The heart and blood vessels Flashcards
Name types of circulatory systems
Open circulatory system and closed circulatory system
Open circulatory system
Heart pumps blood into open ended vessels, e.g. insects
Close circulatory system
Blood remains in a continuous system of blood vessels, e.g. humans
advantages of a closed circulatory system
blood can be pumped faster
-Nutrients can be delivered to cells quicker
-Allows organisms to be more active
Blood flow rate to different organs can be changed
-E.g. increased blood flow to leg muscles when running
Name blood vessels
Arteries, veins, capillaries
Arteries
Carry blood away from the heart
What are smaller arteries called?
Arterioles
Veins
Carry blood to heart
What are smaller veins called?
venules
Capillaries
tiny vessels that link arteries and veins
blood vessels differences (lumen)
artery - small
Vein - large
Capillaries - tiny
blood vessels differences (wall)
Artery - thick
Vein - thin
Capillary - thin (allows easy exchange of materials)
blood vessels differences (valves)
artery - none
Vein - present
Capillary - none
blood vessels differences (direction of blood flow)
Artery- away from heart
vein - to the heart
Capillary - links arteries and veins
blood vessels differences (oxygenation of blood)
arteries - oxygenated (except pulmonary artery)
veins - deoxygenated (except pulmonary vein )
capillaries -both
blood vessels differences (blood flow)
artery - rapid under high pressure
vein - slow under low pressure
capillary - slow, pressure falling (allowed time for material exchange to occur)
blood vessels differences (pulse)
artery - blood flows in pulses
vein - blood flows at steady rate
capillary - no pulse
order of relationship between blood vessels
Artery
Arteriole
Capillary
Venule
Vein
material exchange is facilitated by?
Thin walls - rapid entry/exit of materials
Large surface area - close contact with body cells
Narrow tubes - increases pressure
Blood flow in arteries has aided by?
thick, muscular layer - increases blood flow
elastic fibres - bring blood vessel back to shape
Location of the heart
Thoracic cavity - between lungs, above, diaphragm