Dissection of the Rat
An Exploration of the Various Organs
Systems
Day 1: Guiding Questions #1
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6.
7.
Make a list of instruments you’ll be using and the number of
each.
After reading the objectives of the lab, how many organs for
each system are you required to know and identify.
Name the two major regions of the integumentary system.
Name three functions of this system.
Name the four key parts to the skeletal system. What does
Hemopoiesis mean?
What is the only function of the muscular system? Name the
three parts of the body mentioned that the muscular system
plays a role.
Name the three parts of the nervous system. Which parts
make up the central nervous system?
Name two functions of the endocrine system. What chemical
is produced by the glands that make up this system? How is
this system different from the nervous system? Name the eight
types of organs that make up this system.
Guiding Questions #2
1. What purpose does the circulatory system serve?
What is it primarily composed of?
2. Name the six key structures that make up the
respiratory system. What purpose does this system
serve? Name the minute little sacs in the lungs that
help with gas exchange.
3. Name the six parts of the digestive system. Where
does digestion begin? Which part of the system is
used to remove water from the food?
4. What roles do the pancreas and liver play in the
digestive process?
5. Name one of the key waste products excreted by the
Urinary system. Name the four main organs of this
system.
6. Name the key structures of the male and female.
Initial Procedures to Begin the
Dissection
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Dissection Guide: turned to the appropriate pg.
Instruments: see list
Paper towels
Water cup (half-filled) & dropper
Lab coat (optional)
String tied to each limb to immobilize the rat.
Freezer Bag: Names of lab partners (2-3)
-Preliminary (male & female) names for your rat
Guiding Questions #3
1. From your dissection guide which chapter discusses the
muscular system?
2. Before identifying the muscles the rat must be skinned.
The first incision to be made begins on the
surface of the _____ and continues down to the point
just anterior to the ______.
3. Circumvent cuts are made to the (right,left) by the
genetials and mouth. How does the guide suggest that
you separate the skin from the body?
4. Before separating the muscles and identifying them you
first need to remove the tough white connective tissue
that surrounds the muscles. Name this tissue.
5. Using Figure 14 (lateral view) list all of the muscles
labeled in the diagram. You will ID these in your rat
first.
General Rules
• No Food or Drink at your Station at all times
• Remain at your station at all times unless
instructed
• Keep track of all instruments (do a count everyday)
• No open toed shoes
• Do not cut anything unless instructed
• Always follow your Dissection guide
Instruments
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1 dissecting pan
1 Lg. Freezer Bag
4 pieces of string (25 in each)
2 forceps (fine & blunt)
1 scapel
2 blunt probes
4 sharp probes
12 pins
2 scissors (tissue & paper)
Water dropper & cup
Ruler
Index card (labels)
Basic Procedure
1.
2.
3.
4.
Ventral Incision & Extension to the limbs
Separating skin from the underlying muscles
Separate the fascia off the muscle
Identify the indicated muscles
-Make labels for structures listed on overhead
Separate & ID these Muscles (10 muscles)
-Masseter
-Sternomastoideus
-Spinodeltoideus
-Latissimus dorsi
-Triceps
-Brachialis
-Biceps femoris
-Gluteus Maximus
-Tensor fascia Latae -Semitendinosus
Please use the following in your guide:
Lateral View (Pg. 16, Fig 14)
Lateral View of the Muscles
Muscles to locate & ID from
Ventral view (14 muscles)
-Pectoralis major
-Pronator teres
-Palmaris longus
-Pectoralis minor
-External oblique
-Gracilis
-Vastus medialis
-Biceps brachii
-Flexor carpi radialis
-Triceps
-Rectus abdominus
-Sartorius
-Gastrocnemius
-Semimembranosus
Ventral View of the Muscles
Guiding Questions #4
(Ch. 4 Digestive system)
1.
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4.
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6.
7.
8.
Name the three pairs of salivary glands commonly found in the
rat.
Within the mouth cavity if you were to look inside you would
observe a hard and soft palate. Where are they specifically
located?
After opening the abdominal cavity you should be able to
locate the esophagus and follow it to the stomach. Name two
structures that would be located next to the stomach.
On page 28 of your guide sheet the diaphragm separates two
cavities. Name them.
How many lobes is the liver is divided into? Name them.
Name the three regions of the stomach. How is the great
omentum different from the lesser omentum?
Where is the spleen located with reference to the stomach?
Name all of the structures discussed from #11 to #19.
Guiding Questions #4
(Ch. 4 Digestive system cont’d)
Tasks to still complete:
Finish separating the intestinal tract from the mesentery
Transect the intestine from STOMACH end off the
esophagus
-Measure the length of the intestines (____ cm.)
-Make a cross section of the stomach and make
observations
-Label all key structures
Be sure you have the following labels
and pin these on your rat
Set #1
-Liver (left lateral lobe)
-Heart (atrium & ventricle)
-Small intestine
-Spleen
-Kidney (right)
-Lung
-Diaphragm
-Thymus gland
-Mesentery
-Large intestine (caecum)
Set #2
-Ureter
-Jugular (left)
-Trachea
-Vena Cava
-Aorta (abdominal)
-Iliac artery
-Renal artery & vein
-Carotid (right)
*(2) male or two female struct.
Contents of the Abdominal & Thoracic Cavities
Digestive System
Guiding Questions #5
(Ch. 5 Circulatory system-Pgs 31-36)
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6.
What was injected into the veins and arteries of your rat? Why
was this done?
The pericardial membranes surround the
. Name the two
types of membranes present. How are these two membranes
different from each other?
Which area (chamber) does blood enter the heart? Name the
vein that drains blood from the lungs to the left atrium.
Name the structure that divides the two ventricles of the heart.
How many branches come off the aortic arch? Name them.
Where are the following arteries found?
-coronary, carotid, subclavian, hepatic, gastric, femoral, caudal and intercostal?
7.
8.
Is the jugular a vein or artery?
What is the difference between an artery and a vein? Which one
moves blood away from the heart?
Tasks to complete for the Circ.
System
• Find the FIVE major vessels off the aorta
• Cross section of the heart
• Trace major blood vessels in the arms and
legs
Internal Chambers of the Heart
Thoracic Cavity
Arterial System
Guiding Questions #6
1. Name the five branches that come off the aortic arch.
2. How many chambers does the heart have? (After
splitting the heart in two).
3. Find the following blood vessels in your rat and label
them: Carotid artery, Pulmonary artery, Vena Cava,
Aorta, Renal, and iliac arteries (left & right).
5. Name the gland that sits on top of the kidney. (see
Chapter IV.
6. The kidney are said to be “retroperitoneal” what does
this mean?
7. Name the small tubular structure that comes out of the
kidney and into the urinary bladder
Tasks to Complete for Urinary
System
• Trace the three main structures that come to
and from the kidney
• Trace the ureters from the kidney to the
bladder
• Locate adrenal glands
• Cross section of the kidney
Male Reproductive System
Female Reproductive System
Tasks to Complete for Reproductive
System
• Determine sex
• Find major structures to verify the sex