1. Comparative Circulatory System
The function of animal circulatory systems is mainly…
AND…
Transport of O2 to the cells
Transport of CO2 out of the body
Transport of nutrients

2. Two Different Circulatory Systems
Open Circulatory System
Blood (hemolymph) is pumped into open body cavity (hemocoel).
Blood reenters heart through openings (ostia).
Does not require much energy to operate, but can’t sustain high levels of activity.
Closed Circulatory System
Blood is contained within blood vessels:
Arteries move blood away from the heart.
Veins move blood toward the heart.
Energetically costly to operate, but allows higher levels of activity.

3. Invertebrate Circulatory Systems
Most Invertebrates have an open circulatory system.

4. Fish Circulation
A fish heart has two chambers, one atrium and one ventricle.
“Single-loop circulation” results in lower blood pressure in the body capillaries
Heart pumps blood to the gills to be re-oxygenated (gill circulation) after which blood flows to rest of body and back to the heart in one circuit.

5. Amphibian and Reptile Circulation
Amphibian and Reptilian heart is a “Double-loop circulatory system.”
Advent of lungs resulted in two circulations:
Pulmonary circulation - (Lungs)
Systematic circulation - (Rest of body)
Maintains blood pressure in body capillaries
Oxygen rich and oxygen deficient blood mix in the ventricle.

6. Mammalian and Bird Circulation
Mammals, birds, and crocodiles have four- chambered heart.
right and left atria
right and left ventricles
The right and left ventricles are separated by a muscular wall called the septum
This prevents oxygen rich and oxygen deficient blood from mixing
Made up of two pumping systems/circuits.
Pulmonary circulation
Systemic circulation

7. Comparison of Vertebrate Hearts

8. The Human Circulatory System
Functions:
Transports gases, nutrients, hormones, and waste
Regulate body temperature
Fight infection
Major Organs:
Heart
Blood vessels

9. Circulation through body Heart pumps blood
Pulmonary circulation (heart to lungs to heart)
Systemic Circulation (heart to body to heart)
Circulation through heart
Vena Cava
Right atria
Right ventricle
Pulmonary artery
Lungs
Pulmonary vein
Left atria
Left ventricle
Aorta
Body

11. Unoxygenated blood enters the atrium on the right side of the heart.
Unoxygenated blood comes in from the top of the body through the superior vena cava.
Unoxygenated blood comes in from the lower body though the inferior vena cava.

12. While the unoxygenated blood is in the right atrium, the tricuspid valve is closed to keep the blood from flowing down to the ventricle.

13. The atrium contracts and the tricuspid valve opens, forcing the blood down into the ventricle.

14. The tricuspid valve closes again so that blood cannot move back up into the atrium.

15. The ventricle contracts
The ventricle contracts. This forces the unoxygenated blood through the pulmonary valve and into the pulmonary arteries.

16. The right pulmonary artery takes the unoxygenated blood to the right lung.
The left pulmonary artery takes the unoxygenated blood to the left lung.
THE PULMONARY ARTERIES ARE THE ONLY ARTERIES THAT CARRY UNOXYGENEATED BLOOD.

17. Oxygenated blood from the lungs enters the heart through the left atrium.
The mitral valve is closed to keep the blood from going into the ventricle.

18. THE PULMONARY VEINS ARE THE ONLY VEINS THAT CARRY OXYGENATED BLOOD.
Oxygenated blood from the right lung returns to the heart through the right pulmonary vein. Oxygenated blood from the left lung returns to the heart through the left pulmonary vein.
THE PULMONARY VEINS ARE THE ONLY VEINS THAT CARRY OXYGENATED BLOOD.

19. The left atrium contracts
The left atrium contracts. This forces the oxygenated blood through the mitral valve into the left ventricle.

20. The mitral valve closes again
The mitral valve closes again. This keeps the oxygenated blood from moving back up into the atrium.

21. Oxygenated blood is forced into the aorta to be carried to the rest of the body.

22. Blood Vessels Tissues Arteries Veins Capillaries connective
smooth muscle
endothelium (type of epithelial tissue)
Arteries
Veins
Capillaries

23. Blood Blood Plasma Blood Cells 90% water 10 % Connective tissue
dissolved gases
salts
nutrients
enzymes
waste
plasma proteins
transport fatty acids, hormones, vitamins
fight infections
involved in blood clotting
Connective tissue
Fluid structure
(can flow to all parts of the body)
Blood Cells
Red blood cells
lack nuclei
transport oxygen
White blood cells
contain nuclei
fight infection
Platelets
plasma proteins and cell fragments responsible for clotting