heart, valves, blood Flashcards
what is the heart
an organ consisting of muscle tissue
what are the heart’s 4 chambers
left ventricle, right ventricle, left atrium, right atrium
how are the atria and ventricles separated
by the valves
stage 1
deoxegynated blood from the vena cava flows into the right atrium
stage 2
the blood passes through the tricuspid valve and goes into the right ventricle
stage 3
blood is pumped out of the rv and flows into the pulmonary artery
staage 4
the pulmonary artery sends the blood to the lungs to oxygenate it
stage 5
the lungs transport the blood to the pulmonary vein which sends it to the left atrium
stage 6
the blood passes through the bicuspid valve into the left ventricle, the blood is passed onto the aorta which transports the rest of the blood to the body
what pressue does the artery carry blood at to the organs
the artery carries blood at high pressure to the organs
how do the arteries withstand high pressure
they have thick muscular walls
what happens during blood sruges with arteries
elastic fibres stretch when blood surge passes then recoils inbetween surges
how is the artery’s lumen
narrow
how are the capillary’s walls and why
very thin walls so diffusion path is short
how thick is the capillary
one cell thick
how is the capillary’s lumen
wide lumen
how is the vein’s walls why
thin due to low pressure
what do veins contain and why
contains valves so blood stops flowing backwards
when do the valves open in veins
valve opens when blood flows through correct direction so blood flows through
in veins what happens when blood flows backwards
valves shut
how is the vein’s lumen
wide
what are the parts of blood
white blood cell, red blood cell, plasma, platelets
what 3 things does blood plasma transport
digestion products like glucose from si to other organs
co2 from the organs to the lungs to be breathed out
the waste product urea from the liver to the kidney to be excreted from the urine
what do red blood cells do
transport oxygen from the lungs to the body cells
adap 1 rbc: ha-
rbcs contain haemoglobin, an oxygen carrying molecule which combines with oxygen in the lungs to form oxyhaemoglobin
what does oxyhaemoglobin do
oxyhaemoglobin travels to the organs where it releases the oxygen
adap 2: rbc no n-
rbc has no nucleus so that they have more room for haemoglobin
adap 3: rbc shape
the centre of the cell has dimples
known as biconcave disc
gives rbcs a greater surface area so the oxygen diffuses in and out rapidly
what are platelets
tiny fragments of cells
their job is to help blood clot
