Transcript Tissues, Organs, & Systems

Tissues, Organs, & Systems
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Definitions:
• TISSUE: groups of cells of a similar structure
which perform specialized functions (examples:
muscle tissue, connective tissue, bone tissue)
• ORGANS: groups of similar tissues organized
into recognizable units (examples: heart, kidney,
liver)
• SYSTEMS: a collection of tissues & organs that
work together to perform a specific & uniformed
function (examples: digestive system, nervous
system, circulatory system)
EPITHELIUM – THE COVERING TISSUE
• cells may be thin & flat,
tall & columnar, or any
shape in between
• may be a single layer or
up to several layers of
cells
• functions of a covering &
lining tissue
Function of Epithelium
• covers the exposed surfaces of the body –
the skin, the eyes, the lips
• lines the cavities, tracts, vessels, & ducts in
the interior of the body (lines the digestive
tract, the blood vessels, the abdominal &
chest cavities, the ducts of glands, as well as
making up the secretory cells of glands)
CONNECTIVE & SUPPORTING TISSUE
• These tissues are
characterized by the
large amount of
extracellular, or
nonliving, materials
they contain.
– Connective tissue
– Bones & cartilage tissue
– Fat tissue
Connective Tissue
• composed mainly of the protein collagen
– Overlapping tissues form a fabric-like
consistency that is very tough and durable
– Elastic fibers within tissue make it very flexible
and elastic
– Binds cells to cells, cells to tissues, tissues to
organs, and just about everything else!
Bone & Cartilage Tissue
• Living tissue composed of calcium and
phosphorus compounds
• Rigid, strong, and tough
FAT TISSUE
• Composed of
specialized cells that
each take up & store
fat as a single globule
within the interior of
each cell
– Found under skin;
much of it is found in
& about internal organs
Muscle – The Contracting Tissue
•
•
•
Striated muscle
–
Moves the body parts
–
Composed of bundles of long, thin, cylindrical fibers arranged
parallel to one another
–
A.K.A skeletal muscle
Smooth muscle
–
Found in the internal organs & blood vessels
–
Unstriated muscle
–
Long, spindle-shaped cells
Cardiac muscle
–
Found only in the heart
–
Cell size and shape is intermediate between striated and smooth
The Conducting Tissue
• Nerve cells (neurons)
– Three parts of nerve
cells are cell body,
dendrites, and axons