Tissues of the
Body
From Cells to Organ Systems
• Cells combine to form tissues, and
tissues combine to form organs
• Cells combine to form four primary
tissues
– Epithelial tissue
– Connective tissue
– Muscle tissue
– Nervous tissue
Epithelium
• Two types:
– membranes
• form the coverings or linings of organs
– glands
• form glands
Epithelial Tissue
(Covering)
• Tightly-joined closely-packed cells
• Covers the outside of the body and
lines the internal organs and cavities
• Barrier against mechanical injury,
invasive microorganisms, and fluid
loss
• Functions include protection,
secretion, absorption, excretion,
filtration, diffusion, and sensory
reception
Epithelial Tissue
Connective Tissue
• Binds the cells and organs of
the body together
– All connective tissues
consist of two basic
components: cells and
extracellular matrix (web
of fibers embedded in a
liquid, jelly, or solid)
– Store fat
– Transport substances
– Protect against disease
– Repair tissue damage
Section 4-1
Fig. 40-5h
Adipose tissue
Fat droplets
Function: stores
fat for insulation
and fuel
150 µm
Structure: cells
with large
storage vacuoles
Adipose tissue
Fig. 40-5f
Osteon
Structure: cells (osteocytes)
embedded in mineralized
(calcium phosphate) matrix
Function: Matured bone contains
about 65% mineralized matter,
the rest being collagen and
matrix. The mineral gives bone its
toughness and rigidity, the highly
ordered fibrous component
provides tensile strength and
flexibility.
700 µm
Bone
Central canal
Bone
Fig. 40-5i
White blood cells
Blood
Function: transport
nutrients, waste, oxygen,
carbon dioxide, fight
intruders
55 µm
Structure: composed of
blood cells and cell
fragments in blood
plasma (liquid matrix)
Plasma
Blood
Red blood
cells
Muscle Tissue
• Consists of specialized cells that contract when
stimulated
• The body has three types of muscle tissue:
• Skeletal (voluntary)
• Cardiac (involuntary)
• Smooth muscle (involuntary)
M
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s
c
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e
T
i
s
s
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e
Nervous Tissue
• Contains specialized cells
that conduct impulses
• Conducting cells, called
neurons, transmit
impulses from one region
of the body to another.
• Nonconducting cells,
neuroglia, are a type of
nervous system
connective tissue.
Nerve Tissue
Organ Systems
• Tissues combine to form organs.
– Organs are discrete structures that have evolved to
perform specific functions
– Most organs do not function alone, they are part of a
group of cooperative organs, called an organ
system.