Rat Dissection

•      We will break up this dissection into 6 parts; External Features, Respiratory system, Digestive System, Circulatory System, Excretory System, and Reproductive system.

•      You are responsible to know the functions and location of the organs and features gone over in this lab.

•      This lab will be split up into 5 days

–    Day 1, External features and Respiratory system

–    Day 2, Digestive System

–    Day 3, Circulatory System

–    Day 4, Excretory and Reproductive System

–    Day 5, Reproductive System and make up

•      You will have a particle exam on the Monday after the dissection


•      Use your razor blade to cut along dotted line, CAREFULL!

•      Don’t cut to deep but deep enough to get through muscles

•      You are going to have to break the ribs to get into the upper Thoracic cavity

•      Good Luck



External Features/ Respiratory

•      Ear

•      Whisker

•      Nostril

•      Mouth

•      Anus

•      tail

•      claws

•      Eyes


•      Mouth

•      Larynx

•      Trachea

•      Bronchus

•      Lung

•      Diaphragm


Functions of external an respiratory systems

•       External Features:

–    Diaphragm- This is a muscular sheet that separates cavities and its action is to draws air into the lungs.

–    Ear, Whisker, Nostril, Eyes – Sensory organs

–    Tail – Balance

–    Claws – defense, eating, grasping, climbing

•       Respiratory System:

–    Mouth and Nostril – Intake for air

–    Larynx – produce sound for communication

–    Trachea – Tube to bring air into lungs

–    Bronchus – Branches into lungs

–    Lung – Exchange oxygen form air into blood an expel carbon dioxide waste

–    Diaphragm  - Muscle that helps fill lung with air








Digestive System

•      Mouth

•      Epiglottis

•      Esophagus

•      Gall Bladder (rat doesn’t have one)

•      Pancreas

•      Stomach

•      Small intestine

•      Mesentery

•      Large intestine

•      Caecum

•      Rectum

•      Spleen



Functions of Digestive system

•       Mouth – Break down food both mechanically and physically

•       Epiglottis –Barrier to prevent food from entering the lungs

•       Esophagus- Muscular tube to carry food to stomach

•       Pancreas- This organ gives digestive enzymes to the small intestine.

•       Stomach- This is a curved, bag-like structure under the left side of the liver. Helps break down food both chemically and physically

•       Small Intestine- This is a long, coiled tube that leaves the stomach. Absorption and digestion of food takes place here.

•       Mesenteries- These are translucent membranes attached to and holding the internal organs in place. Blood vessels travel along them and fat bodies are often present.

•       Large intestine – Long tube that collects waste

•       Rectum – Last stop, This is the muscular organ, which removes water from waste and helps expel the waste from the body.

•       Cecum -  contains bacteria that help the rat to break down cellulose

•       Spleen- This organ stores red blood cells and manufactures white blood cells.










Circulatory System

•      Heart

•      Pericardium

•      Vena Cava

•      Aorta

•      Left and Right Atrium

•      Left and Right Ventricle

•      Vein

•      Artery

Functions of Circulatory System

•      Heart – pump that supplies the body with blood

•      Pericardium- protects the heart

•      Vena Cava- supplies used blood to Right atrium

•      Aorta – Main artery out of left ventricle

•      Left Atrium and Ventricle – chambers that pump blood to body

•      Right Atrium and Ventricle – chambers that pump blood to the lungs

•      Vein – (back to heart), pathway for used blood

•      Artery – (away from heart), pathway for oxygen rich blood(except pulmonary arteries)




Excretory System

•      Kidneys

•      Liver

•      Ureter

•      Urethra

•      Urinary Bladder



Functions of Excretory System


•      Liver- This is a large, brown organ takes up most of the anterior of the cavity. It consists of four lobes, and is used for removing toxins from the blood.

•      Kidney- This organ filters wastes from the blood.

•      Ureter- This is a tube that carries the wastes away from the kidney.

•      Urinary Bladder- This organ is a sack which temporarily stores urine.

•      Urethra- This organ is the tube that passes out of the bladder to the outside of the body.




Female Reproductive System

•      Uterus

•      Ovary

•      Vagina


•      Ovary- An egg producing gonad of the female.

•      Uterine horn (uterus)- female reproductive structure where eggs are stored or fertilixed or where development of the youn occurs.

•      Vagina- muscle tube for receiving sperm.



Female repro



Male Reproductive System

•      Testes

•      Scrotum

•      Vas Deferens

•      Penis

Functions of Male Reproductive System

•      Testes – gamete producing organ

•      Scrotum – Contain Testes

•      Vas Deferense – tube that carries sperm

•      Penis – organ that deposits sperm in the female reproductive system



Male repro



•      http://www.utm.edu/~rirwin/RatAnat.htm

•      Rat Quiz

•      http://www.utm.edu/~rirwin/RatAnat.htm

•      Test Questions

•      http://faculty.fmcc.suny.edu/mcdarby/Pages/Lab%20Exercises/Rat.htm