Comparative Heart Anatomy Flashcards
Name the circulation pattern of mammals & reptiles
Double circulation
blood passes through heart twice
Name the circulation pattern of fish
single circulation
How many chambers does a mammalian heart have?
4 chambers
Ruminants & horses have a larger right lung. What affect does this have on the heart?
Displaces 60% of heart to left of mid-line
Where is the heart located?
lower ventral part of mediastinum
Most of the horses heart surface is covered by?
the lungs
Why is the CV system of the horse superior?
due to proportionately larger heart & spleen per unit body mass than other large animals
able to double pack splenic red cell volume & oxygen delivery during exercise
Ascending aorta curves to the …. in birds and the …. in mammals
right in birds
left in mammals
The avian heart lacks…? And apex is surrounded by…?
lacks diaphragm & chordae tendinae
Apex surrounded by liver lobes
How many pulmonary veins do mammals have compared to birds?
Mammals have 4-6
Birds (chicken specifically) have 2
Cranial vena cava enters right atrium as one major vessel in mammals.
What is the difference in a chicken?
enters right atrium as two seperate vessels: R & L cranial venae cavae
Which heart is larger relative to size & body mass, mammal or avian?
Avian
A bit about the fish heart
One atrium
One ventricle
Single circulation
2 chambered
A bit about the reptile/amphibian heart
Two atria One ventricle, partially divided Double circulation -oxygenated & deoxygenated blood are MIXED 3 chambered heart
A bit about the mammalian heart
Two atria Two ventricles Double -oxygenated & deoxygenated blood are SEPERATE 4 chambered heart
Draw the blood flow through the lizard, snake & turtle heart diagrams.
DO IT SHITHEAD
What is special about the crocodilian heart? Describe.
4 chambered (reptiles 3) -oxygenated & dexoygenated blood kept seperate
Pulmonary bypass shunt (reptiles also have this)
-enables crocodiles to match lung perfusion to oxygen requirements as they dive
What is Ventricular Septal Defect (VSD)?
Hole in heart (septum)
one of most common defects in sheep, cattle, horses.
Position of defect determined by which parts failed to form in utero
List the classifications of VSD
- Perimembranous
- Inlet
- Subarterial or subpulmonary
- Muscular
What are the effects of VSD?
L-R shunt of blood through VSD
hypertrophy of L & R ventricle
-can lead to shunt reversal causing system hypoxia (inadequate O2) as venous blood enters systemic circulation
Clinical signs of VSD?
Cyanosis (lack of O2) Heart murmur (regurgitant)
What is tetralogy of fallot?
complex combination of 4 heart defects:
- VSD
- Pulmonary stenosis (low blood flow to lungs)
- R-ventricular hypertrophy
- Overriding aorta
Clinical signs of TOF?
cyanosis
poor growth
exercise intolerance
loud heart murmur
What are the two main functions of cardiac toxins?
To capture prey
To serve as defence
