heart and blood Flashcards
what is the heart?
an organ that pumps blood around the body
what is the purpose of the circulatory system?
to carry oxygen and nutrients to every cell and remove waste
where does deoxygenated blood go?
right atrium - right ventricle - lungs
where does oxygenated blood go?
left atrium - left ventricle - whole body
why is the double circulatory system important?
it makes the circulatory system more efficient
how many chambers does the heart have and what are they called.
- right atrium, left atrium, right ventricle, left ventricle
why is the muscle wall on the left ventricle thicker?
it has to pump blood at a high pressure around the whole body
what are the 4 main blood vessels associated with the heart?
- vena cava
- pulmonary vein
- aorta
- pulmonary artery
vena cava (right)
carries deoxygenated blood from the body to the heart
pulmonary vein (left)
carries oxygenated blood from the lungs to the heart
aorta (left)
carries oxygenated blood from the heart to the body
pulmonary artery (right)
carries deoxygenated blood from the heart to lungs
what is the purpose of valves?
prevent back-flow of blood
what is the purpose of coronary arteries?
branch of aorta and supplying the heart with its own oxygenated blood
process of blood flow through the blood
1) blood enters the right atrium (via vena cava) and left atrium (via pulmonary vein)
2) atria walls contracts, forcing blood into the ventricles. the valves to shut
3) the ventricles contract,
blood in the right ventricle - pulmonary vein (to lungs)
blood in the left ventricle - aorta (to body)
what is the approximate value for resting heart rate?
70 beats per min
what are pacemakers?
a group of cells controlling heart rate
where are pacemakers found?
right atrium
how do pacemakers work?
they provide electrical impulses which spread through muscle cells causing them to contract
how can an abnormal heart rhythm be treated?
artificial pacemaker.
send our electrical signals to correct the heart rhythm.
implants - under the skin, wire connected to the heart
what are the 3 types of blood vessels?
arteries
veins
capillaries
how are arteries adapted for their function?
1) carry blood away from the heart
2) thick muscle layer - adds strength to resist high pressure of blood
3) thick elastic layer - allows arteries to stretch and recoil
how are veins adapted for their function?
1) carry blood towards the heart
2) wide lumen - enables low pressure
3) valves - prevent back-flow of blood
how are capillaries adapted for their function?
1) exchange nutrients and oxygen
2) walls are one cell thick - short path for diffusion
3) permeable walls - substances can diffuse across
4) narrow lumen - blood moves slowly - more time for diffusion
