Fetal Pig Dissection—Part I



Fetal Pig Dissection—Part I

Taxonomy

Kingdom - ____________________

Phylum - Chordata

Class - _______________________

Order - Artiodactyla

Genus - ______________________

Species - _____________________

Materials Needed

∑ Dissecting tray, dissecting instruments, gloves, 4 pins

∑ One pig per 2-3 partners

∑ Purple lab book with fetal pig on cover - Photo Manual and Dissection Guide of the Fetal Pig

∑ Two strings per lab group

Introduction:

Fetal pigs are unborn animals. They are byproducts of the pork industry. This means that when pregnant sows (mature female swine) are killed for meat, the unborn babies are either removed for biological study (specimens in biology classes), or they are discarded and ground up as fertilizer. There are as many as 7-12 young in a single litter.

Which option would you prefer?

Fetal pigs are mammals, which are backboned animals, also known as ____________________________________.

Two chief mammalian characteristics that set them apart from the other class of vertebrates are:

1. Skin covered with or

2.

Telling the Age

1. The age of the fetal pig can be estimated by measuring the body length from the tip of the snout to the attachment of the tail (not including tail). Compare this length to the data given on relative sizes of a fetal pig at different times during gestation.

|Centimeters |Millimeters |Approximate |

|(Length of |(Length of |age of |

|fetus) |fetus) |Fetus (days) |

|1.1 | |21 |

| |17 |35 |

|2.8 | |49 |

|4.0 | |56 |

| |220 |100 |

| |300 |112-115 |

| | |(full term) |

*What type of external symmetry does a fetal pig have?

*What type of internal symmetry does a fetal pig have?

∑ What is the length of your fetal pig (in centimeters)?

∑ What is the approximate age of your fetal pig?

Identify External Anatomy:

___Anterior ______Posterior _____ Dorsal Ventral

Head (cranial) region

Neck (cervical) region

Trunk region/Abdomen

___Thoracic ___Lumbar ____Sacral

___Tail (caudal) region

How to Identify Males/Females:

Males:

∑ Prominent urogenital

opening under umbilical cord

∑ Scrotal sac (swelling)

∑ May feel penis under skin between urogenital

opening and scrotal sac (penis is internal)

Females

∑ Urogenital papilla (small, fleshy cone-shaped projection)

near anus and tail

∑ LACK OF scrotal sac swellings

∑ Tail usually curly/curlier than males

Important ! ! !

If you have a female pig, examine a male pig from another group to see the differences.

If you have a male pig, examine a female pig from another group to see the differences.

*What sex is your fetal pig? _____________________

Now that you know the sex of your fetal pig, you can name her/him.

∑ Name of your fetal pig ____________________

Tying and Cutting the Fetal Pig

1. Tie the fetal pig down to dissecting tray using two strings—one string for the arms, the other string for the legs.

DO NOT TIE STRING IN KNOTS—MAKE IT ADJUSTABLE!!!

1. Make an incision at the hairy papilla/chin with your scalpel and continue to the umbilical cord. Cut around umbilical cord on both sides.

Females: Direct two cuts around umbilical cord into one line and continue cutting between legs

Males: Direct two cuts around the umbilical cord, but continue two incisions separately and keep them apart between legs

Cutting Through the Body Wall

1. Carefully make incisions deeper, but be very careful not to cut into internal organs beneath skin.

2. Cut the edges of the diaphragm (flap of tissue covering liver) from the body wall.

3. Make lateral flaps:

∑ Cut caudal to (behind/beneath) the forelimbs; cut away from center of body

∑ Cut anterior to (in front of/above) hind limbs; cut away from center of body

∑ Pin lateral flaps to dissecting tray.

4. Next, find umbilical vein (leads from umbilical cord into liver) and cut it. Pull strip of flesh back.

5. Snip the very end off of the umbilical cord and observe the two umbilical arteries (injected with red latex dye) and the umbilical vein (injected with blue latex dye) inside.

Fetal Pig Dissection - Part II

Materials Needed

∑ Dissecting tray, dissecting instruments, gloves, pins

∑ One pig per three-four partners

∑ Purple lab book with fetal pig on cover—Photo Manual and Dissection Guide of the Fetal Pig

∑ The Concise Fetal Pig picture guide

∑ Two strings per lab group (use the same strings you used for Part I)

Digestive System

1. Do fetal pigs have a gastrovascular cavity or a digestive tract?

2. Is the digestive system a one-way (food travels in and waste travels out different openings) or a two-way system (food travels in and waste travels out the same opening)?

3. What is/are the opening (s) in the fetal pig?

Identify the Parts of the Digestive Tract

___ Mouth

___ Hard Palate

___ Soft Palate

___ Tongue

___ Papillae

___ Esophagus (smooth tube that carries food from the mouth to the stomach; not ribbed)

___ Stomach

___ Pyloric Sphincter (ring of muscle that regulates the release of partially digested food into the duodenum); in between

stomach and small intestine.

___ Small Intestine (duodenum, jejunum, ileum)

___ Mesentery (holds small intestine to body wall; clear with blood vessels running through it)

___ Caecum (small sac between the part of the small intestine, called the ileum, and large intestine)

___ Large Intestine (also known as colon)

___ Rectum (thick tube that lies on the body wall; in between the large intestine and the anus)

___ Anus

______ STICKER!

___ Liver

___ Gall Bladder (sac-like structure embedded within the right lobe of the liver; must look at

underside of liver to find)

___ Cystic Duct(transports bile stored in the gall bladder)

___ Hepatic Duct( comes from the liver; transports bile made in the liver to the small intestine)

___ Common Bile Duct (this duct forms when the cystic duct and the hepatic duct combine together

into one; this duct goes into the duodenum - the first part of the small intestine)

___ Pancreas (looks spongy like cauliflower; look underneath the stomach to find)

______STICKER!

Identify the Parts of the Abdominal Cavity NOT in the Digestive Tract

___ Peritoneal cavity (abdominal cavity)

___ Diaphragm (dome-shaped muscular wall that separates the thoracic cavity from the abdominal cavity)

___ Peritoneum (thin, clear tissue that covers the organs and holds them in place)

___ Spleen (long, thin organ)

___ Greater Omentum (thin, clear tissue that holds the spleen to the bottom of the stomach)

___ Kidney

______ STICKER!

Fetal Pig Dissection - Part III

Materials Needed

∑ Dissecting tray, dissecting instruments, gloves, pins

∑ One pig per three-four partners

∑ Purple lab book with fetal pig on cover - Photo Manual and Dissection Guide of the Fetal Pig

∑ The Concise Fetal Pig picture guide

∑ Two strings per lab group (use the same strings you used for Part I & II)

∑ Straw

Procedure

1. Before identifying organs of the Thoracic Cavity that are part of the Respiratory System, watch the “Respiratory System” part of the Boreal Laboratories Fetal Pig Dissection video.

Identify the parts of the Respiratory System

___ Diaphragm

___ Glottis

___ Epiglottis

___ Larynx

___ Trachea

___ Lungs (4 lobes on right, 3 lobes on left)

______ STICKER!

***Using a straw, try to blow and inflate the lungs!

Place the straw over the glottis/epiglottis and blow. It will be difficult to do, since the fetal pig has never taken a breath of air. They are very dense, because the fetal pig has only breathed water in the womb.

Identify Glands in the Thoracic Cavity that are NOT part of the Respiratory System

___ Thyroid Gland

___ Thymus Gland

______ STICKER!

[pic]

Fetal Pig Dissection - Part IV

Materials Needed

∑ Dissecting tray, dissecting instruments, gloves, pins

∑ One pig per three-four partners

∑ Purple lab book with fetal pig on cover—Photo Manual and Dissection Guide of the Fetal Pig

∑ The Concise Fetal Pig picture guide

∑ Two strings per lab group (use the same strings you used for Part I & II)

∑ Straw

Procedure

1. Before identifying organs of the Thoracic Cavity that are part of the Respiratory System, watch the "Respiratory System" part of the Boreal Laboratories Fetal Pig Dissection video.

Identify the parts of the Circulatory System

___Heart

___ Right Atrium

___ Left Atrium

___ Right Ventricle

___ Left Ventricle

___ Coronary Vessels (include both coronary artery and coronary vein—usually can't tell the difference)

___ Apex (tip of heart; point)

___Pulmonary Artery

___Ductus Arteriosis (short duct only in fetal animals that connects the pulmonary artery to the aorta)

___ Aortic Arch (curves/arches)

___ Aorta (continues from curve/arch and runs along the back of the fetal pig)

___ Umbilical Arteries

___ Umbilical Vein

∑ Is the circulatory system of a fetal pig an open or closed circulatory system? Why?

______ STICKER!

Identify the parts of the Urinary System.

Kidneys

Peritoneum

Ureters

Urinary Bladder

____ Urethra

______ STICKER!

ANTERIOR ARTERIES

[pic]

FEMALE UROGENITAL SYSTEM

Fetal Pig Dissection - Part V

Materials Needed

∑ Dissecting tray, dissecting instruments, gloves, pins

∑ One pig per three-four partners

∑ Purple lab book with fetal pig on cover—Photo Manual and Dissection Guide of the Fetal Pig

∑ The Concise Fetal Pig picture guide

∑ Two strings per lab group (use the same strings you used for Part I, II, III, & IV)

Procedure

1. Before identifying parts of the Central Nervous System, watch the "Central Nervous System" part of the Boreal

Laboratories Fetal Pig Dissection video.

1. Directions for exposing brain and spinal cord:

a) With a scalpel, make an incision around the upper part of the cranium. Extend the incision along both sides of the spinal

cord to the tail.

b) Next, deepen that incision using scissors.

c) Peel back and remove the skin with the fingers.

d) Use scissors to cut along the exposed portion of the skull. Use forceps to lift and remove the cartilaginous part of the

skull.

e) If the meninges (membranes that cover the brain) do not peel off with the skin, remove them by cutting between the

cerebral hemispheres.

a) To see the spinal cord, you may have to cut through vertebrae covering the spinal cord. This can be difficult to do!

Identify the parts of the Central Nervous System.

Meninges

Cerebrum

Longitudinal Cerebral Fissure

Sulci

Gyri

Cerebellum

Medulla Oblongata

Spinal Cord

_____ Spinal Nerves

_________ STICKER!

Congratulations!

YOU ARE OFFICIALLY DONE DISSECTING THE FETAL PIG!!!!!!!

-----------------------

cervical

___Snout

___External nares (nostrils)

___Umbilical cord

___Pinnae (external ears)

___Eyes

___Nictitating membrane (cover eyes) ___Mouth

___Tongue

___Umbilical cord

___Mammary papillae (teats/nipples)

___Anus

Forelimb/Forearm

___4 digits

___Wrist

___Elbow

___Shoulder

Hindlimb

___4 digits

___Ankle

___Knee

___Hip/Thigh

_____ STICKER!

Neck

Head region region Trunk region Tail region

Tongue

Knee

Appendages

Foot

Digit Toes

Hind limb

Ankle

Tail

Thigh

Hip

Umbilical cord

Umbilical

arteries

Umbilical vein

Elbow

Shoulder

Forearm

Upper arm

Wrist

Forelimb

Eye

External Nares

Eyelids

Sacral

Lumbar

Thorax

Ear (Pinnae)

Abdomen

Teats (nipples)

Umbilical cord

Urogential opening

Genital papilla

Scrotal sac

______Sticker!

Look at the picture!!

EPIGLOTTIS

OPENING TO GLOTTIS

SOFT PALATE

HARD PALATE

CANINE

INCISOR

FIGURE 4.2 Palate, tongue, and oropharynx of the fetal pig.

PAPILLAE

TONGUE

PAPILLAE

Cystic duct + Hepatic duct = common bile duct

THE ABDOMINAL CAVITY (CLOSE-UP)

Lobes of

VISCERAL ORGANS (CLOSE-UP)

THE THORACIC CAVITY

Left Carotid Artery

Right Jugular Vein

Subscapular Vein

Axillary Vein

Long Thoracic Artery

Cranial Vena Cava

Pulmonary Arch/artery

Right Atrium

Right Ventricle

Coronary Artery (Red)

Coronary Vein (Blue)

Left Ventricle

Left Atrium

Ductus Arteriosus

Systemic Aorta

Brachiocephalic Artery

Subclavian Artery

Axillary Artery

Internal Thoracic Artery

Thyrocervical

Urogenital Papilla

Tail

Right

Sulci

(grooves)

Gyri

(folds of tissue)

Longitudinal

Cerebral Fissure

Cerebellum

Medulla Oblongata

BRAIN (Dorsal View)

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download