B4 organising animals Flashcards
haemoglobin
red pigment in red blood cells that binds to oxygen
plasma
transports blood cells and other substances
waste co2 from cells carried to lungs
urea from liver carried to kidney -removed from blood to urine
soluble products of digestion small intestine -> plasma
white blood cells
some form antibodies against pathogens
form antitoxins
engulf and ingest invading bacteria and viruses
platelets
clot at sites of wounds
stop bleeding out
and bacteria entering body through wound
artery
small lumen
thick walls
thick layer of muscle and fibres
carry blood away from heart to organs
vein
relatively thin walls
large lumen
often have valves- prevent backflow
carry blood from organs to heart
capillaries
walls a single cell thick
tiny vessel with narrow lumen
short diffusion pathway into/ out of blood
double circulatory system
one system carries blood from heart to lungs and back
other carries blood from heart to organs
efficient, receive blood more quickly
atria
where blood enters the heart
top chambers
contract together to force blood into ventricles
vena cava
right atrium
deoxygenated blood from your body
pulmonary vein
left atrium
oxygenated blood from lungs
pulmonary artery
deoxygenated blood comes from right ventricle
aorta
artery
left ventricle pumps oxygenated blood around the body here
ventilating in the lungs
contraction and relaxation of intercostal muscles between ribs and diaphragm
alveoli adaptations for gas exchange
rich supply of capillaries
large surface area - in clusters
short diffusion pathway- one cell thick
steep concentration gradient- blood is low in oxygen, high co2, compared to air in alveoli