Transcript Animal Body Systems

Animal Body
Systems
Objectives…(At the end of this lecture you should be able to):
Summarize the functions of the digestive, respiratory,
circulatory, nervous, skeletal and excretory systems.
Compare a gastro vascular cavity with a one-way digestive
system.
Differentiate open from closed circulatory systems.
Distinguish asexual from sexual reproduction.
Body Systems are specialized
to carry out different tasks
 Simple animals like
sponges carry out the
many tasks of living with
little specialization in the
cells of their body.
 More complex animals
have evolved tissues
and organs that are
specialized to perform
specific functions.
Body Systems are specialized
to carry out different tasks
 Seven important functions of these
tissues and organs are :







Digestion
Respiration
Circulation
Conduction of nerve impulses
Support
Excretion
Reproduction
Digestion
 Purpose: Obtain energy &
nutrients
 Sponges digest their food with
their body cells
 Simple animals, such as
flatworms, have a gastro
vascular cavity: a digestive
cavity with only one opening.
 More complex animals, like us,
have a digestive tract with two
openings: mouth and anus.
Respiration
 Purpose: Exchange oxygen and
carbon dioxide gases
 Can only take place across a
moist surface.
 In simple animals like jellyfish
gasses are exchanged directly
with their environment through
diffusion.
 More complex animals have
specialized respiratory
structures like gills or lungs.
Circulation
 Purpose: Transport oxygen and
nutrients to the other parts of the
body
 There are 2 types of circulatory
systems:
 Open: heart pumps fluid containing
oxygen through a series of vessels &
is dumped into the body cavity.
 Closed: heart pumps blood through a
system of blood vessels. The blood
stays in the vessels the whole time.
OPEN:
CLOSED:
Conduction of
nerve impulses
 Purpose: Coordinate the
activities in an animal’s body
and allow animal to sense
and respond to environment.
 Simple animals, like hydra,
have little coordination
among their nerve cells.
 Complex animals, like
grasshoppers, have nerve
cords/ganglia & a brain.
Support: Skeletal
 Purpose: Provide a framework
that supports the body.
 Many soft-bodied invertebrates
have a hydrostatic skeleton
made of water like a filled water
balloon.
 Other invertebrates, such as
insects & crabs, have an
exoskeleton: a rigid external
skeleton.
 Complex animals, like dogs,
have an endoskeleton: hard
material such as bone
embedded within the animal.
Excretion
 Purpose: Removal of
wastes from cellular
metabolism (CO2, ammonia,
etc.)
 Simple aquatic invertebrates
& some fishes pass it
through their skin/gills by
diffusion.
 More complex animals have
specialized excretory
structures like kidneys.
Reproduction
 Purpose: produce offspring to
ensure that the species
survives
 Two types of reproduction:
 Asexual: does not involve fusion
of two gametes.
 EX: A sponge can reproduce by
fragmenting its body. Sea
anemones pull apart into 2
individuals
 Sexual: a new individual is
formed by the union of a male
and female gamete.
 EX: egg + sperm = fertilization =
blastula
Is this sexual or asexual
reproduction?
Fun & Funky Fact:
Sea “horse” reproduction
 Pregnant sea horse
fathers give birth.
 A female sea horse
inserts her eggs into
a pouch on the male’s
abdomen, where they
are fertilized. The
male incubates the
eggs until they are
fully developed and
then gives birth to tiny
sea horses.
Fertilization
 There are two types of
fertilization:
 External: occurs outside the body
 EX: Most aquatic animals simply
release the male and female gametes
near one another in the water, where
fertilization occurs…..think opening
scene of Finding Nemo….they were
outside the mom.
 Internal: occurs inside the females
body
 EX: Animals that live on land don’t
have water so the gametes would dry
out. Internal fertilization allows it to
take place in a moist environment.
Objectives…
(At the end of this lecture you should be able to):
•Summarize the functions of the digestive,
respiratory, circulatory, nervous, skeletal and
excretory systems.
•Compare a gastro vascular cavity with a oneway digestive system.
•Differentiate open from closed circulatory
systems.
•Distinguish asexual from sexual reproduction.
Quick Test

Which two body systems in most
animals are involved in taking up
oxygen from the environment and
transporting oxygen to body cells?
a)
b)
c)
d)
Digestive & Respiratory
Respiratory & Circulatory
Circulatory & Nervous
Nervous & Excretory
The correct answer is: