1. Arthropoda

2. Phylum Arthropoda

3. What is an arthropod? Have segmented body Tough exoskeleton
Jointed appendages
# of segments vary between groups

4. exoskeleton Like a suit of armor Protects and supports the animal
Made of protein and chitin
Vary in shape,size and toughness
Some have waxy covering (esp. land dwellers) to help keep water in no desiccation

5. Appendages structures that extends from the body wall
Include antennae,claws, legs
Arthro=jointed
Pod= foot

6. Evolution 600 mya first arthropod in sea
Since then moved to all parts of seas and land and air.
Evolved to have fewer segments, highly specialized appendages for feeding, movement, other functions

7. First arthropod
Many identical segments, each with a pair of appendages
Resemble trilobite
Overtime, segments lost or fused together
Spiders, insects 2-3segments
Appendages evolved
to claws and other functional parts
For Great variety today

8. Form and function of organ systems
Feeding-
Include herbivores, carnivores, omnivores
Bloodsuckers, filter feeders, detritivores, parasites
Mouth range from pinchers or fangs, to sickle-shaped jaws

9. respiration
Terrestrial-most used series of tracheal tubes that extend through out body. Air enters and leaves through spiracles
Other terrestrial use book lungs, organs of respitory tissue stacked on top of each other.looks like pages of a book
Aquatic-gills mostly
Horseshoe crab-book gills

12. circulation Open circulatory system
Heart pumps blood through arteries that branch and enter tissues.
Blood leaves the vessels and moves through body till collected in sinus near heart.
Reenters heart and is pumped again

14. excretion Malpighian tubes by land arthropods
Saclike organs that extract waste from blood
Adds it to feces or digestive wastesthat moves through gut
Aquatic athropods waste diffues out into water

16. Response Well developed nervous system
All have brain that acts as a switchboard
Ventral nerve cord coordinates movement
Most sophisticated sense organs like compound eyes with 2000 lens

17. Movement Well developed muscles
Coordinated and controlled by nervous system
Individual muscle cells that contract, pulling on exoskeleton for motion

18. reproduction Land-internal fertilization
Male has organs that place sperm in female
Some-males place a sperm packet which is picked up by female
Aquatic- internal or external
External both release gametes into water. The gametes have to find each other.

19. Growth and development
Outgrow exoskeleton-need to molt
Molting-shed entire exoskeleton and replace it with a bigger one
Controlled by endocrine system by hormones
During molting skin digest some of old exoskeleton while glands create new one. Animal pulls out of old one
Can take several hours
New exoskeleton not hard yet so vulnerable to attack