L39 - Anatomy Of The Heart And Cardiovascular System Flashcards
What does the cross section of a ventricle look like after a myocardial infarction?
- dead muscle
- infarct resulting from lack of oxygen and nutrients
- caused by acute obstruction of coronary artery
What is the cause of ventricular fibrillation and then death?
- loss of blood supply/damage to heart
- pathological Q waves, T wave inversion
- loss of blood supply to body
What does the cardiovascular system do to transport over long distances?
Speeds up gas and solute
What is the function of the cardivascular system?
- deliver O2 and nutrients to cells
- remove CO2 and waste products from cells
- coms betweens organs
- temp regulation
- crucial hydrodynamic device in sexual reproduction
What does the CVS do to communicate between organs?
Transport of hormones and other extracellular mediators
What can the CV circulation be divided into?
- systemic circuit
- pulmonary circuit
- the heart as the central pump
What is the composition of blood?
- plasma 55%
- leucocytes and platelets
- erythrocytes/hematocrit - 45%
What is contained within the plasma in the blood?
- water
- ions
- proteins
- nutrients
- hormones
- metabolic wastes
- gases
What is the blood distribution like in the CVS?
- pulmonary circulation - 12%
- heart - 9%
- arteries - 11%
- arterioles and capillaries - 7%
- veins and venules - 61%
What is blood flow like at rest?
- brain - 13%
- heart - 4%
- skeletal muscle - 20%
- skin - 9%
- kidney - 20%
- abdominal organs - 24%
- other - 10%
What are the different layers in the blood vessels that regulate their function?
- lumen
- endothelial (tunica intima)
- smooth muscle cells (tunica media)
- connective tissue (tunica adventita)
What are the layers like in arteries?
- large lumen
- thick layer of smooth muscle (tunica media)
- thick later of connective tissue (tunica adventitia)
What does the thick layer of elastic smooth muscle act as in arteries?
Pressure reservoir
What is contraction and relaxation like in arteries to arterioles?
- systole - stretches - absorbes pressure
- diastole - passive recoil - releasing pressure
What are the layers like in arterioles?
- thin muscular wall
- small lumen
What does contraction of smooth muscle regulate in arterioles?
- diameter of the lumen
- determines blood flow to organs
- (major determinant of mean arterial pressure)
What is the layers like in capillaries, what does it allow/not allow?
- single layer of endothelial cells
- exchange of nutrient, oxygen and waste
- NOT proteins
What is exchange facilitated by in capillaries?
- slow movement of blood
- large SA within capillaries
- intercellular clefts and fused vesicles channels assist the exchange
What are the layer likes in venules? What does this allow?
- thin walls
- large diameter lumen
- have valves
- storage of large blood vol (60%)
What is the return of venous blood to the heart facilitated by?
- valves
- skeletal muscle pump
What is the overall structure of the heart?
- right side (small) - supplies the lung
- left side (large) - supplies the body
What are the different layers of the heart?
- myocardium
- epicardium
- pericardium
What are the different septums of the heart?
- apex - interventricular septum
- interatrial septum
What are the different valves in the heart? (Right to left side)
- right AV valve (tricuspid)
- pulmonary semilunar valve
- left AV valve (bicuspid, mitral)
- aortic semilunar valve
What are the tendons that hold the valves? (Far to close to septum)
- chordae tendinae
- papillary muscle
What is the route of blood flow in the heart?
- R atrium, R ventricle, pulmonary valve, to lungs
- L atrium, L AV valve, L ventricle, aortic valve to rest of the body
What is blood supply like in the heart?
- network of blood vessels with oxygenated blood by coronary arteries
- coronary arteries branch off the aorta (LV)
- most deoxygenated blood drains into RA by coronary sinus
What is coronary arterial disease?
- insufficient blood flow (ischemia) related to chest pains (angina) - radiates down L Arm
- severe blockage can lead to death or myocardial infarction
What are causes of CAD?
- atherosclerosis (thickening)
- blood clot (coronary thrombosis)
- drugs
- surgery
How do you treat CAD?
- dye shows blockage of right coronary artery
- guide wire used to insert balloon that is inflated to allow insertion of wire stent
- repaired vessel
What are the layers around the brain?
- skin
- periosteum
- dura metter
- arachnoid
- (CSF and blood vessels)
- pia matter
What is the function of the CSF?
- cushions brain against damage
- produced in specialised epithelial cell (choroid plexus)
What is circulation around the brain and spinal cord driven by?
- changes in circulation, respiratory and posture
- passses into vein via valves at the top of the skull (arachnoid villus)
What are blood vessels and the blood brain barrier like?
- vessels dive into brain
- capillaries contain tight junction, less permeable (difficult to get drugs and proteins apart from lipophilic molecules like anaesthethics, alcohol)
- no stored glycogen, requires constant supply of glucose and O2
- loss of blood supply and death of neurons - stroke
