1. WORM DISSECTION

2. VIDEOS
Planaria regeneration
10 Facts about Earthworms
Annelid Worms

4. KIDSPIRATION by Riedell

5. NAMING Kingdom: Phylum: Class: ANIMALIA Annelida “little rings”
OLIGOCHAETA
“few bristles”

6. SETA (plural: setae) BRISTLES on VENTRAL surface

7. Segmentation Compartments allow individual parts to move independently
Damage insurance
If one section is damaged, others can still function
BIODIDAC

8. SEGMENTED WORMS Earthworms play an important role in soil fertility
“intestines of the earth”
-Aristotle
Return nutrients to soil by decomposing dead leaves and organic matter
Burrowing allows air and water to penetrate to roots
Tunnels loosen soil so roots can grow more easily

9. Terms to Know Dorsal: TOP of organism Ventral: BOTTOM of organism
Anterior: near the HEAD (front)
Posterior: near the BACKSIDE

10. WHICH END IS WHICH? CLITELLUM = ring Doesn’t go all the way around
Image by Riedell/VanderWal©2005
CLITELLUM = ring
Doesn’t go all the way around
Closest to anterior end
Makes mucous for reproduction

11. 2 opening digestive system
Image by Riedell/VanderWal©2005
Image by Riedell/VanderWal©2005
MOUTH ANUS
Prostomium covers/protects mouth opening senses light/dark, chemicals (food), vibration

13. EXTERNAL STRUCTURES
DORSAL BLOOD VESSEL
CAMOUFLAGE

14. CUTICLE (non-cellular protective layer)

15. INTERNAL STRUCTURES

16. COELOM = space around organs
Image by Riedell/Vanderwal ©2005

17. SEPTUM (pl. SEPTA) Dividing walls separate coelom into compartments
Fluid in coelom provides support = HYDROSTATIC SKELETON
(water skeleton)
Image by Riedell/Vanderwal ©2005
Image from: BIODIDAC

18. CLOSED circulatory system
DORSAL BLOOD VESSEL
VENTRAL BLOOD VESSEL

19. DORSAL BLOOD VESSEL Image by Riedell/Vanderwal ©2005
Images by Riedell/VanderWal©2005
Image by Riedell/Vanderwal ©2005

20. 5 AORTIC ARCHES act as “heart” to pump blood
Image by Riedell/Vanderwal
Image by Riedell/Vanderwal ©2005

21. Image by Riedell/Vanderwal ©2005
PHARYNX
PHARYNX

22. INTERNAL STRUCTURES CROP-stores food waiting to be digested
Image by Riedell/Vanderwal ©2005  
CROP-stores food waiting to be digested
GIZZARD- grind and mash food

23. INTESTINE- absorbs nutrients
Images by Riedell/Vanderwal ©2005
WORMS HAVE ADAPTATIONS for eating “SOIL”
1. REALLY LONG INTESTINE so food spends long time passing through
2. TYPHLOSOLE- ridge inside increases surface area for more absorption

24. EXCRETORY SYSTEM
Osmoregulation: Collect & excrete NITROGEN WASTE to maintain HOMEOSTASIS
Use the
NEPHRIDIUM
(act like a kidney)

25. SEXUAL REPRODUCTION Earthworms are hermaphrodites
HAVE BOTH MALE & FEMALE
REPRODUCTIVE ORGANS in same worm

26. EXTERNAL STRUCTURES MALE GENITAL PORE- releases sperm to give away
EXTERNAL STRUCTURES
MALE GENITAL PORE- releases sperm to give away
FEMALE GENITAL PORE- releases eggs
OPENINGS to SEMINAL RECEPTACLES- receive
sperm from other worms when trade

27. SEXUAL REPRODUCTION EXTERNAL FERTILIZATION
Produce a
COCOON
made of MUCOUS
and CHITIN
(tough carbohydrate)
Baby worms hatch
after a few weeks

28. REPRODUCTIVE SYSTEM SEMINAL RECEPTACLES
Image by Riedell/Vanderwal©2005
SEMINAL RECEPTACLES
Store sperm received from other worms

29. REPRODUCTIVE SYSTEM SEMINAL VESICLES STORE WORM’S OWN SPERM
Image by Riedell/Vanderwal©2005
STORE WORM’S OWN SPERM
TO “GIVE AWAY”

30.   UNDERNEATH DIGESTIVE SYSTEM VENTRAL NERVE CORD
Image by: Riedell/Vanderwal © 2005  
UNDERNEATH DIGESTIVE SYSTEM
VENTRAL NERVE CORD
(nerves usually white)
VENTRAL BLOOD VESSEL (usually dark)

31. BODY PLANS are also flipped!
Most INVERTEBRATES have a DORSAL HEART
and a VENTRAL NERVE CORD
ALL VERTEBRATES have a DORSAL NERVE CORD and a VENTRAL HEART.