blood and heart vessels Flashcards
open circulatory system
blood leaves blood vessels and flows around the cells of the animals body before re-entering blood vessels again
closed circulatory system
blood remains in a continuous system of blood vessels
why is closed circulatory system more efficient
blood can be pumped around the body faster allowing nutrients and oxygen to be distributed faster to cells
allows the flow of the blood to different organs to be increased or decreased
deoxygenated blood flow
enters heart through vena cava and enters the right atrium chamber contracts and forces blood down through the tricuspid valve vena cava closes and blood enters thefight ventricle the chamber contracts and tricupsid valve closes blood is forced out of heart to the lungs through the semilunar valve in pulmomonary artery
oxygenated blood flow in heart
enters left atrium through pulmonary vein and is pumped down bicuspid valve to left ventricle
chamber contracts bicuspid valve closes and pumped out of the body through semilunar valve in the aorta
control of heartbeat
-SA node pulses and causes atria
to contract
-electrical impulses from the pacemaker (SA node) stimulates the AV node
-AV node sends impulses down special fibres located in the septum
-the impulse is passed out to walls of the vetricles by thin fibres this impulse causes the ventricles to contract
pulse
alternate expansion and contraction of the arteries
blood pressure
the force exerted by the blood against the walls of the arteries
effects on circulatory system
exercise
fat
smoking
smoking
increases heart rate and raises blood pressure
tobacco smoke increases the likelihood of blood clots in blood vessels and lung cancer
fat
fats are high in cholesterol
cholesterol increases the risk of developing blockages in arteries especially coronary arteries and brain- which can lead to strokes or heart attacks
exercise
strengthens and enlarges heart
it improves circulation and helps reduce body fat
