Cardiovascular and
Respiratory Lab
Dissection Protocol and mini-lab
outline
Dissection Instructions for Gross
Anatomy
1.
Make an incision with your scalpel three inches below
the vibrissae on the ventral surface.
2. Cut through the muscle layers with the scalpel in a
straight line down the sagittal plane to a point one inch
anterior to the umbilicus (cut 1 on next slide).
3. Go back with the scissors and cut through the
sternum.
4. At the area parallel with the forearms cut on the
horizontal or transverse plane to the peripheral trunk.
Follow the same procedure at the level of the
diaphragm (cut 3 on next slide).
Stop – Observe – Draw Ventral Thoracic cavity in situ and
label all visible structures. Note observations below
your drawing.
Notes on Gross Anatomy
• Under your drawing make the following
observations.
– How is the heart oriented?
– Is there a difference in the right and left lung?
– Where is the diaphragm? Is it attached to
anything?
– Other than the heart and lungs can you locate
any additional structures? If so label them on
your diagram and indicate with a star.
Heart and Lung Removal
1.Carefully locate the top of the thoracic cavity. Locate the
larynx with your finger. Gently remove the remaining
muscle and glandular tissue from the larynx and follow it
down clearing the top of the trachea as well.
2. Once you can clearly see the full respiratory tract, make
an incision at the top of your larynx and begin removing
the respiratory system and heart from the pig.
3. When removed, you can put your pig back in the bucket,
but you will need to keep the removed organs in your
pan.
4. Draw the removed organs in both a dorsal and ventral
view labeling all identifiable parts on the lungs, heart and
respiratory passages. Based on what you are seeing
and feeling create predictions about the types of
histology that exist in the following structures that may
support the functions: Larynx, trachea, lungs, veins,
arteries, heart.
Dissection of the Heart
1.If the pericardial membrane is still intact, remove
it from the heart. Use a teasing needle and
forceps carefully dissect the heart away from the
rest of the viscera. The arteries will appear red
and the veins blue because the pig has been
double injected with latex.
2.Carefully remove the heart by cutting the arteries
and veins. Try to leave some short pieces
attached to the heart.
Observations of Blood Supply
• Observe the orientation of the blood supply
coming into and leaving the heart.
• Draw the removed heart in the ventral and
dorsal view. This is a form of observation/data
for biological sciences. This will allow you to
follow blood supply. You should designate
blood vessels with a B or R to indicate color of
the latex within.
• Label: Superior and Inferior vena cava, rt.& lf.
Atria, rt. & lf. Ventricle, Cardiac veins, Coronary
arteries, Pulmonary arch, Aortic arch, rt. & lf.
Pulmonary arteries and veins.
Dissection Instructions for Gross
Anatomy Internal
•
•
•
Cut the heart in half along the frontal plane into dorsal
and ventral halves.
Draw both halves. Identify and label the following
structures: Rt. and Lf. Atria, Rt. and Lf. Ventricles,
Tricuspid valve, Bicuspid (mitral) valve, Pulmonary
trunk, Aorta, Vena Cava (inferior and superior),
Interatrial septum, interventricular septum.
Reflect below your drawing. Are you seeing a clear
separation of colors from the injection of latex? In
other words, is there one side that is blue and another
red? If not, why might this be the case. How does
fetal and adult circulation differ?
Respiratory System
• Now that the heart is removed you should
see the full respiratory system. Draw the
removed organs in a dorsal and ventral
drawing labeling: Larynx, Trachea, Right
and Left Primary Bronchi, Rt. And Lf.
Cardiac Lobe, Rt. And Lf. Diaphragmatic
Lobes, Rt. Apical Lobe, Rt. Intermediate
Lobe, and the Diaphragm.
Structure Dissections:
• Larynx: observe the epiglottis. Draw it
(superior view) at the top of the larynx
(glottis) and esophagus and label all three
pieces.
Your final Cardiovascular/Respiratory Lab Observations should
Include:
1 In situ drawing of both systems with additional structures and observations
1 ventral view of the removed organs with labels and observations
1 dorsal view of the removed organs with labels and observations
1 dorsal and 1 ventral view of external heart with blood flow indications
1 internal drawing of both halves of sectioned heart with observations
1 dorsal view of the respiratory structures
1 ventral view of the respiratory structures
1 superior view of the larynx
Drawings will be assessed on the Lab Drawing Rubric.