Pig Dissection

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Transcript Pig Dissection

Fetal Pig Dissection!

• Work in Groups of 3-4 • Get out lab books and lab packets!

Fetal Pig Dissection – Day 1

Getting Started!

Obtain the following materials: 1 fetal pig per group 1 large dissection pan 2 pieces of string - ~25-30 inches long 2 good scalpels Scissors 2

BLUNT

Probes Forceps (tweezers)

Initial Prep

• Open up the plastic bag – –

KEEP

the

outer bag

AND the

rubber band

!

– Cut open the inner bag over the sink. Empty pig and contents into sink. THROW AWAY inner bag into the

GREEN

trash • Rinse off pig well. Towel dry and place in a dissection tray

External Observations

• Look for the umbilical cord – Try to find the umbilical arteries/veins that connected its blood supply to mom via the placenta •

External nares

what those are?) (remember •

Tongue

• Boy or Girl?

– Look under the tail. • If all you see it an anus (hole) then a SMOOTH swollen sac of skin – you have found the

SCROTUM

and you have a boy!

• If you see an anus (hole) plus an obvious folded area of skin. You have found the

GENITAL PAPILLA

and you have girl!

Genital Papilla GIRL!!!

Scrotum BOY!

Anus Anus

Securing your Pig to the tray

• Use the 2 pieces of string to secure your pig to the dissecting tray

Incision Time

1. Take a scalpel cord – make a SUPERFICIAL midsaggital incision from chin to umbilical 2. Then use scissors to cut along either side of the umbilical cord to create a “flap” 3. & 4. Use scissors to make 2 lateral cuts. Avoid the staples on one side of the pig – Also be careful not to demolish the

DIAPHRAGM

at the base of the rib cage!

Incision Time

3. & 4. Use scissors to make 2 lateral cuts. Avoid the staples on one side of the pig – Also be careful not to demolish the

DIAPHRAGM

at the base of the rib cage!

Diaphragm

Separate Skin from rib cage

• Using your scapel – separate the skin of the chest area off of the rib cage.

– You will have to cut through muscle and connective tissue to do this – It’s like skinning raw chicken!

• Using scissors – cut of each half of the rib cage. You should end up with 2 large chunks of ribs in your tray

Diaphragm

• Use scissors to separate the diaphragm from the floor of the rib cage.

Diaphragm

• You should be left with one big “flap” of Diaphragm that hangs over the liver and stomach (see d

page 409 of lab book

)

Diaphragm

Exposing Larynx and Trachea – pg. 409

• Using scissors – cut off any remaining pericardial sac that might be covering the heart.

– Place any pieces in your tray for later disposal • Using a SHARP scalpel – remove all muscle and tissue overlying the larynx and trachea

Larynx Trachea

Neck Blood Vessels – pg. 418

• Using a

BLUNT PROBE

– carefully probe on either side of the trachea until you expose –

1 PINK common carotid artery

on each side –

2 BLUE jugular veins

on each side • These are the

internal and external jugular veins Common Carotid Artery Internal Jugular Vein External Jugular Vein

Heart

• Using a combination of scalpel and scissors: – Cut off the

pericardial sac

that surrounds the heart – Be careful not to cut off any important blood vessels!

Superior Vena Cava

• Also not the texture and position of the

RIGHT AND LEFT LUNGS.

Right Lung Left Lung

Cardiovascular System: Superior Vena Cava, Pulmonary Trunk & Aortic Arch

Superior Vena Cava Aortic Arch Pulmonary Trunk Right Lung Left Lung

What now? Locate all Respiratory & Digestive System organs listed on

Page 13 of your lab packet!

• Use

pg. 404 & pg. 409

in your lab books for help • Note: do NOT find the urinary organs yet – we will do this later.

• When your group thinks it has found everything – call me over so I can review it with you!

Ready to clean up?

• Cut off strings – throw away in

GREEN

trash.

• Throw any

PIG TISSUE WASTE

in the

RED

trash • Rinse pig under water and clean both external and internal areas.

• Spray pig with cavicide (in white spray bottle) inside and out!

• Put pig in your saved plastic bag and secure with rubber band. • Write the pig’s name (or group name) on the bag in permanent marker.

– Place bagged pig in the tray.

• Spray down your table with cavicide or simple green!

Respiratory System

• Make sure you can locate: – External nares – Larynx – Trachea – Diaphragm – lungs

Digestive System

• Be sure you can locate: – Tongue – Esophagus – Stomach – Liver – Gallbladder – Small intestine – Large Intestine – Pancreas – Mesentery – Rectum

Digestive System

Note: the following are not shown, but you need to know where they are:

Tongue, esophagus, stomach, pancreas Liver Gallbladder Small intestine Large intestine Mesentery Rectum

Fetal Pig Dissection – Day 2

Urinary System

• Do NOT cut out the intestines to dissect the urinary system!

• Push the intestines to one side and use a scalpel or blunt probe to remove the connective tissue around each

kidney

and

ureter

• Note the

ALLANTOIC BLADDER Right Kidney Right Ureter Rectum Left Kidney Left Ureter Allantoic Bladder

Reproductive System - MALE

Allantoic Bladder Spermatic Cord Penis testes Spermatic Cord Epididymis testes Epididymis

Reproductive System - FEMALE

Uterine Horn Uterine Horn Ovary Ovary Uterine Body Allantoic Bladder

Cardiovascular System – Heart & Spleen

heart Spleen

Cardiovascular System – page 418 – –

1 PINK common carotid artery

on each side

2 BLUE jugular veins

on each side • These are the

internal and external jugular veins Common Carotid Artery Internal Jugular Vein External Jugular Vein

Cardiovascular System: Superior Vena Cava, Pulmonary Trunk & Aortic Arch

Superior Vena Cava Aortic Arch Pulmonary Trunk Right Lung Left Lung

Cardiovascular System: Inferior Vena Cava & Abdominal Aorta

Inferior Vena Cava Mesentery Small Intestine Abdominal Aorta Rectum

Ready to clean up?

• Cut off strings – throw away in

GREEN

trash.

• Throw any

PIG TISSUE WASTE

in the

RED

trash • Rinse pig under water and clean both external and internal areas.

• Spray pig with cavicide (in white spray bottle) inside and out!

• Put pig in your saved plastic bag and secure with rubber band. • Write the pig’s name (or group name) on the bag in permanent marker.

– Place bagged pig in the tray.

• Spray down your table with cavicide or simple green!