Biology A
Arlington High School
Name:
Class Period:
Rat Dissection Lab
Background
Dissection of any organism or organ allows a 3-dimensional look at structural connections within the
body. It is a valuable tool in learning and understanding these relationships. While texts can provide amazing
and colorful pictures it does not replace the experience of seeing and manipulating the real thing. Imagine if you
tried to learn about the structure of a car engine from only pictures but never had a look under the hood!
Why dissect a rat? The Norway rat has been a valuable tool in medical research and is commonly used in
studies of comparative anatomy. In other words, what you learn by dissection of the rat is broadly applicable to
most other mammals. Even if your primary interest is human anatomy, the rat is very similar in construction,
and most of the names that you will learn apply to human structures as well.
Please note that one very important requirement for this lab is respectful treatment of your lab specimen.
Your rat has been a living creature and that should be recognized through your treatment of the specimen
throughout the duration of the lab. Any inappropriate behavior will result in your removal from the lab for the
day.
General Lab Instructions
Laboratory Procedures
Materials: You will need to collect the following at the start of each class.
 Dissecting tray
 Preserved rat
 Dissecting tools
 Goggles for each person
- Scalpel
 Gloves for each person
- Scissors
- 2 Wooden needles
- Forceps
- Metal Probe

Lab Notes
During each dissection:
 Follow specific instructions for each dissection section
 Read all directions before beginning
 Cut as little as possible!! Keep in mind that you are dissecting not butchering. Any cuts will alter the original
structural relationships.
 There will be a daily work grade, straying from your task will result in your losing points on your rat lab.
Safety
 Goggles must be worn at all times
 Caution: preserving fluid may squirt out when the first incision is made.
 Dissection tools are extremely sharp! Handle with care. The scalpel should never leave the table.
 Any cuts must be washed and sterilized promptly and reported to Ms. Gunther.
 If preserving fluid should get in the eye(s) they must be washed with the eyewash.
 Do not put any dissecting tools in your mouth EVER!
 Any accident must be reported to Ms. Gunther IMMEDIATELY!
Grading
 Your group will study the body systems of the rat one at a time. For each system:
 Carefully read and follow dissection instructions.
 Identify every structure listed in your dissection lab packet.
 Learn functions for each structure
 Be able to answer all questions in your dissection lab packet
 Ms. Gunther will administer a quiz for each body system when your group feels it is ready. Quizzes will be oral,
group quizzes. Group members will be asked questions individually and will not be able to help one another. This
means you must make sure that you and every member of your group are prepared.
 Retakes of quizzes can be taken once per body system, for a maximum score of 100%.
 Your final grade for this project will be a sum of all daily work grades and quiz grades for body systems.
Terms and Questions for Individual Sections
External Anatomy (section1)-Meet your rat
Assigned terms
 Anterior
 Posterior
 Dorsal
 Ventral
 Lateral
Questions:
1.





Medial
Proximal
Distal
Transverse
Sagittal




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Pinna
Vibrissae
External nares (nostrils)
Hind and fore limbs
External genitalia
Is your rat is male or female? Be sure to also look at a rat of the opposite gender.
Skeletal and Muscular Systems (section 2)
Assigned terms
Skeletal Structures:
 Axial skeleton
 Appendicular skeleton
 Skull
 Mandible




Muscular Structures:

Pectoralis Major

Triceps Brachii

Biceps Brachii

External Oblique




Humerus
Sternum
Phalanges
Metacarpals
Rectus Abdominus
Quadriceps Femoris
Deltoid
Trapezius




Femur
Metatarsals
Latissimus Dorsi
Biceps Femoris
Questions
1.
2.
3.
Differentiate between the axial and appendcular skeletons
Explain the functions of the following: Pectoralis, Triceps, Biceps, Quadriceps, Deltoid.
Explain how the skeletal system and the muscular system are connected to each other in both structure and
function.
4. Compare and contrast rat and human skeletal structures. How are they skeletons specially adapted to the needs
of the particular animal?
Digestive System (section 3)
Assigned terms





Canines, incisors, molars
Hard palate
Soft palate
Tongue
Trachea
Questions
1.
2.
3.
4.





Esophagus
Diaphragm
Liver
Stomach
Small intestine



Large Intestine
Pancreas
Spleen
Identify the function of the digestive system.
Describe the function of the following: incisors, trachea, esophagus, diaphragm, liver, stomach, small intestine,
large intestine, pancreas.
Choose two organs from the abdominal cavity and explain how the structure of each organ complements its
function.
The spleen is not a part of the digestive system. To what system does it belong and what is its function?
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Respiratory and Circulatory Systems (section 4)
Assigned Terms
 Diaphragm
 Trachea
 Larynx
 Lungs
 Heart




Esophagus
Right and left atrium
Right and left ventricle
Vena Cava, anterior and
posterior



Pulmonary artery
Aorta
Carotid artery, external
and internal
Questions
1. Explain the relationship between the respiratory and circulatory systems.
2. Trace the path of oxygenated blood from the lungs throughout the heart and body.
3. What is the major difference between veins and arteries?
4. Describe the function of the following: Trachea, larynx, epiglottis, heart, lungs, aorta, anterior and posterior vena
cava, carotid artery, pulmonary vein and artery.
Urogenital System (section 5)
Assigned Terms
 Kidneys
 Ureters
Female rats
 Ovaries
Male rats
 Testes
 Epididymis

Urethra

Urinary
Bladder

Renal veins
and arteries

Oviducts

Uterine Horn

Vagina

Seminal
vesicles

Penis
**Note: You are responsible for being able to identify both male and female, so switch rats with another group to view the
opposite gender. You also need to have both male and female diagrams and terms chart.
Questions
1.
2.
3.
4.
5.
6.
Describe the functions of the urinary system.
The renal arteries and veins are not part of the urinary system. What system are they part of? What is the
function of each? How do they relate to the kidneys?
Trace the life of a sperm from initial development until it leaves the male body. State the locations of each
stage and the functions of the different organs that it passes.
Where is the egg in a female developed, fertilized, and where does the fertilized egg develop (fetal
development)?
Explain why there is such a structural difference between the human uterus and the rat uterine horn. Include the
structure and function relationship in your explanation.
Describe the function of the following: kidney, ureter, uninary bladder, urethra, ovary, uterine horn, testes,
seminal vesicles
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Nervous System (section 6)
Assigned Terms




Neuron
Olfactory bulbs
Cerebrum
Corpus callosum




Thalamus
Hypothalamus
Cerebellum
Medulla

Spinal cord and spinal
nerves
Questions:
1. What is the function of the nervous system?
2. What are the three major divisions of the brain?
3. Describe the function of the following: neuron, olfactory bulb, cerebrum, corpus callosum, hypothalamus,
cerebellum, medulla, cranial nerves, spinal cord, spinal nerves.
My Grade
Record quiz scores below to help you track your grade for the dissection. You may retake quizzes to improve your grade.
Quiz 1 External Structures:
____________/18 points
Quiz 2 Muscular/Skeletal:
____________/18 points
Quiz 3 Digestive:
____________/18 points
Quiz 4: Circulatory/Respiratory
____________/20 points
Quiz 5: Urogenital
____________/18 points
Quiz 6: Nervous
____________/18 points
Total
____________/110 points
Remember, an additional 40 points will come from class participation, time on task and appropriate lab behavior. This project
grade will be out of a possible 150 points.
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