All of SB5 Flashcards
(13 cards)
Disadvantage of single circulatory system
(for fish)
Blood loses pressure as it passes through gills before reaching organs. Blood travels to organs slowly.
Cannot supply oxygen quickly
Advantage of double circulatory system
Blood passes through heart twice
Travels rapidly to body cells, providing enough oxygen
How does blood flow into the heart?
Through the vena cava (deoxygenated) and pulmonary vein (oxygenated)
(at the same time)
Blood entering the heart through vena cava ( from body cells) enters the?
Right atrium
Blood flowing in pulmonary vein (from lungs) enters the
left atrium
The two atria contract together and?
Push blood into the ventricles
After blood reaches the ventricles?
The ventricles contract and push blood out of heart through the pulmonary artery (right side) and aorta (left side)
Deoxygenated blood flows from right ventricle and out of the heart (to lungs) through the
Pulmonary artery
Oxygenated blood flows from left ventricle and out of the heart (to cells) through the
Aorta
Cells found in right atrium that keeps heartbeat steady?
Pacemaker cells; produce small electrical impulses; spread thru muscular walls; heart contracts
Small arteries that branch off aorta and supply heart with oxygen?
Coronary arteries
Why are closed systems better
Prevents accumulation of waste substances in body
Efficient exchange of substances
Meaning of systole
Refers to contraction phase of heart
