Cardiovascular System Flashcards
How does blood enter the heart in insects?
Through Ostia
What is an open circulatory system?
Where the animals muscles are bathed in fluid e.g insects, molluscs, crayfish
What is a closed circulatory system?
The arteries, veins and pumping system are all linked together
If blood is pumped one way it must come back another way
Describe elements of the vertebrate cardiovascular system
A muscular heart pumps blood around the body
They have an arterial and venous system connected to the heart
What does the arterial system do?
Transports materials to the tissues e.g O2 and has high pressure
What does the venous system do?
Removes waste materials from the tissues e.g CO2 and has low pressure
What is systemic circulation?
To and from the body tissues: high pressure
What is pulmonary circulation?
To and from the lungs: has to be low pressure
What holds the majority of the blood?
The veins
How do you change blood flow?
Alter the pressure or the resistance
What is vasoconstriction?
Blood vessel decreases in diameter
What is vasodilation?
Blood vessel increases in diameter
What are the four chambers of the fish heart?
Sinus venosus: collects blood from rest of body
Atrium: takes the blood and moves it to ventricle
Ventricle: pumps blood to conus arteriosus
Conus arteriosus: reduces the pressure generated by ventricle
Describe elements of the amphibian heart
Heart has three chambers (2 atria and one ventricle)
Spiral valve doesn’t completely separate oxygenated blood in ventricle= mixing
What is the Foramen of Panizza?
Valve between the aortic trunks to divert blood
When the heart pumps the valve is closed
