ANIMAL TISSUES Copyright © 2009 Pearson Education, Inc.

ANIMAL TISSUES

Copyright © 2009 Pearson Education, Inc.

20.1 Structure fits function at all levels of organization in the animal body

Anatomy—structure

Physiology—function

Animals consist of a hierarchy of levels of organization


Cellular level: Muscle cellA

An example of structural hierarchy in a pelican

Tissue levelMuscle tissue

A BCellular levelMuscle cell


A B

CAn example of structural hierarchy in a pelican

Cellular levelMuscle cell


Organ levelHeart

A B

C

D


Organ system levelCirculatory system

Organ levelHeart



Organism levelMany organ systems functioning together

A B

C

D

E

Organ system levelCirculatory system

Organ levelHeart




20.2 EVOLUTION CONNECTION: An animal’s form reflects natural selection

• Sharks, seals, and penguins have streamlined, tapered bodies


Video: Galápagos Sea Lion

Video: Shark Eating a Seal

20.3 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

20.4 Epithelial tissue covers the body and lines its organs and cavities

• Epithelial cells come in three shapes:

1. Squamous—like a fried egg2. Cuboidal—as tall as they are wide3. Columnar—taller than they are wide


Apical surface ofepithelium

Cell nucleiUnderlying Tissue

Basallamina

Simple squamous epithelium(air sacs of the lung)

Simple cuboidal epithelium(kidney

Simple columnar epithelium(intestine

Stratified squamous epithelium(esophagus

Pseudostratified ciliated columnar Epithelium (respiratory tract)

A

B

C

D

E

Types of epithelial tissue

• Stratified epithelial cells are stacked on top of each other


20.4 Epithelial tissue covers the body and lines its organs and cavities

E

Types of epithelial tissue;Stratified squamus epithelium(lining the esophagus) Stratified squamous epithelium

(esophagus

20.5 Connective tissue binds and supports other tissues

• Connective tissue can be grouped into six major types


Fat droplets

Adipose tissue

White bloodCells

Red bloodcell

Blood

Plasma

Loose connective tissue(under the skin)

Elastic fibers

Collagen fiber

CellFibrousconnective tissue

(forming a tendon

Collagen fibers

Cell nucleusCartilage

(at the end of a bone)

Matrix

Cartilage-Forming cells

CentralCanal

Matrix

Bone-Forming Cells

Bone

B

AF

E

D

C

Types of connective tissue

20.6 Muscle tissue functions in movement

• Skeletal muscle: causes voluntary movements.

• Cardiac muscle: pumps blood.

• Smooth muscle: moves walls of internal organs, such as the intestines.


Unit of musclecontraction

Nucleus

Nucleus

Junction betweentwo cells

Nucleus

Muscle fiberCardiac muscle

Skeletal muscle

C

B

A

The three types of muscle

Muscle fiberMuscle fiber

20.7 Nervous tissue forms a communication network

• Neurons carry signals by conducting electrical impulses.

• Supporting cells insulate axons and nourish neurons


Cell body

Nucleus

Neurons in the spinal cord

20.8 Organs are made up of tissues

• Each tissue performs specific functions.

• The heart has epithelial, connective, and nervous tissues:

1. Epithelia line the heart chambers2. Connective tissues make the heart

elastic3. Neurons regulate contractions


Small intestine

Lumen

Epithelial tissue

Connective tissue

Smooth muscle tissue2Layers

Connective tissue

Epithelial tissue(columnar epithelium

Lumen

Tissue layers of the small intestine wall

• Artificial skin: Used to heal burn

20.9 CONNECTION: Bioengineers are learning toproduce tissues and organs for transplants


laboratory-grown bladder

PLANT TISSUES



31.5 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:– Bulk of the plant body– Food production, storage, support



• Dermal tissue:– Layer of tightly packed cells called the

epidermis.

– First line of defense against damage and infection

– Waxy layer called cuticle on top of epidermis, reduces water loss



1. Vascular tissue:– Composed of xylem and phloem– Arranged in bundles

2. Ground tissue:– Lies between dermal and vascular tissue– Eudicot stem ground tissue is divided into pith and cortex– Leaf ground tissue is called mesophyll

Eudicot leaf

Xylem Phloem

ا

Vein

GuardCells

StomaSheath

Eudicot stemVascular

bundle

Pith

Cortex

Epidermis

Eudicot root

Endodermis

Cortex

Epidermis

Phloem

Xylem

cylinder

Mesophyll

Cuticle

Upper epidermisا

Lower epidermis

Monocot stemVascularBundle

Epidermis

Key

Ground tissue systemDermal tissue system

Vascular tissue system

The three plant tissue systems

Eudicot leaf

XylemPhloem

Vein

GuardCells

Stoma

Sheath

Mesophyll

Cuticle

Upper epidermis

Lower epidermis

Key

Ground tissue system

Dermal tissue system



Eudicot stemVascularbundle

Pith

Cortex

Epidermis

Monocot stemVascularBundle

Epidermis

Key





Eudicot root

Endodermis

Cortex

Epidermis

Phloem

XylemVascularcylinder

Key







• Plants cells have three structures that distinguish them from animals cells:

1. Chloroplasts used in photosynthesis2. A large, fluid-filled vacuole3. A cell wall composed of cellulose


31.6 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

Pit

Plasmodesmata

Plasmamembrane

Cell walls ofadjoining cells

Secondarycell wall Middle lamella

Cell wallsPrimary cell wall

Central vacuole

ChloroplastNucleus

Endoplasmicreticulum

Mitochondrion

Golgiapparatus

Ribosomes

Microtubules

Plasma membrane

The structure of a plant cell


• Plant cell structure is related to function.

• There are five major types of plant cells:1. Parenchyma cells2. Collenchyma cells3. Sclerenchyma cells4. Water-conducting cells5. Food-conducting cells




• Parenchyma cells:

– The most abundant cell type– Have thin primary cell wall– Lack secondary cell wall– A live at maturity– Function in photosynthesis, food and

water storage

Starch-storing vesicles

Primarycell wall

(thin)

Pit

Parenchyma cell


• Collenchyma cells:

– Have unevenly thickened primary cell wall

– Lack secondary cell wall– A live at maturity– Provide flexible support


Primarycell wall(thick)

Collenchyma cell


• Sclerenchyma cells:

– Have thick secondary cell wall that contain lignin, (lignin is a main component of wood(

– It is dead at maturity– Rigid support– There are two types of sclerenchyma

cells: fibers and sclereids.

– Fibers—long and thin, arranged in bundles.

– Sclereids—shorter than fibers, present in nut shells and pear tissue.


Primarycell wall

Sclereid

Pits

Secondarycell wall

Sclereid cells

Secondarycell wall

Pits

Primarycell wall

Fiber

Fiber cells

Sclerenchyma cells:fiber (left) and sclereid (right)

Secondarycell wall

Pits

Primarycell wall

Fiber

Fiber cells

Sclerenchyma cells: fiber

Primarycell wall

Sclereid

Pits

Secondarycell wall

Sclereid cells

Sclerenchyma cells: sclereid (right)


• Water conducting cells: tracheids and vessel elements:

– 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


Pits

Pits Tracheids

Vessel element

Openingsin end wall

Water-conducting cells


• Food-conducting cells: Sieve tube members:

– No secondary cell wall– A live 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


Cytoplasm

Primarycell wall

Companion cell

Sieve plate

Food-conducting cell (sieve-tube member)

Meristematic tissues: • These are located at the tips of roots and stems, between the

water- and food-conducting tissues of stems, and at various other places in plant bodies


Locations of apical meristems, which are responsible for primary growth

Axillary buds

Terminal bud

Root tips

Black Arrows = direction of growth

Cellulose fibers

Key




Apical meristemRegion

Zone of elongation

Zone of maturation

Zone of cell division

Root cap

Epidermis Cortex Vascular cylinder

Root hair

Primary growth of a root

• 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)


Microscopic photographs of the meristematic cells in the tip of onion roots showing cell division (Arrows)


ANIMAL TISSUES Copyright © 2009 Pearson Education, Inc.

Documents

nervous tissue slide

muscle tissue functions

tissues connective tissue

pelican slide

seal slide

organism level

smooth muscle

cardiac muscle