Dissection of the Rat

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Dissection of the Rat

• An Exploration of the Various Organs Systems

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Day 1 Guiding Questions 1

• Make a list of instruments youll 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.

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Guiding Questions 2

• What purpose does the circulatory system serve?
  What is it primarily composed of?
• 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.
• 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?
• What roles do the pancreas and liver play in the
  digestive process?
• Name one of the key waste products excreted by
  the Urinary system. Name the four main organs of
  this system.
• Name the key structures of the male and female.

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Initial Procedures to Begin the Dissection

• 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
  

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Guiding Questions 3

• 1. From your dissection guide which chapter
  discusses the muscular system?
• 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 ______.
• 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?
• Before separating the muscles and identifying
  them you first need to remove the tough white
  connective tissue that surrounds the muscles.
  Name this tissue.
• Using Figure 14 (lateral view) list all of the
  muscles labeled in the diagram. You will ID
  these in your rat first.

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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

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Instruments

• 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)

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Basic Procedure

• 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

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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)

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Lateral View of the Muscles
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Muscles to locate ID from Ventral view (14
muscles)

• -Pectoralis major -Biceps brachii
• -Pronator teres -Flexor carpi radialis
• -Palmaris longus -Triceps
• -Pectoralis minor -Rectus abdominus
• -External oblique -Sartorius
• -Gracilis -Gastrocnemius
• -Vastus medialis -Semimembranosus

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Ventral View of the Muscles
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Guiding Questions 4(Ch. 4 Digestive system)

• 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.

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Guiding Questions 4(Ch. 4 Digestive system
contd)

• 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

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Be sure you have the following labels and pin
these on your rat

• Set 1 Set 2
• -Liver (left lateral lobe) -Ureter
• -Heart (atrium ventricle) -Jugular (left)
• -Small intestine -Trachea
• -Spleen -Vena Cava
• -Kidney (right) -Aorta (abdominal)
• -Lung -Iliac artery
• -Diaphragm -Renal artery vein
• -Thymus gland -Carotid (right)
• -Mesentery (2) male or two female
  struct.
• -Large intestine (caecum)

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Contents of the Abdominal Thoracic Cavities
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Digestive System
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Guiding Questions 5(Ch. 5 Circulatory
system-Pgs 31-36)

• 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?
• 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?
  

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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

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Internal Chambers of the Heart
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Thoracic Cavity
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Arterial System
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Guiding Questions 6

• Name the five branches that come off the aortic
  arch.
• How many chambers does the heart have? (After
  splitting the heart in two).
• Find the following blood vessels in your rat and
  label them Carotid artery, Pulmonary artery,
  Vena Cava, Aorta, Renal, and iliac arteries (left
  right).
• Name the gland that sits on top of the kidney.
  (see Chapter IV.
• The kidney are said to be retroperitoneal what
  does this mean?
• Name the small tubular structure that comes out
  of the kidney and into the urinary bladder

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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

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Male Reproductive System
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Female Reproductive System
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Tasks to Complete for Reproductive System

• Determine sex
• Find major structures to verify the sex