The Circulatory System Flashcards
What kind of circulatory system do mammals have?
closed= the blood remains within the blood vessels
double = blood passes through the heart twice in each circuit - there is one circuit which delivers blood to the lungs and another which delivers blood to the rest of the body
What is the function of the circulatory system?
multicellular organisms like mammals have low SA:Vol so they need this specialised mass transport system to carry raw materials from specialised exchange organs to their body cells
- transport nutrients = Oxygen, glucose amino acids
-transport waste products = carbon dioxide, heat
- blood transports metabolic wastes, respiratory gases, digestion products and hormones
What is the function of the hepatic portal vein?
carries digested food from intestines to the liver
What is the function of the renal vein?
carries deoxygenated blood from the kidneys to the vena cava
What is the function of the renal artery?
carries oxygenated blood from the body to the kidneys
What blood vessel carries blood at lowest pressure?
vena cava
What is the function of the hepatic vein?
carries blood from the liver to the vena cava
What is the function of the hepatic artery?
carries blood from the aorta to the liver
What pressure does the blood flow through the lungs and why?
lower pressure to prevent damage to the capillaries in the alveoli and reduce speed of blood flow to allow more time for gas exchange
What happens to the blood after the lungs?
oxygenated blood from the lungs then goes through the heart to be pumped out at a higher pressure to the rest of the body to ensure the blood reaches all respiring cells
In terms of pressure, which way does the blood flow?
blood always flows from higher to lower pressure in the circulatory system and as the vena cava is the last blood vessel that takes blood to the heart from the body it is at its lowest pressure
