Blood Flashcards
Blood consists of
55% plasma (protein hormones water)
1% white blood cells + platelets
45% red blood cells
Red blood cells
Specialised cell- no nucleus, bioconcave
Red blood cells contain haemoglobin wich transports oxygen
Oxygen binds to heme on haemoglobin molecule
White blood cells
Specialised cells- flexible
Defend against pathogens by engulfing them (phagocytes) break them down with digestive enzymes
OR by producing antibodies (lymphocytes)
which bind to pathogens and neutralise them
Platelets
Small fragments of cells (no nucleus)
Help blood clotting, prevents blood loss and entry of pathogens
Triggered by contact with the damaged cells inside
Plasma
Water with many dissolved substances in it eg albumin antibodies hormones nutrients glucose salts urea fats
Carries dissolved co2, Food substances, urea and hormones
Red blood cells adaptions
No nucleus so more space for haemoglobin
Large surface area bioconcave
Humans have a …. system
Double circulatory system
