chapter 1b Flashcards
(33 cards)
why do veins have valves
to prevent back flow
what are the adaptations of the lungs for efficient gaseous exchange
- alveoli 1 cell thick
- good blood supply
- large surface area
what is diffusion
the flow of particles from a high to low concentration
what is oxyhaemoglobin
when oxygen binds to the haemoglobin
arteries:
- thick walls to cope with high pressure
- thin lumen
- can vasoconstrict and vasodilate to reduce blood flow to non essential organs
- carry blood away from the heart
veins:
- large lumen
- thin walls are the pressure is low
- carry deoxygenated blood to the heart
capillaries:
- link arteries and veins
- 1 cell thick
what are the 4 capillaries of the heart
- vena cava
- pulmonary artery
- pulmonary vein
- aorta
what does the vena cava do
carry deoxygenated blood to right atrium
what does the pulmonary artery do
deoxygenated blood from right ventricle to lungs
what does the pulmonary vein do
carry oxygenated blood from lungs to left atrium
what does aorta do
oxygenated blood from left ventricle to body
why does the left ventricle have a thick wall?
- needs to pump blood at a high pressure
what does systole mean
- to contract and pump out blood
what does diastole mean
- relaxing and filling up with blood
how many phases do the heart beat in
2
whats heart rate
the number of times the heart beats (bpm)
whats stroke volume
volume of blood that the left ventricle ejects with each beat
whats cardiac output
volume of blood that the heart can pump out per minute
whats the equation for cardiac output
stroke volume x heart rate
what happens to the heart during exercise
- heart rate increases
- increase in cardiac output
- anticipatory rise
- stroke volume increase
what is anticipatory rise
body releases adrenaline when expecting physical activity
what is inhaling
breathing in air by increasing the volume of the chest cavity
what muscles contract during inspiration
- intercostal muscles
- diaphragm
