The document compares and contrasts the circulatory systems of fish, reptiles, and mammals. It notes that all three have at least one atrium and one ventricle, and valves to prevent backflow. However, fish have a single loop circulation with mixed blood, reptiles have a double loop circulation with some mixing of oxygenated and deoxygenated blood, and mammals have a complete separation of blood types with a double loop circulation. The document also provides an overview of the main types of blood cells and their functions.

1. Circulatory
system

2. Heart of fishes
atrium
Sinus
venosus
Bulbus arteriosus
Ventricle

3. Heart of reptiles
Right
atrium
Left
atrium
Ventricles

4. Heart of mammals
Sup.vena
cava
Right atrium
Aorta
Pulmonary
arteries
Pulmonary
veins
Left atrium
Right ventricle
Left ventricle
Inf.vena
cava

5. Similarities
All of them are close circulation
Have atrium and ventricle
Have valves to prevent back-flow

6. Differences
Fishes
Reptiles
• An atrium and a
ventricle
• Single loop
circulation
• No separation
between
oxygenated and
deoxygenated
blood
• No septum
• 2 atrium and
single
partitioned
ventricle
• Double loop
circulation
• There is
separation and
mixed of
oxygenated and
deoxygenated
blood
• Incomplete
septum
Mammals
• 2 atria and 2
ventricles
• Double loop
circulation
• Oxygenated
and
deoxygenated
blood are
separated
• Has a complete
septum

7. Blood cells
Erythrocytes
Lymphocytes
Macrophages
Storage and
transport
oxygen
B cells secrete
antibodies
Destroy foreign
particles and
dead or dying
cells
Granulocytes
Eosinophil kill
parasites and
involve in
allergic reaction
Killer T cells kill
foreign bodies
Basophil kill
foreign particles
Helper T cells
help activate
other
lymphocytes
Neutrophil
engulf foreign
bodies and
damaged cells
Thrombocytes
Play a key role in
blood clotting