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Chapter 5
Tissues
ANIMAL TISSUES
Copyright © 2009 Pearson Education, Inc.
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Tissue
• A group of similarly specialized cells
• Associated to perform one or more
functions
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A
Cellular level
Muscle cell
An example of structural hierarchy in a pelican
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A
B
Cellular level
Muscle cell
Tissue level
Muscle tissue
An example of structural hierarchy in a pelican
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A
B
Cellular level
Muscle cell
Tissue level
Muscle tissue
C
Organ level
Heart
An example of structural hierarchy in a pelican
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A
B
Cellular level
Muscle cell
Tissue level
Muscle tissue
C
Organ level
Heart
Organ system level
Circulatory system
D
An example of structural hierarchy in a pelican
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A
B
Tissue level
Muscle tissue
Cellular level
Muscle cell
C
Organ level
Heart
Organ system level
Circulatory system
D
E
Organism level
Many organ systems functioning together
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Structure fits function
Animals consist of a hierarchy of levels of
organization
Structure fits function at all levels of
organization in the animal body
Copyright © 2009 Pearson Education, Inc.
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Tissues are groups of cells with a common structure
and function
 Animals have four main categories of tissues
1) Epithelial tissue
2) Connective tissue
3) Muscle tissue
4) Nervous tissue
Copyright © 2009 Pearson Education, Inc.
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1. Epithelial Tissue (Epithelium)
• A continuous layer (sheet) of cells
– covering a body surface
– lining a body organs and cavity
• Functions in protection, absorption,
secretion, or sensation
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Epithelial tissue
• Epithelial cells come in three shapes
– Squamous — like a fried egg
– Cuboidal — as tall as they are wide
– Columnar — taller than they are wide
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Apical surface of
epithelium
Basal
lamina
Underlying Tissue
A
Cell nuclei
D Pseudostratified
Simple squamous epithelium
ciliated columnar
Epithelium
(respiratory tract)
B Simple cuboidal epithelium
(kidney )
Types of epithelial tissue
E Stratified squamous epithelium
C Simple columnar epithelium
(intestine )
(esophagus)
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Epithelial tissue covers the body and lines its
organs and cavities
• Stratified epithelial cells
are stacked on top of
each other
Stratified squamous epithelium
(esophagus)
Types of epithelial tissue;
Stratified squamus
epithelium
(lining the esophagus)
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Connective Tissues
• Cells embedded in intercellular substance
– Microscopic collagen fibers, elastic fibers,
reticular fibers (thin branched fibers)
– Scattered through a matrix (thin gel of
polysaccharides)
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Connective tissue
• Connective tissue can be grouped into six major
types
1. Loose connective tissue (under the skin)
2. Fibrous connective tissue (forming a tendon )
3. Adipose tissue
4. Cartilage (at the end of a bone
5. Bone - Bone-Forming Cells
6. Blood
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Fat droplets
CartilageForming cells
C Adipose tissue
Matrix
Cell nucleus
D Cartilage
(at the end of a bone(
Central
Canal
Collagen fibers
Cell
B Fibrous connective
tissue
(forming a tendon )
Collagen fiber
Matrix
White blood
Cells
Red blood
cell
E Bone
Elastic fibers
Bone-Forming Cells
A Loose connective tissue
(under the skin)
Plasma
F Blood
Types of connective tissue
Muscle tissues; function in movement
A. Skeletal muscle causes voluntary
movements. Striated and under voluntary
control, move parts of the body
B. Smooth muscle moves walls of internal
organs, such as the intestines. No
striations, contractions involuntary
C. Cardiac muscle pumps blood. Striated,
contractions are involuntary. Muscle
contracts, heart pumps blood
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Unit of muscle
contraction
Muscle fiber
Junction between
two cells
Muscle fiber
Nucleus
Nucleus
Muscle fiber
Nucleus
B Cardiac muscle
A Skeletal muscle
C Smooth muscle
The three types of muscle
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Nervous tissue )Neuron cells)
• Neurons
− Carry signals by conducting electrical
impulses
− Elongated cells
− Receives and transmits information
• Synapse
− A junction between neurons
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Neuron
• Dendrites (from Greek déndron, "tree")
− Receive signals
– Transmit signals to cell body
• Axon (from Greek, “axis") also known as a nerve fibre)
– Transmits signals away from cell body to
other neurons, muscles, glands …..
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Cell body
Neurons
Dendrites
Nucleus
Axon
Neurons in the spinal cord
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Organs are made up of tissues
• Each tissue performs specific functions
• The heart has epithelial, connective, and
nervous tissues
– Epithelia line the heart chambers
– Connective tissues make the heart elastic
– Neurons regulate contractions
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Small intestine
Lumen
Tissue layers of the
small intestine wall
Lumen
Epithelial tissue
(columnar epithelium )
Connective tissue
Smooth muscle tissue
(2 layers )
Connective tissue
Epithelial tissue
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PLANT TISSUES
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Three tissue systems make up the plant body
1) Dermal tissue
 Outer protective covering
2) Vascular tissue
 Support and long-distance transport
3) Ground tissue
 The bulk of the plant body
 Food production, storage & support
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1. Dermal tissue
• Dermal tissue
 Layer of tightly packed cells called the
epidermis
 First line of defense against damage and
infection
 Waxy layer called cuticle, lies on the top of
epidermis, and reduces water loss.
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Three tissue systems make up the plant body
2. Vascular tissue
– Composed of xylem and phloem
– Arranged in bundles
3. Ground tissue
– Lies between dermal and vascular tissue
– In Eudicot stem ground tissue is divided
into pith and cortex
– Leaf ground tissue is called mesophyll
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Eudicot leaf
Cuticle
Xylem
Upper epidermis
Vein
Phloem
Mesophyll
Guard
Cells
The three plant
tissue systems
Lower epidermis
Stoma
Sheath
Eudicot stem
Monocot stem
Vascular
bundle
Cortex
Vascular
Bundle
Pith
Epidermis
Epidermis
Xylem
Phloem
Vascular
cylinder
Epidermis
Cortex
Key
Dermal tissue system
Ground tissue system
Vascular tissue system
Endodermis
Eudicot root
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Key
Dermal tissue system
Ground tissue system
Vascular tissue system
Eudicot leaf
Vein
Cuticle
Upper epidermis
Xylem
Phloem
Mesophyll
Guard
Cells
Lower epidermis
Stoma
Sheath
The three plant tissue systems
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Key
Dermal tissue system
Ground tissue system
Vascular tissue system
Eudicot stem
Vascular
bundle
Monocot stem
Vascular
Bundle
Cortex
Pith
Epidermis
Epidermis
The three plant tissue systems
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Xylem
Phloem
Vascular
cylinder
Epidermis
Cortex
Key
Dermal tissue system
Ground tissue system
Vascular tissue system
Endodermis
Eudicot root
The three plant tissue systems
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Structures that distinguish Plant cells from
animal cells
• Plant cells have three structures that distinguish them
from animal cells
1) Chloroplasts used in photosynthesis
2) A large, fluid-filled vacuole
3) A cell wall composed of cellulose
Chloroplast
Central vacuole
Primary cell wall
2ry cell wall Middle lamella
The structure of a plant cell
Cell walls of
adjoining cells
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Plant cells and tissues are diverse in
structure and function
• Plant cell wall
 Some plant cell walls have two layers
– Primary cell wall — outermost layer
– Secondary cell wall — tough layer inside
primary wall
 A sticky layer called the middle lamella lies
between adjacent plant cells
 Openings in cell walls called plasmodesmata
allow cells to communicate and exchange
materials easily
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Nucleus
Chloroplast
Central
vacuole
Cell walls
Endoplasmic
reticulum
Primary cell wall
Secondary
cell wall
Mitochondrion
Golgi
apparatus
Middle lamella
Cell walls of
adjoining cells
Ribosomes
Plasma
membrane
Microtubules
Plasmodesmata
Plasma membrane
Pit
The structure of a plant cell
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Plant cells and tissues
• Plant cell structure is related to function
• There are five major types of plant cells
– Parenchyma cells making
parenchyma tissue
– Collenchyma cells making
collenchyma tissue
– Sclerenchyma cells making
sclerenchyma tissue
– Water-conducting cells making xylem tissue
– Food-conducting cells making phloem tissue
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Plant Tissue Systems
1. Ground Tissue System consists of 3 tissues,
 Parenchyma tissue
 Collenchyma tissue
 Sclerenchyma tissue
2. Vascular Tissue System consists of 2 tissues
 Xylem tissue
 Phloem tissue
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Parenchyma Tissue
 Composed of living parenchyma cells
 Most abundant cell type
 Thin primary cell wall
 Lack secondary cell wall
 Alive at maturity
 Function in photosynthesis, food and water storage
Primary cell wall
(thin)
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Primary cell wall
(thin)
Pit
Starch-storing vesicles
Parenchyma cell
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Collenchyma Tissue
 Consists of collenchyma cells
 Collenchyma cells
 Unevenly thickened primary cell wall
 Lack secondary cell wall
 Alive at maturity
 Provide flexible support
Primary
cell wall
(thick)
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Sclerenchyma Tissueells
 Composed of Sclerenchyma cells
– Thick secondary cell wall containing lignin, (lignin
is a main component of wood(
– Dead at maturity
– Rigid support
– Two types of sclerenchyma cells are fibers and
sclereids
– Fibers — long and thin, arranged in bundles
– Sclereids — shorter than fibers, present in nut
shells and pear tissue
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Pits
Sclerenchyma cells:
fiber
Secondary
cell wall
Fiber cells
Primary
cell wall
Sclereid cells
Fiber
Secondary
cell wall
Sclerenchyma cells:
sclereid
Primary
cell wall
Pits
Sclereid
Xylem tissues
 Water conducting cells - tracheids and vessel
elements, conduct water and dissolved minerals
– Both have thick secondary cell walls
– Both are dead at maturity
– Chains of tracheids and vessel elements form
tubes that make up the vascular tissue called
xylem conducts water and dissolved minerals
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Pits
Tracheids
Vessel element
Openings
in end wall
Pits
Water-conducting cells
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Phloem tissues
 Food-conducting cells — sieve tube members
– No secondary cell wall
– Alive at maturity but lack most organelles
– Companion cells
• Contain organelles
• Control operations of sieve tube members
– Chains of sieve tube members, separated by
porous sieve plates, form the vascular tissue
called phloem, conducts sugar in solution
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Sieve plate
Companion cell
Primary
cell wall
Cytoplasm
Food-conducting cell (sieve-tube member)
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Vascular Tissue Cells
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Plant Meristematic tissues
Meristematic tissues
These are located at the tips of roots and
stems, between the water- and foodconducting tissues of stems, and at
various other places in plant bodies.
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Locations of apical
meristems, which are
responsible for primary
growth
Terminal bud
Axillary buds
Black Arrows = direction of growth
Root tips
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Vascular cylinder
Root
Cortex
Epidermis
Zone of maturation
Primary
growth of a
root
Zone of elongation
Cellulose fibers
Apical meristem
region
Zone of cell division
Key
Dermal tissue system
Ground tissue system
Root cap
Vascular tissue system
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Plant Meristematic tissues
 Meristematic cells are small, thin-walled,
frequently cubical, densely packed with
protoplasm, and capable of producing new
cells by cell-division.
 Permanent tissues do not become changed
into other kinds of tissues as do Meristematic
tissues.
 (Source of differentiation: they give rise to
all other kinds of tissues)
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Plant Meristematic tissues
Microscopic photographs of the meristematic cells in
the tip of onion roots showing cell division (Arrows)
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