Bio200

Front 1

classification scheme of Annelida

Back 1

phylum annelida
class polychaeta (clamworms)
class oligochaeta (earthworms)
class hirudeinea (lichens)

Front 2

metamerism

Back 2

the body of annelids is divided into a series of segments or metameres. Externally this is exhibited by grooves which encircle the body, internally by septa or membranes which act as partitions

Front 3

hydrostatic skeleton of coelomic fluid

Back 3

coelomic fluid in annelids functions as a hydrostatic skeleton against which the muscles act to change body shape

Front 4

cuticle

Back 4

on the surface of an annelid there is a tough skin or cuticle with hard bristles

Front 5

straight digestive tract

Back 5

annelids posses a more or less straight digestive tract running from the mouth to the anus

Front 6

closed cirrculatory system

Back 6

annelids posses a well developed circulatory system in which the blood is confined to vessels

Front 7

segmented nervous system

Back 7

the annelid nervous system consists of the brain and two verntral nerve cords with a pair of ganglia in wach segment

Front 8

prostomium

Back 8

the first fleshy lobe of the head lying in front of the mouth it has numeroud sensory organs including the eyes and tentacles or antennae

Front 9

eyes

Back 9

light sensitive sensory organs on the prostomium

Front 10

antennae (tentacles)

Back 10

sense organs for touch and taste found on the prostomium

Front 11

mouth

Back 11

opening at the begininng of the digestive tract under the prostomium

Front 12

parapodia

Back 12

fleshy lobes for gas exchange extend from body segments

Front 13

chaetae (setae)

Back 13

bristles on the parapodia these are used for locomotion

Front 14

anus

Back 14

opening at the end of the digestive tract at the posterior end of the worm

Front 15

cutivle

Back 15

the skin covering the suface of the worm

Front 16

somites

Back 16

body segments plainly visible in annelids inside the body the segments are separated by membranes called septa

Front 17

cirri

Back 17

long bristles serving as organs of touch near the anus

Front 18

pharynx

Back 18

first part of the digestive tract leading from the mouth

Front 19

esophagus

Back 19

part of the digestive tract leading from the pharynx that opens into the intestines

Front 20

esophageal caecum

Back 20

secretes enzymes and increase surface area for digestion

Front 21

stomach/intestine

Back 21

structure where digestion and absorption takes place found following the esophagus

Front 22

rectum

Back 22

last part of the digestive tract which opens out of the anus

Front 23

dorsal blood vessel

Back 23

structure through which blood flows antertiorly found about the digestive tract

Front 24

ventral blood vessel

Back 24

structure through which blood flows posteriorly found beneath the digestive tract

Front 25

lateral vessels

Back 25

blood vessels which connect the dorsal and ventral vessels together, passing around the digestive tract

Front 26

what serves the function of simple gills in the clamworm?

Back 26

parapodia

Front 27

dorsal ganglion

Back 27

bilobed structure that coordinates nervous function. Found in the prostomium. "the brain"

Front 28

ventral nerve cord

Back 28

structure that carries nerve impules back and forth from the brain through the length of the worm.

Front 29

nephridia

Back 29

excretion is accomplished with these, tiny kidney units, there is a pair located in each segment of the clamworm

Front 30

gonochoristic

Back 30

there are both male and female worms, and they reprodice sexually