Heart Dissection, Lab Report Guide

8/11/2019 Heart Dissection, Lab Report Guide

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Year 10 Pre-Diploma Biology

Heart Dissection

IntroductionThis lab practical allows you to identify and compare the size, shape and tissue type of themajor chambers and vessels of the heart. The goal of the lab is not just to observe anatomy,

but to associate structure with function. The heart is apumpfor blood that comesinto the right atrium, goes out to the lungs through the right ventricle, returns through theleft atrium, and leaves again through the left ventricle - a double circulation. Each chamberis separated by valvesthat prevent the backflow of blood. Try and figure out where the

various components are, how each works, especially how the shape, composition, and eventexture of each part contribute to its function.

Preliminary Questions! "hat is the heart#s surface like$ "hat function do you think this serves$

%! &ow does the heart muscle itself receive oxygen for respiration$

Observation: External AnatomyDO NO !" AN#$IN% #E&As you follow the instructions and find each structure, label a pin and stick the pin in thestructure. I must see all 10 structures before you may continue to the internal structures.

. 'dentify the right and left sides of the heart. (ook closely and on one side you will see adiagonal line of blood vessels that divide the heart. The half that includes all of the apex)pointed end! of the heart is the left side. *onfirm this by s+ueezing each half of the heart.The left half will feel much firmer and more muscular than the right side.

%. Turn the heart so that the right side is on your right, as if it were in your body. ind thelarge opening at the top of the heart next to the right auricle )flap of darker tissue on top ofthe heart!. This is the opening to the su'erior vena cava,which brings blood from thetop half of the body )arms and head! to the ri(ht atrium) *arefully stick a glass rod down

this vessel. ou should feel it open into the right atrium. little down and to the left of thesuperior vena cava there is another blood vessel opening. This is the inferior vena cava*which also leads to the right atrium, bringing blood from the lower tissues )legs and

Year 10 2014-2015 Pre-Diploma Biology Unit 1: CVD, Heart Dissection !i"e

+aterials/issection kit - scissors, scalpel, forceps, etc/rawing pencils and0or /igital *amera 1ubber0latex gloves/issection guide and results table 2ig or sheep &eart

/iagram of heart /issection board/issection pins 3lass rod


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abdomen!. ou can also see another blood vessel next to the left auricle. This is a'ulmonary veinthat brings blood from the lungs into the left atrium.

4. 5ticking straight up from the centre of the heart is the most muscular blood vessel youwill see. This is the aorta, which takes oxygenated blood from the left ventricleto therest of the body )the ventricles are the lower chambers of the heart!. The aorta branchesinto more than one artery right after it leaves the heart, so it may have more than oneopening on your heart specimen. (ook carefully at the openings and you should be able tosee that they are connected to each other.

6. 7ehind and to the left of the aorta there is another large vessel. This is the 'ulmonaryarterywhich takes blood from the ri(ht ventricleto the lungs.

Draw simple, coloured views of the front (ventral) and a back (dorsal) eternal of theheart.

8entral 8iew /orsal 8iew

Dissection: Internal Anatomy

orta2ulmonary artery

The two vena cava go intothe right atrium on theother )dorsal! side

The pulmonary vein goesinto the left atrium on thedorsal side.

*oronary artery and vein

"hen you need to seeinside the right ventricle,cut here.

"hen you want to open

the left ventricle cut here.



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. 'nsert your dissecting scissors or scalpel into the su'erior vena cavaand make anincision down through the wall of the ri(ht atriumand ri(htventricle. 2ull the twosides apart and look for three flaps of membrane. These membranes form the tricus'idvalvebetween the right atrium and the right ventricle. The membranes are connected toflaps of muscle called the papillary muscles by tendons called the chordae tendinaeor9heartstrings.9 This valve allows blood to enter the ventricle from the atrium, but prevents

backflow from the ventricle into the atrium.

!ake observations and measurements of as many structures as you can, fillin" in yourresults table.

%. 'nsert a glass rod into the 'ulmonary arteryand see it come through to the rightventricle. :ake an incision down through this artery and look inside it for three smallmembranous pockets. These form the 'ulmonary semi,lunar valveswhich prevent

blood from flowing back into the right ventricle.

4. 'nsert your dissecting scissors or scalpel into the left auricle at the base of the aortaand

make an incision down through the wall of the left atriumandventricle, as shown bythe dotted line in the external heart picture. (ocate the mitral valve )orbicus'id valve!between the left atrium and ventricle. This will have two flaps of membrane connected topapillary muscles by tendons.

!ake observations and measurements of as many structures as you can, fillin" in yourresults table.

6. 'nsert a glass rod into the aorta and observe where it connects to the left ventricle. :akean incision up through the aorta and examine the inside carefully for three smallmembranous pockets. These form the aortic semi,lunar valvewhich prevents blood

from flowing back into the left ventricle.

At this point make sure your chart is complete with measurements and observations.

Also, make sure to draw or photo"raph each view so you can include ima"es in the labreport showin" the structures in the table.'nclude all other drawings of the internal heart structures here, stating from which side theheart is being seen and labelling all identified structures.



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$eart Dissection -esults ableill out as much of the table below as you can. 5ome boxes may not be relevant.;bservations should include colour, texture, shape, and anything else interesting to you.

.tructure Diameter/mm0

1allhic2ness

/mm0

Observations

8ena *ava

1ighttrium

(arge)Tricuspid!

valve

1ight8entricle

5emi-lunarvalves

2ulmonaryrtery

2ulmonary8ein

(efttrium

(arge)7icuspid!

valve

(eft8entricle

5emi-lunar

valves

orta

*oronaryrtery and

8ein



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$eart Dissection 3ab -e'ortour lab report should consist of

. brief Introductionto what you did and what the purpose of the lab was. "hatwas the +uestion you were trying to answer, or what were the goals of the lab$ 7esure to specify the animal from which your heart came.

%. -esultssection that includes text and drawings0photos of the steps of thedissection. 'n the photos, label the structures of interest. Each drawing0photo musthave a caption. lso include in this section your completed tables of measurementsand observations.

4. Discussionsection in which you select onemajor anatomical feature of theheart, e.".,the tricuspid valve )valve! or the left ventricle )chamber! or the aorta)vessel!, and discuss how its function is related to its structure. eatures you mightinclude in this description are the shape, the composition and mechanicalproperties of the tissue, and the texture of any surfaces involved. #rovide evidence

from your observations, preferably numerical, for everythin" you claim.

ASSESSMENT

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Heart Dissection, Lab Report Guide