worm dissection

front or head of worm

anterior

first section of the anterior contains ______

the mouth and prostomium

prostomium

the first segment of the worm. upper lip

earthworms lose moisture and breathe via

their skin

they have light sensitive cells across their external structure, which are scattered around the skin. these give earthworms the ability to ____

detect changes in lighting, and these cells are also sensitive to chemicals and touch

the body is separated in segments which resemble rings. each segment has a number of bristly hairs attached to it, which helps the earthworm to move around.

on mature earthworms you will find a saddle or glandular ring called a ____

clitellum

when an earthworm has mated, the clitellum will _____

secrete a sack of eggs

the final segment of an earthworm contains the ___ which is where waste is secreted

anus

earthworms are ____

annelids

annelids

segmented worms that have bodies made up of a series or ring like segments

each segment contains a pair of small excretory pores called _____

nephridiopores

earthworms are ______ so both sex organs are present

hermaphroditic

opening to oviducts

segment 14

opening to sperm ducts

segment 15

the clitellum is the enlarged structure that begins at ______. it secretes mucus that holds 2 earthworms together during mating and produces a cocoon in which eggs and sperm are deposited for external fertilization

segment 31

Pharynx

at front of earthworm

-earthworms push the pharynx from inside their mouths to grab hold of things. they pull food into their mouths and then soak it in saliva.

earthworms dont have teeth. they use strong muscles called a _____ ,along with sand and soil, to grind up the food they are eating. then travels to intestines where further broken down so it can be absorbed

gizzard

majority of earthworms have _______which are like hearts and these move around their bodies

5 aortic arches

a large blood vessel runs across the top of the earthworm and this is called the _____. this vessel contracts and pumps blood around to the aortic arches.

dorsal blood vessel

there is a further blood vessel on the lower side of the earthworm which is called the ____.

ventral blood vessel

a ventral nerve which chord runs the entire length of its body connects to the ______, which is an earthworms brain. Each segment is connected to the cord so that they can sense light and touch, and can move. Each segment is also wrapped in circular muscles, which contract to help the earthworm move.

cerebral ganglion

help the worm move through soil

setae

earthworm has no head and no appendages, but it does possess external characteristics to study.

true

crop

stores food

gizzard

grinds the food before passing it to the intestine

removes nitrogenous waste

nephridia

thin walls between each segment

septa