Blood Vessels Flashcards
3 types of blood vessels
Arteries
Capillaries
Veins
Structures of arteries
Thick muscular wall
Elastic walls
Small internal lumen
Structure of capillaries
Very thin walls (1 wall thin)
Small internal lumen
Structure of veins
Thin walls
Contain valves
Large internal lumen
Functions of arteries
Carries blood at high pressure away from the heart
Mainly carry oxygenated blood
Except pulmonary artery which carries deoxygenated blood to lungs from heart
Functions of capillaries
Link smaller arteries to smaller veins
Carry blood at very low pressure
Functions of veins
Carry blood at low pressure towards heart
Mainly carry deoxygenated blood
Except pulmonary vein which varies oxygenated blood from lungs to heart
Relevance of arteries
Blood pressure increases during exercise as working muscles demand more o2, increasing blood flow
Muscles in artery wall contract and relax automatically
Muscles Relax - dilate for blood to travel, regulate blood pressure
Relevance of capillaries
Allows gaseous exchange
Walls very thin to allow gases and nutrients to pass through them therefore getting oxygen to the muscles
Removing co2
Relevance of veins
Carry deoxygenated blood from muscles
Wide internal diameter allows blood to bass through more easily
valves help return blood to heart and prevent back flow due to low pressure
State type of blood vessel that hold blood at high pressure
Arteries
What is vascular shunting
Redistribution of blood flow
Blood is diverted from inactive areas to the working muscles
What is vasoconstriction
Blood vessels constrict - made smaller
During exercise, chemical changes trigger signals from your nervous system
Signals cause blood vessels that supply the inactive areas to restrict reducing blood flow to these areas
Eg digestive system
What is vasodilation
Blood vessels dilate to make them bigger
Chemical reaction are trigger signals during exercise from nervous system
Blood vessels supplying to active areas to dilate thus increasing blood flow to these areas
These working muscles need more oxygen and nutrients