Worm Dissection2014

WARNING: STAY FOCUSED IN THIS LAB

NO MESSING AROUND OR YOU WILL RECEIVE A 0!!

Identification of External Anatomy

Mouth

Clitellum

Setae

Metameres

Dorsal SideVentral Side

Caudal

External Anatomy

Metamere or segment

External Anatomy

• Dorsal – It is darker and smooth.

• Ventral – Lighter and a rough feel.

• Setae – Bristles that aids in locomotion .

• Metamere – Body segments

• Clitellum – Light colored section that secretes muscus for copulation and movement.

• Caudal – Opposite end from the mouth.

Internal Anatomy

Cerebral ganglion

Pharynx

Septa

Aortic Arches

Crop

Gizzard

Dorsal blood vessel

Intestine

Stomach

Seminal vesicles

Protonephridia

Esophagus

Reproductive System

Digestive System

Internal Anatomy

Excretory System

Internal Anatomy

• Aortic Arches – 5 that pump blood through the worm.

• Seminal Vesicles – Large, light colored organs that contain the sex organs.

• Crop – Food stored before entering the gizzard.

• Gizzard Contains soil to help grind for digestion.

• Intestine – Food is digested and nutrients are absorbed.

• Dorsal Blood Vessel – A large blood vessel at the top of the digestive track.

• Cerebral Ganglion – This is the brain.

• Protonephridia – Filter out nitrogenous wastes.

Cross section of Earthworm

More Internal Anatomy

• Coelom – This is the body cavity filled with fluid that acts as a skeleton.

• Typhlosole – This is a ridge inside the intestine from the dorsal side. It enlarges the surface area of the intestine, which increases the efficiency in absorbing food.

FORMAL LAB WRITEUP

Title, Labeling

• You will have your name and period in the upper left hand corner.

• The title of your lab will be in the center of your sheet and it will be underlined.

Objective: (10 points)

• Objective: Learn the anatomy of the Earthworm through dissection.

• Materials: (5 points)

Scalpel T Pins

etc…

Procedures

• 1) I Gathered materials and read instructions.

• 2)…..

• FOR THIS LAB YOU NEED 15 to 20 PROCEDURES!!!!

• These need to be written in COMPLETE SENTENCES!

Observations – 40 points

• Respiratory/Circulatory drawing – Only include the organs used in these systems. Sections need to be defined and labeled. Drawings should be neat and labeled.

• Digestive system - Only include the organs used in this system. Sections need to be defined and labeled. Drawing should be neat and labeled.

Observation continued..

• Cross section of metamere. Label and define all terms on the section.

• Nervous system – Draw only the nervous system. Do not include organs used in other processes. Define all the terms.

Uncertainties (10 points)

• This is what could have gone wrong with your experiment and how it would affect your end results.

Conclusion: (10 points)

• Explain the circulatory, respiratory, excretory and nervous system of the worm.

• Neatness and format count.• You need to use correct punctuation and

grammar at all times! YOU WILL LOSE POINTS IF YOU don’t do this.