Ib Biology HL - Transport B2.3

what gets transported by respiratory system

• water

• glucose

• haemoglobin ( oxygen and CO2 )

• Urea

• hormones

• immune cells

• heat<

components of blood

• water ( plasma )

• platelets/ thrombocytes - blood clotting

• erythrocytes - CO2 and O2 transport

• leukocytes ( white blood cells )

arteries

• oxygenated blood

• high pressure

• small lumen thick wall

arteries parts

• inner layer: tunica intima; endothelium ( thin layer of flat cells )

• middle layer: tunica media => withstand high blood pressure. contain thick smooth circular muscles ( vasoconstriction ) and elastic fibers

• tunica externa: tough outer layer made of connective tissue and collagen fiber. can withstand the pressure

veins parts

• inner layer: tunica intima; endothelium ( thin layer of flat cells )

• middle layer: tunica media => withstand high blood pressure

• tunica externa: tough outer layer made of connective tissue and collagen fiber.

• valves: prevent blood from flowing backwards

veins

• deoxygenated blood

• lower blood pressure

• large lumen

• smaller tunica media

• when muscles contract, they exert pressure on them and it allows it to move

capillaries

• low pressure

• large sa

• diameter of only ten micrometers => only one erythrocyte=> blood slows down and allows that more time is present for exchange

• fenestrations in areas where diffusion has to occur really quickly

• thin walls for short diffusion pathway

occlusion of coronary arteries

• can be narrowed or blocked by atheroma, made of lipids such as cholesterol

• restriction of blood flow => increases risk of thrombosis

• if calcium deposits occurs, can harden

• heat attacks