Comparative Heart Anatomy

Question 1

Name the circulation pattern of mammals & reptiles

Answer 1

Double circulation

blood passes through heart twice

Question 2

Name the circulation pattern of fish

Answer 2

single circulation

Question 3

How many chambers does a mammalian heart have?

Answer 3

4 chambers

Question 4

Ruminants & horses have a larger right lung. What affect does this have on the heart?

Answer 4

Displaces 60% of heart to left of mid-line

Question 5

Where is the heart located?

Answer 5

lower ventral part of mediastinum

Question 6

Most of the horses heart surface is covered by?

Answer 6

the lungs

Question 7

Why is the CV system of the horse superior?

Answer 7

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

Question 8

Ascending aorta curves to the …. in birds and the …. in mammals

Answer 8

right in birds

left in mammals

Question 9

The avian heart lacks…? And apex is surrounded by…?

Answer 9

lacks diaphragm & chordae tendinae

Apex surrounded by liver lobes

Question 10

How many pulmonary veins do mammals have compared to birds?

Answer 10

Mammals have 4-6

Birds (chicken specifically) have 2

Question 11

Cranial vena cava enters right atrium as one major vessel in mammals.
What is the difference in a chicken?

Answer 11

enters right atrium as two seperate vessels: R & L cranial venae cavae

Question 12

Which heart is larger relative to size & body mass, mammal or avian?

Answer 12

Avian

Question 13

A bit about the fish heart

Answer 13

One atrium
One ventricle
Single circulation
2 chambered

Question 14

A bit about the reptile/amphibian heart

Answer 14

Two atria
One ventricle, partially divided
Double circulation 
-oxygenated & deoxygenated blood are MIXED
3 chambered heart

Question 15

A bit about the mammalian heart

Answer 15

Two atria
Two ventricles
Double 
-oxygenated & deoxygenated blood are SEPERATE
4 chambered heart

Question 16

Draw the blood flow through the lizard, snake & turtle heart diagrams.

Answer 16

DO IT SHITHEAD

Question 17

What is special about the crocodilian heart? Describe.

Answer 17

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

Question 18

What is Ventricular Septal Defect (VSD)?

Answer 18

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

Question 19

List the classifications of VSD

Answer 19

1. Perimembranous
2. Inlet
3. Subarterial or subpulmonary
4. Muscular

Question 20

What are the effects of VSD?

Answer 20

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

Question 21

Clinical signs of VSD?

Answer 21

Cyanosis (lack of O2)
Heart murmur (regurgitant)

Question 22

What is tetralogy of fallot?

Answer 22

complex combination of 4 heart defects:

• VSD
• Pulmonary stenosis (low blood flow to lungs)
• R-ventricular hypertrophy
• Overriding aorta

Question 23

Clinical signs of TOF?

Answer 23

cyanosis
poor growth
exercise intolerance
loud heart murmur

Question 24

What are the two main functions of cardiac toxins?

Answer 24

To capture prey

To serve as defence

Question 25

What are the effects of cardiac glycosides?

Answer 25

inhibit Na/K ATPase pump

stimulate release of Ca from sarcolemma causes contractions

Question 26

What are the effects of plant cardiac poisons?

Answer 26

arrhythmia (irregular heart beat)
bradycardia (slow HB)
tachycardia (increased HB)
salivating, cold extremities, dilated pupils