Largesurfaceareatovolumeratio to increaserate of diffusion and rate of absorption
Capillariesprovide the villi with a goodbloodstreamgiving it a goodconcentrationgradient for diffusion
villi have a one cell think membrane for a short diffusion distance into the blood
Coronary heart disease
When the coronaryarterieswhichsupplybloodtotheheartmusclestarttogetblockedbythebuildupoflayersoffattymaterial,causingthelumenofthearteriestobecomenarrowersothatlessbloodandoxygencanreachtheheartmuscle
Treatmentsforcoronaryheartdisease
1. Stents
2. Statins
Stent
Anexpandabletubethatcanbeplacedinsidethearteries to hold themopen and ensureblood can keepflowing
Stents advantages and disadvantage
The surgery is relatively quick and they're effective for a long time
There are risks such as inducing a heart attack, infection, or blood clot
Statins
Medications that alterthebalanceofcholesterol in the bloodstream by decreasingbadLDLcholesterolandincreasinggoodHDLcholesterol,loweringtheoverallriskofcoronary heart disease and otherdiseases
Statins advantages and disadvantages
They have to be taken regularly for years
They can cause side effects such as headaches and kidney failure
Faulty heart valves
When the heart valvesgetdamagedorweakened, eithernaturallyovertime or due to otherfactors,causingissues with blood flow
Treatments for faulty heart valves
1. Valvereplacement with biologicalvalves from anotherhumanorpig
2. Valvereplacement with man-mademechanicalvalves
Heart valve replacements cons
Require surgery
Ongoing risk of blood clots
Heart failure
When the heartisn'table to pump bloodaround the bodyproperly
Treatments for heart failure
1. Medications
2. Heart transplant with a biologicalheart from a donor
3. Artificialheart (temporaryfix)
Heart transplants cons
Donor heart may be rejected by the body's immune system
Artificial hearts cons
Not as good as biological hearts, only a temporary fix
Diffusion
Net movement of particles from an area of high concentration to an area of low concentration. It is a passive process
Factors affecting diffusion
-temperature
-surface area
-concentration gradient
Osmosis
Net movement of water molecules across a semi permeable membrane from an area of high water concentration to an area of low water concentration
Active transports
Net movement of particles from an area of low concentration to an area of high concentration using energy from respiration