CHE106: C h e m i c a l S c i e n c e C o n c e p t s 1

AutopsyName

Partners

Date

Objectives

  • Perform a whole-body forensic dissection of a mammal
  • Identify the major anatomical features of thebody in a dissected specimen
  • Examinethe relationship between structure and function in the mammalian body

SAFETY AND HYGIENE

Do not place your hands near your mouth or eyes while handling preserved specimens.Most preservatives in use today are non-toxic to the skin butthey may cause minor skin irritations. If the preservative gets on your skin, wash with soap and water.If the preservative gets in your eyes, rinse them thoroughly with the safety eyewash.

Wear lab gloves.

Lab gloves and paper towels go in the regular trash. Skin and pieces of pig tissue and organsgo into thebiohazard bag.

After bagging your pig, rinse your tray. Wipe up your station with disinfectant. Wash your hands.

MATERIALS

Fetal pig (Sus scrofa)

Scissors

Gloves

Bone cutters

Forceps

Dissecting pans

String

Metric ruler

Triple beam balance

Weigh paper or weigh boats

Paper towels

Biohazard bag

Note: The arteries of the pig have been injected with red latex to facilitate identification of the vessels of the circulatory system.

I. External Description and Preparation for Autopsy

1. Take the body from the body bag and place it on the dissecting pan.

2. Record the following in theData Sheet: age, length, weight, sex, color, and color pattern of the skin. Record any evidence of injury.

Female: find the urogenital papilla (urinary opening) and its anatomical position with respect to the anus.

Male: find the urinary opening just below the umbilical cord and its anatomical position with respect to the anus. Find the scrotum, the sac that contains the testes.

Note: Both male and female exhibit rows of nipples.

3. Examine the anterior, posterior, dorsal, ventral, medial, and lateral external structures on the pig.

  1. The nares (nostrils) have a ______position on the pig
  2. The tail has a ______position on the pig
  3. The umbilical cord has a ______position on the pig
  4. The ears (pinna) have a ______position on the pig

4. Your instructor will demonstrate how to tie the specimen to the dissecting tray so that it is secure.

  1. Internal Examination
  1. The Thoracic (chest)Cavity

1. Obtain scissors and cut the pig as shown in the figure.

2. Use your fingers to probe the chest area. Feel the hard sternum (breast bone)and ribcage. Move your fingers down until you feel the bottom of the rib cage. This is where the thoracic cavity ends (marked X in the figure).

3. Make an upside-down V incision starting a X (line 1). Cut from X to the umbilical cord and around the cord (line 2)

4. Follow lines 3, 4, 5, 6, and 7. The thoracic and abdominal cavities are now exposed.

.

5. Locatethe following structures:

  • The larynx is used for sound production
  • The trachea is also known as the windpipe
  • The lungs (right and left) consist of lobes and are used to bring oxygen into the body and to expel carbon dioxide)
  • The heart is muscular structure that pumps blood to and from the lungs and rest of the body
  • The muscular diaphragm is the main muscle of breathing. It separates the thoracic from the abdominal cavity.

6. Remove and weigh the heart and lungs (together) and enter the data on theData Sheet.

7. Answer the following:

  1. In pigs and humans, the heart is located on which side of the thoracic cavity (right or left)?
  1. Which of the 3 structures (organs) you examined in the thoracic cavity are part of the respiratory system?
  1. Which structure (organ) is part of the cardiovascular system?

B. The Abdominal Cavity

  1. Locate the following structures in the abdominal cavity:
  • The liver is a large brown organ located just below the ribs mainly on the right side
  • The stomach is located on the left, just below the liver
  • The spleen is a thin, brown, organ lateral to the stomach. It is part of the lymphatic system and has a role in fighting disease and breaking down old red blood cells
  • The small intestine is a large coiled tube in the bottom half of the abdominal cavity. It is held in place by connective tissue
  • The large intestine (colon)is shorter but has wider coils than the small intestine. It is visible on the back wall of the lower abdominal cavity
  • The kidneys are located in the posterior portion (back) of the abdominal cavity. They are bean shaped
  • The urinary bladder is located in between the vessels of the umbilical cord in the fetal pig
  • Gently lift the liver to see the small gallbladder in the underside
  • The ovaries and uterus (female) are small. Consult your instructor
  • If your pig is a male, check to see if thetestes are in the abdominal cavity or if they have descended into their mature position in thescrotum
  1. Remove and weigh some of these organs (consult the data table) and enter the data in theData Table.
  • .
  1. Test your knowledge
  1. Identify 4 organs that are part of the digestive system
  1. Which organ makes urine? Which organ stores urine until it is released?
  1. One of the organs you examined makes bile, a fluid used in digestion. Another, small organ, stores bile. Identify these two organs
  1. The most important organ in the digestive system is the small intestine. This is where much of the digestive process occurs and also where nutrients are absorbed into the bloodstream. Which organ processes the solid wastes that will be eliminated from the body?
  1. Which organ in the female produces eggs?

III. OptionalExamination of the Nervous System

Make an incision as described on page 60 from ear to ear across the top of the skull. Separate the scalp from the skull. Expose the brain to observe.

V. Questions:

  1. What is an autopsy?
  1. List 4 possible causes of death
  1. List 4 possible manners of death
  1. Is an autopsy always required in homicide cases?
  1. What are the qualifications of person who performs forensic (medico-legal)?
  1. Why does the process of forensic autopsy begin at the crime scene?
  1. Describe the process of moving a body from a crime scene to the morgue


DATA SHEET

AUTOPSY REPORT

Name of Examiner ______

Date of Examination ______

I. External Description

Length (cm)
Weight (grams)
Sex
Color and pattern
Scars, tattoos, or moles
Evidence of injury (describe)

II. Internal Examination

Heart and Lungs (grams)
Stomach (grams)
Liver (grams)
Kidney (1) (grams)

III.Cause and manner of death (if human)

Instructor

Handouts: Instructions, figure of incisions, Data sheet

Introduction

The pigs are preserved in formaldehyde, wear gloves. They were taken from pregnant sows that were being processed for food. (the cause of death is suffocation, because when the placenta is removed, the fetus has no oxygen, the manner of death is slaughter, which is the term we use for killing animals. If a person, this would be homicide)

Autopsy is an examination of a body after death. The forensic autopsy attempts to determine the cause of death and the manner of death (the instrument or illness). There are 4 possible for humans – natural, accidental, suicide, homicide

The forensic autopsy is conducted by a pathologist, coroner, or chief medical examiner. You need an MD and certification in pathology. Hospital autopsies are different (natural cause is assumed). There is a very specific procedure used which you will read about later.

An autopsy report is always included and you have a data sheet that will form the report

You first begin with an external description of the body. record the clothing, age, sex, race, height, weight, scars, tattoos, moles, anything and everything. Also injuries or wounds and evidence of past injury.

Also include degree of rigor mortis or putrefaction

The body is moved carefully from the crime scene to the morgue where it is washed for better viewing and then the autopsy performed.

Then, incisions are made and the internal structures examined. We will look at organs in the thoracic cavity (chest) and abdominal cavity. The structures are from the respiratory, cardiovascular, digestive, urinary, reproductive, lymphatic systems

A forensic pathologist might also make some microscopic slides and send tissue for toxicology and take samples of blood and urine for drug or poison analysis.

The ME presentsthe findings in a data sheet and includes an opinion on the cause and manner of death. It is a factual report and includes only evidence that can be substantiated

There are some terms to know before beginning the autopsy.

Anterior = towards the front

Ventral = belly side

Dorsal = back side

Posterior = towards the back

Medial = towards the midline

Lateral = towards the sides

Superficial = towards the surface

Deep = away from the surface

External = outer

Internal = inner