Architectural Pattern of an
animal
Chapter 9
What is an animal?
Levels of organization and organismal
complexity
• 5 major levels of
complexity
• Unicellular
• Metazoan?
• Tissue
• Organ
• Organ systems
Levels of organization and
organismal complexity
• Protoplasmic
– Found in unicellular
organisms
– Life functions are
confined to a single
cell
– Contains organelles
with specific functions
• Cellular
– Cell aggregations with
functional
differentiations
– Division of labor;
nutrition, reproduction
– Not yet tissues!
– Ex. volvox
Protoplasmic
• Euglena
• Paramecium
Levels of organization and
organismal complexity
• Cell-tissue
– Similar cells are found
in layers
– sponges/ jellyfish
– Contains organelles
with specific functions
– Ex. Cnidarian nerve
net ( functions in
coordination)
• Tissue-organ
– More than one tissue
type working together
to have a more
specialized function
– Flatworms
– Ex. Eyespots/
reproductive system
Cell-tissue
Jelly fish
Sponges
Tissue-organ
Three Basic Tissues
ectoderm
mesoderm
endoderm
muscle layers
mesoderm
epidermis
ectoderm
ciliated
epidermis
ectoderm
parenchyma
mesoderm
pharynx
nerve cord
ectoderm
gut
endoderm
Levels of organization and
organismal complexity
• Organ-system
– Organs work together
to perform some
function
– Organ systems
– Ex circulation,
respiration
– Most animal phyla
Organ Systems of an
Earthworm
Organ system
Organ system
pierce-&-suck carnivores - chelicera are poison fangs
Animal tissue types
• What is a tissue?
• A cooperative unit of many very similar
cells that perform a specific function.
• Examples
–
–
–
–
Epithelial
Connective
Muscle
Nervous
Epithelial tissue
• Covers and lines the body and its parts
• One surface free, the other bound to
basement membrane
• Tissues are named by
– Shape of cells
– Number of layers of cells
Epithelial
tissue Hickman
Fig 9.3
•
•
•
•
•
Simple= single layer
Stratified = multiple layers
Squamous = flat (tiles)
Cuboudal = like dice
Columnar = like bricks
Simple Squamous
Simple Cuboidal
In the kidney tubules
Hickman
Fig 9.4
Lines the lungs
Stratified Squamous Epithelium
Hickman
Fig 9.4
Lines the esophagus
Ciliated columnar epithelium
Hickman
Fig 9.5
Lines the air ways in the respiratory system
Connective tissue
• Binds other tissues an provides support
matrices
• Few cells in a nonliving matrix (ground
substance)
• Three fiber types
– Collagen fibers
– Elastic fibers
– Reticular fibers
• Fibroblasts - cells that produce connective
tissue
Loose connective tissue
(Areolar) Campbell
Fig 20.5A
Holds other tissue in place
A “binding” material
Other Connective tissues
Hickman
Fig 9.6
Loose
Fibrous connective
Adipose
Cartilage
Blood
Bone
Bone Tissue
• Osteocytes
• Haversian canal
• Lamelle (matrix)
Campbell
Fig 20.5D
Bone Development
Muscle tissue
• Functions in movement
• Bundles of long cells ( muscle fiber= muscle cell)
• Skeletal muscle
– Attached to bones by tendons, produces voluntary
movement
– Striated unbranched
• Smooth muscle
– Found in walls of digestive tract, produces involuntary
movements
– Unstriated, spindle shaped
• Cardiac Muscle
– Striated , branched, produces heartbeat
Muscle tissue
Campbell 20.6
Cardiac
muscle
Skeletal
muscle
Smooth
muscle
Nervous Tissue
• Responsible for coordinating body activties
• Neurons are nerve cells
• Motor neurons are nerves that activate
muscles
• Compsed of cell body and dendrites
• Supported by glial cells
Hickman
Fig 9.8
Nervous Tissue
Hickman
Fig 9.8
Types of animal symmetry
• Radial
• Bilateral
• Apparent bilateral
Apparent Radial Symmetry
compare Hickman Fig. 9-10
like spokes of a
wheel
sea star
Bilateral symmetry
• cephalized
– sensory organs concentrated in head
• body directions:
Radial symmetry
• Radial symmetry– Mirror images around
a central axis
– Figure 9.10
Body Cavities
• Groupings according to presence or type of
body cavity
• Coelom - major innovation in bilaterally
symmetric animals
• Tube within a tube arrangement
Body Cavities
• Advantages
• Flexibility for crawling and burrowing
• Independent growth of organs from the
body wall
• Cushioning
• Skeletal function
• Circulation of nutrients and wastes
acoelomate
pseudocoelomate
(muscles, not
peritoneum)
eucoelomate
peritoneum
Eucoelomate
Body Design
compare Hickman
Fig. 9.12 and 9.13
ectoderm
mesoderm
endoderm
Coelom: fluid-filled cavity
between gut and body wall
that is lined with mesodermal
cells (peritoneum).
Most animals have a body cavity
• Solid, no body cavity
except for gastro vascular
cavity flatworms, cnidaria
• Pseudocoelomate- internal
space in contact with
digestive tract,
roundworms
• True coelom - internal
space lined by tissue - all
other animals
Metamerism/Segmentation
Hickman Fig 9.14
Metamerism/Segmentation
• Serial repetition of similar
body segments
• Each segment is called a
metamere or somite
• True metamerism is found in
Annelida, Arthropoda,
Chordata
Metameres in Polychaeta
metamere = segment, or repeating body unit
Arthropod Tagmata
tagmata = metameres fused into functional
units; singular is “tagma”
3 basic tagmata in all arthropods:
• head, thorax, abdomen
– head + thorax = cephalothorax
– thorax + abdomen = trunk
Segmentation and
Anatomy
Metameres of an insect
9 - 12
3
6
Summary
Pop quiz
• What are the 3 types of body cavity
organization mentioned in chapter 9?
• List the 4 basic animal tissue types.