Coronary Circulation Flashcards
What does left side contain?
Oxygenated blood
What does diffusion coefficient allow?
Oxygen to diffuse across max of 1mm tissue
How does the heart have its own circulation?
Coronary arteries , squeeze shut during heart contraction and fill during relaxation
What 2 coronary arteries branch from aorta?
Left coronary artery passes anterior to LA and divides into Anterior inerventricular (LAD) and Circumflex branches
What does LAD do?
Extend along anterior inerventricular sulcus and supplies blood to both ventricules
What does circumflex do?
runs along coronary sulcus and provides LV and RA with blood
What does Right coronary artery do?
Inferior to RA with small atrial branches supply RA with blood
branches to posterior intraventricular and right marginal branches
What does posterior interventricular branch do?
Follow post.Interve.Sulc and supplies both ventricle
What does right marginal branches do?
Follows coronary sulcus and RV with blood
What does coronary veins do?
Deoxygenated blood drains from coronary capillaries to veins transfers blood to thin wall coronary sinus drains RA
What does coronary sinus do?
Supply deoxygenated blood via great cardiac (anterior) and Middle cardiac vein (posterior)
When does ischaemia occur?
Partial obstruction of coronary artery cause myocardial ischemia causes hypoxia decreased ATP - modifies actin/myosin, inhibits na/k pump and inihibits ATP K channe;s - induce angina pectoralis
What does Angina Pectoralis occur?
Severe pair in neck chin or left arm
tight sensation in chest
additional exertions at rest
lead to myocardial infarction
What is myocardial infarction?
Myocardial cells induce by blockage of blood supply to region of heart, forms scar tissue
What happens to Heart muscle in MI?
loose contractile strength
Scar tissue isolate AV node
Ventricular fibrillation - asynchronous contracts of ventricles
Defibrillation depolarises cell to resynchronize
What is CAD? coronary artery disease
Medical problem accumulation of atherosclerotic plaques in coronary arteries low blood flow leads to- no sigh chest pain heart attack
What are lipoproteins?
Lipids transported in blood with proteins, inner tryglycerides and hydrophobic shells of phospholipisds cholesterol and apoproteins
What is Lipoprotein classification?
HDL-C particles
LDL-C particles
VLDL low desne lipprotein
Chylomicrons
How are lipoproteins transported?
different pathways by apoprotein in phospholipid shell
What is apoprotein function?
ligands for receptors enabling direct transport B100 in LDLC particles for steroid synthesis
What happens to cholesterol and triglycerides?
absorbed by ileum and transported via chylomicrons in lymph to blood
What happens in muscle and adipose tissue?
Triglycerides are hydrolysed and tissues taken up by fatty acids and glycerol
What are chylomicrons?
Still contain cholesterol esters pass to liver bind to receptors, endocytosed
Wheres cholesterol stored?
In liver, oxidised to bile acids secreted in bile and endogenous pathway
What is process for formation of atherosclerotic plaque?
Initial early inflammatory cell filtrate intermediate advance
What are statins?
inhibit HMG-CoA and mevalonate pathway for hypercholesterolemia
What are Fibrates?
Increase hepatic LDLC uptake in hypercholesterolemia
What are Bile acid binding resins?
Reduce cholesterol absorption from intestines LDL recepttors for clearnace from blood cause diarrohea
