BODY SYSTEMS
CARDIOLOGY
,Medic_Summaries (Body Systems)
Cardiology Strand
Basic function of the cardiovascular system (CVS):
- Maintain constant internal environment (homeostasis)
- Deliver products for respiration and cellular activity (O2 and nutrients)
- Remove by-products of cellular activity (CO2 and waste)
- Provide an opportunity for cellular products (e.g. hormones) to spread around the body
Blood vessels:
Components of CVS:
- Pump: specialised muscle (myocardium); actually two pumps (atria and ventricles)
- Closed system of tubes: carry blood to/from capillary beds
- Actually two circulations: systemic and pulmonary
- Two functional parts:
- Conducting system: vasculature (arteries and veins)
- Arteries take blood away from the heart (oxygenated, except pulmonary a.)
- Veins bring blood back to the heart (deoxygenated, except pulmonary v.)
- Exchange system: capillary beds
- Link smallest arterioles to smallest venules
- Forms a continuous exchange system between blood and extracellular fluid
Right atrium:
Right ventricle:
Left ventricle/atrium:
2 Adapted from Lectures at the University of Leeds Medical School
, Medic_Summaries (Body Systems)
Aorta and great vessels:
- Ascending aorta
- Arch of aorta:
- Carotid arteries (supplies head)
- Subclavian arteries (supplies ULs)
- Descending aorta:
- Supplies trunk and LLs
The pump needs power: coronary circulation
- Two coronary arteries (left and right)
- Only branches of the ascending aorta
- Right coronary artery supplies the main conducting centres of heart (SAN and AVN)
Coronary arteries:
- Little overlap between territories of distribution
- Sudden blockage may lead to ischaemia (reduced/inadequate blood supply)
- This may lead to myocardial infarction (MI):
- Sudden blockage leads to tissue being served of oxygen (hypoxia)
- Localised hypoxia is called ischaemia
- Ischaemia of myocardium leads to infarction (local tissue death)
Descending aorta:
- A: ventral, unpaired arteries to GIT (e.g. coeliac trunk)
- B: paired, arteries to paired internal organs (e.g. kidneys)
- C: paired, segmental arteries to body wall (e.g. intercostal arteries)
Aorta passes through DIAPHRAGM at T12
Aorta BIFURCATES at L4
Coarctation of aorta leads to collateral circulation:
- Abnormal narrowing (stenosis) of the aorta decreases blood flow to the body
- Occurs around where the arch and descending aorta meet
- This means that the head and ULs are exempt from the decreased blood flow
- Collateral circulation develops via intercostal and internal thoracic arteries
Limb vessels:
- Arteries:
- Two pairs of arteries supply the limbs:
- UL supplied by subclavian artery
- LL supplied by external iliac artery
- Artery names change depending on location (e.g. subclavian, axillary, brachial)
- A single vessel supplies the proximal part of a limb (UL and LL)
- This divides into two major branches at the elbow/knee
- Bifurcation occurs in flexor compartment of limb (protected)
- Veins:
- Veins generally mirror arteries:
- UL drains into subclavian vein
- LL drains into external iliac vein
Deep veins:
- Usually duplicated or triplicated
- Surround corresponding artery
- Arterial contraction and valves aid venous return (AV pump)
- Help to maintain core body temperature (countercurrent heat exchanger)
3 Adapted from Lectures at the University of Leeds Medical School
CARDIOLOGY
,Medic_Summaries (Body Systems)
Cardiology Strand
Basic function of the cardiovascular system (CVS):
- Maintain constant internal environment (homeostasis)
- Deliver products for respiration and cellular activity (O2 and nutrients)
- Remove by-products of cellular activity (CO2 and waste)
- Provide an opportunity for cellular products (e.g. hormones) to spread around the body
Blood vessels:
Components of CVS:
- Pump: specialised muscle (myocardium); actually two pumps (atria and ventricles)
- Closed system of tubes: carry blood to/from capillary beds
- Actually two circulations: systemic and pulmonary
- Two functional parts:
- Conducting system: vasculature (arteries and veins)
- Arteries take blood away from the heart (oxygenated, except pulmonary a.)
- Veins bring blood back to the heart (deoxygenated, except pulmonary v.)
- Exchange system: capillary beds
- Link smallest arterioles to smallest venules
- Forms a continuous exchange system between blood and extracellular fluid
Right atrium:
Right ventricle:
Left ventricle/atrium:
2 Adapted from Lectures at the University of Leeds Medical School
, Medic_Summaries (Body Systems)
Aorta and great vessels:
- Ascending aorta
- Arch of aorta:
- Carotid arteries (supplies head)
- Subclavian arteries (supplies ULs)
- Descending aorta:
- Supplies trunk and LLs
The pump needs power: coronary circulation
- Two coronary arteries (left and right)
- Only branches of the ascending aorta
- Right coronary artery supplies the main conducting centres of heart (SAN and AVN)
Coronary arteries:
- Little overlap between territories of distribution
- Sudden blockage may lead to ischaemia (reduced/inadequate blood supply)
- This may lead to myocardial infarction (MI):
- Sudden blockage leads to tissue being served of oxygen (hypoxia)
- Localised hypoxia is called ischaemia
- Ischaemia of myocardium leads to infarction (local tissue death)
Descending aorta:
- A: ventral, unpaired arteries to GIT (e.g. coeliac trunk)
- B: paired, arteries to paired internal organs (e.g. kidneys)
- C: paired, segmental arteries to body wall (e.g. intercostal arteries)
Aorta passes through DIAPHRAGM at T12
Aorta BIFURCATES at L4
Coarctation of aorta leads to collateral circulation:
- Abnormal narrowing (stenosis) of the aorta decreases blood flow to the body
- Occurs around where the arch and descending aorta meet
- This means that the head and ULs are exempt from the decreased blood flow
- Collateral circulation develops via intercostal and internal thoracic arteries
Limb vessels:
- Arteries:
- Two pairs of arteries supply the limbs:
- UL supplied by subclavian artery
- LL supplied by external iliac artery
- Artery names change depending on location (e.g. subclavian, axillary, brachial)
- A single vessel supplies the proximal part of a limb (UL and LL)
- This divides into two major branches at the elbow/knee
- Bifurcation occurs in flexor compartment of limb (protected)
- Veins:
- Veins generally mirror arteries:
- UL drains into subclavian vein
- LL drains into external iliac vein
Deep veins:
- Usually duplicated or triplicated
- Surround corresponding artery
- Arterial contraction and valves aid venous return (AV pump)
- Help to maintain core body temperature (countercurrent heat exchanger)
3 Adapted from Lectures at the University of Leeds Medical School
