Circulatory System / Lifestyle and Disease

Combined notes on circulatory systems and Lifestyle and disease

HideShow resource information
  • Created by: Corrine S
  • Created on: 07-05-13 20:41

Blood Through Heart

Right Side - Deoxygenated Blood

Vena Cava --> R. Atrium --> Atrioventricular Valve --> R. Ventricle --> Semi-Lunar Valve --> Pulmonary Artery --> Lungs

Left Side - Oxygenated Blood

Pulmonary Vein --> L. Atrium --> Atrioventricular Valve --> L. Ventricle --> Semi-Lunar Valve --> Aorta --> Rest of Body

Left ventricle has thicker, muscular wall - better contraction to pump blood round body

1 of 12

Blood Vessels


  • Carry blood away from heart
  • Thick walled, muscular
  • Elastic tissue - withstand high pressure
  • Folded endothelium - expansion


  • Take blood to heart
  • Wide
  • Contains valves - stop blood flowing backwards


  • Smallest vessel
  • Metabolic exchange occurs
  • Capillary beds - increase surface area
  • One cell thick - speeds up diffusion 
2 of 12

Blood Clotting

Thromboplastin ---> Prothrombin ---> Thrombin ---> Fibrinogen --->  Fibrin + Platelets + Red Blood Cells

  • Thromboplastin (protein) released from damaged blood vessel
  • Thromboplastin triggers conversion of prothrombin (soluble protein) into thrombin (enzyme)
  • Thrombin catalyses conversion of fibrinogen (soluble protein) to fibrin (solid insoluble fibres)
  • Fibrin fibres tangle together and form mesh
  • Platelets and red blood cells get trapped - forms blood clot
3 of 12

Atheroma Formation

  • Wall of artery is made up off several layers
  • Endothelium (inner lining) is smooth and unbroken
  • Damage occurs to endothelium (e.g. high blood pressure) = inflammatory response - white blood cells move into area
  • White blood cells and lipids from blood clump together under endothelium
  • form fatty streaks
  • Over time, white blood cells, lipids, connective tissue build up and harden
  • Form fibrous plaque called ATHEROMA
  • Plaque partially blocks lumen of artery - restricts blood flow = increased blood pressure
  • Hardened arteries = ATHERSCLEROSIS
4 of 12

Thrombosis (Blood clotting)

  • Atheromas increase risk of thrombosis
  • Atheroma ruptures endothelium
  • Damages artery wall - leaves rough surface
  • Thrombosis  is triggered  - blood clot forms at site of rupture
  • Blood clot causes blockage of artery or dislodges and blocks another blood vessel
  • Blood flow to tissues is restricted - less oxygen reaches tissue = damage
  • Heart attack, stroke and deep vein thrombosis - CARDIOVASCULAR DISEASE
5 of 12

Cardiovascular Disease

Heart Attacks

  • Heart muscle supplied with blood by coronary arteries
  • Blood contains oxygen needed by heart muscle cells for respiration
  • Coronary artery becomes blocked by blood clot 
  • Area of heart muscle cut off from blood supply
  • Causes myocardial infarction (Heart Attack)


  • A rapid loss of brain function due to disruption in blood supply to brain
  • Caused by blood clot in artery, reduces amount of blood and oxygen to brain

Deep Vein Thrombosis (DVT)

  • Formation of blood clot in vein deep inside body - usually happens in leg veins
  • Caused by prolonged inactivity
6 of 12

Blood Cholesterol

  • High blood cholesterol increases risk of CVD
  • Cholesterol is a lipid
  • Needs to be attached to protein to be moved
  • Body forms lipoproteins

High Density Lipoproteins (HDLs)

  • Mainly protein
  • Transport cholesterol from body tissues to liver - recycled or excreted
  • FUNCTION: Reduce total blood cholesterol when level too high

Low Density Lipoproteins (HDLs)

  • Mainly lipid
  • Transport cholesterol from liver to blood - circulates until needed
  • FUNCTION: Increase total blood cholesterol when level too low

High total blood cholesterol level + high LDL level - linked to increased risk of CVD

7 of 12

Drugs for CVD - Antihypertensives

Antihypertensives - Reduce High Blood Pressure

  • Decrease risk of atheromas/blood clots forming
  • Diuretics - More urine so amount of blood decreased
  • Beta-Blockers - Reduces strength of heart beat
  • Vasodilators - Widens blood vessels


Blood pressure monitored at home


Palpitations / Fainting / Headaches / Drowsiness / Allergic Reaction / Depression

8 of 12

Drugs for CVD - Plant Statins

Plant Statins - Reduce Cholesterol in Blood

  • Contain Stanols / Sterols
  • Reduce blood cholesterol
  • Reduce amount absorbed by gut


Reduces risk of CVD


Reduces risk of absorption of vitamins

9 of 12

Drugs for CVD - Anticoagulants

Anticoagulants - Reduce Formation of Blood Clots

  • E.g. warfarin / heparin
  • Artery walls less likely to get damaged


Treat people with CVD / blood clots

Prevent new blood clots forming


Excessive bleeding if injured

Fainting / Allergic Reactions / Osteoporosis

10 of 12

Drugs for CVD - Platelet Inhibitory Drugs

Platelet Inhibitory Drugs - Reduce Formation of Blood Clots

  • Prevent platelets clumbing
  • Reduce chances of blood clotting = reduce chance of blocked blood vessels


Treat those with blood clots / CVD


Rashes / Nausea / Liver Function Problems / Constant Bleeding

11 of 12

Diet and Energy

  • Organisms take in and use up energy
  • Energy for growing, moving, reproducing

Energy budget - amount of energy taken in by organism and amount of energy used up

Energy Input - Energy output = Energy Budget

  • Higher intake than output = weight gain
  • Lower intake than output = weight loss
12 of 12


No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Health, illness and disease resources »