Topic 1

• 5 importance of circulatory system

  Transport

  Immunity

  Regulating body temperature

  Defence system

  Scabbing
• Definition of mass flow

  transport of substance in the flow of a fluid
• state the purpose of mass flow

  move substances quickly to an area
• does blood flow in one direction or two

  pressure allow blood to flow in a ingle direction
• why many animals need a heart and a circulatory system?

  > heart needed to pump blood around body

  > animal has small SA:V

  > diffusion is not effective

  > high metabolic rate
• medication that reduces the risk of CVD

  >ACE inhibitor

  > Calcium channel blocker

  > Diuretics

  > Statins

  > Anticoagulants

  > Platelets inhibitor
• function of ACE inhibitor

  -> reduces the synthesis of angiotensin II

  -> prevent angiotensin II produced from inactive angiotensin I

  -> reduce vasoconstriction and blood pressure
• what is angiotensin II

  -> hormone

  -> causes vasoconstriction of blood vessels (controlling blood pressure)
• side effect for ACE inhibitor

  -> dry cough

  -> dizziness due to rapid decrease in b.p.

  -> abnormal heart rhythm

  -> reduce kidney function
• other considerations made when prescribing ACE inhibitor

  -> people with kidney disease as the drug may reduce kidney function

  -> people intolerant to ACE inhibitor, alternative drug is prescribed
• function of calcium channel blocker

  -> antihypertensive drug which block Ca channel in muscle cells in lining of arteries

  -> failure of Ca entering cell preventing muscle contraction, so blood vessels don’t contract

  -> reducing b.p.
• side effect of Ca channel blocker

  -> headache

  -> dizziness

  -> swollen ankles due to build up of fluid in blood

  -> abnormal heart rhythm

  -> flushing red in face

  -> constipation
• other considerations made when prescribing Ca channel blocker

  can’t prescribe to people have history with heart attack

  -> will make symptoms worse/ fatal
• diuretics

  -> increase vol. of urine production by kidney

  > by removing excess fluid and salt

  -> decrease blood plasma vol and cardiac output

  > decrease b.p.
• Side effect for diuretics

  > dizziness

  > nausea

  > muscle cramp
• other considerations when prescribing diuretics

  less salt diet, prevent counteract diuretics effect
• statin

  inhibit enzyme involved in LDL cholesterol production
• side effect of statin

  > tiredness

  > disturbed sleep

  > feeling sick

  > vomiting

  > diarrhoea

  > headache

  > muscle tiredness
• anticoagulant

  > reduce blood clotting

  > warfarin = anticoagulant

  > interferes vitamin K production

  > reduce synthesis of blood clot

  > decrease thrombosis, reduce blood vessel being blocked
• platelet inhibitor

  > reduce blood clotting

  > prevent platelets clumping together to prevent formation of blood clot
• Lipoproteins

  > type of cholesterol

  > lipid + protein

  > not soluble

  > combine with protein to be transported around the bloodstream
• LDL

  > low density lipoprotein

  > more lipids than protein

  > triglyceride (saturated) + cholesterol + protein

  > circulate in blood

  > attack to receptors in cell membrane before being absorbed

  > EXCESS LDL overload receptors = TOO MANY LDLs in blood

  > EXCESS cholesterol start to deposit in artery walls
• HDL

  > high density lipoprotein

  > same component as LDL, but MORE PROTEIN

  > triglyceride - UNsaturated

  > HDLs carry cholesterol from body tissue to liver

  > lower blood cholesterol level
• 3 types of apolipoprotein

  > Apolipoprotein (APOA)

  > Apolipoprotein B (APOB)

  > Apolipoprotein E (APOE)
• Apolipoprotein function and formation

  > protein component of lipoprotein

  > formed in liver & intestine

  > stabilising structure of lipoprotein

  > recognising receptors in lipoprotein on the plasma membrane
• Apolipoprotein (APOA)

  > major protein in HDL

  > removal of cholesterol to the liver for excretion

  > mutation in APOA gene = lower HDL level

  > less removal of blood cholesterol

  > causing higher risk to CVD
• Apolipoprotein B (APOB)

  > main protein in LDL

  > help transfer cholesterol from blood to cells

  > mutation in gene = more LDL

  > higher risk to CVD
• Apolipoprotein E (APOE)

  > major protein in HDL

  > very low density lipoprotein

  > helps the removal of excess cholesterol from blood to liver

  > alleles of APOE: E2, E3, E4

  > APOE 4 slows the removal of cholesterol from blood

  > higher risk to CVD
• Saturated fat

  > max. no. of H atoms

  > no C=C

  > animal fat

  > straight chain

  > solid in room temp
• unsaturated fat

  > monounsaturated, one C=C

  > polyunsaturated, lots of C=C

  > fewer H atoms than saturated

  > kinks in chain

  > prevent chains packing closely together

  > liquid in room temp

  > vegetable/ fish oil/ nuts
• cholesterol

  > short lipid molecules

  > can be found in cell membrane

  > use to make steroid, sex hormone and growth hormone

  > made in liver and from diet

  > make some of the component in the bile
• 3 types of polysaccharides

  starch, glycogen, cellulose
• starch

  > only in plants

  > a-glycose which forms amylose and amylopectin

  > branch more susceptible to be broken down which glucose utilizes ASAP
• amylose

  > compact

  -> store better

  -> insoluble

  > straight chain

  > 1,4 glycosidic link

  > spiral shape

  > no branch
• amylopectin

  > polymer of glucose with side branches

  > 1,4 and 1,6 glycosidic link
• cellulose

  > plant cell wall

  > straight chain, no branches (1.4 glycosidic bond)

  > b-glycose
• glycogen

  > storage of polysaccharide in animal, fungi, bacteria

  > made of a-glycose

  > branches - release energy easily

  > 1,4 and 1,6 bond

  > in muscle cells/ high metabolic cells

  > more branches than starch
• 1,4 glycosidic bond

  straight chain
• 1,6 glycosidic bond

  branches
• monosaccharides

  glucose, fructose, galactose