integumentary (skin), muscular, nervous, reproductive,
respiratory, and skeletal.
Organism
 Organism - a living thing
Structure & Function
 Structure - the arrangement of parts in an
organism

Includes the shape of a part and the material from which it is
made.
 Function - the job the part does
 Ex: structure of lungs (spongy sac) is related to its function
Homeostasis
 The different organ systems work together and
depend on one another.
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Ex:

Respiratory, digestive & circulatory systems work together to fuel
muscles with the energy they need.
 The systems of the human body work together to
maintain homeostasis.
 Your body is constantly regulating internal
conditions.

Blood sugar, posture, temperature.