Fichas
The Heart
Fichas del conjunto (87)
- 1What is Cyanosis?- Blue Fingers
- 2What is the mediastinum?- Everything except the lungs and the pleura (where the heart sits)
- 3At what point does the aorta come out of the heart?T4/ T5 = sternal angle
- 4Describe the fibrous pericardium- Fused superiorly to great vessels (adventitia of vessels) and blended inferiorly with diaphragm
- 5What is a pericardial effusionFluid in the pericardial cavity that puts pressure on the heart
- 6What are pericardial sinusesReflections of the serous pericardium off the heart
1) Transverse pericardial sinus
2) Oblique pericardial sinus - 7What is the remnant of the ductus arteriosusLigamentum arteriosum between aorta and pulmonary trunk
- 8True or false, veins are anterior to arteries?True
- 9Name the branches of aorta1) Brachiosephalic (splits into R. common carotin and R. subclavian)
2) L.common carotid
3) L. subclavian - 10Name branches of superior vena cavaL and R brachiosephalic veins
Subclavian and Carotid drain into them - 11The fossa ovalis is the remnant of what structure?Foramen oval
- 12Name the parts of the tricuspid valve?1) Anterior cusp
2) Posterior Cusp
3) Septal cusp - 13How are valves held tight?Papillary muscles holding chordae tendinae (heart strings)
- 14What is the moderator band and where is it found?Contains the right av bundle and is found in the right ventricle
- 15What is the name of the muscles in the ventricles and what is their function?- Trabecule carnae
- They prevent suction - 16What is the name of muscles on the atrium?- Musculi Pectinati (comb like)
- Originate from the cristae terminalis - 17Where are the coronary arteries and when are they filled?- Aortic sinus is superior to the aortic valve and fills with back flow of blood during diastole
- 18True or false, the right anterior descending artery is intraventricular.False it is the left anterior descending artery that is intraventricular
- 19What does it mean if your heart is codominant?Posterior descending artery is supplied by both left and right coronary arteries
- 20What are the 3 types of cardiac cell?1) Contractile
2) Myoendocrine (release factors)
3) Nodal (specialised in SA and AV node - 21What is stroke volume?Vol of blood in one pump
- 22What is cardiac output?Blood per beat
- 23How is heart steady state defined?Venus return = Cardiac output
- 24What are the resistance vessels?Small arteries and arterioles, have the biggest drop in pressure
- 25What are the capacitance vessels?Venules and veins, also act as blood storage
- 26Blood flow (Q) is equal toDelta pressure/ Resistance
- 27How is RMP generated and maintained?Generated through outward movement of K+ via potassium leak channels
Maintained via Na+/ K+ pump - 28How does heart contractile muscle differ to other smooth muscle?Troponin is the Ca2+ sensor not calmodulin. Binds to myosin when not contracting
- 29What is a syncitium?- Cardiac muscle cells working together
- 30How do cardiac muscle cells manage to work as a syncitium?- Via intercalated discs (gap junctions and desmosomes)
- Via conducting fibres - 31What is the annulus fibrosis- Fibrous ring that electrically insulates made from collagen
- 32How does the heart differentiate from mesoderm?1 - Embryonic mesoderm
2 - Lateral plate mesoderm
3 - splanchic mesoderm
4 - heart and mandibular - 33What 2 progenitor cell types exist in the cardiac crescent?1) Primary heart field mesoderm (PHF)
2) Secondary heart field mesoderm (SHF) - 34What are ectodermal neural crest cells and what is their role?- They are ectodermal cells that originally were part of the neural crest and migrate to the heart to cause differentiation
- 35True or false, defects in neural crest cells can cause facial and heart defects?True because neural crest cells migrate and help the face, heart and PNS to develop
- 36How does the pleural cavity form around the heart?- Mesoderm surrounds endocardium
- Epicardium surrounds myocardial mesoderm
- Pleural cavity forms around heart tube - 37Describe the establishment of the heart tube- Occurs at 3 weeks
-PHF cells form heart tube (forms chambers)
- SHF migrate to heart to form outflow and inflow tracts
- Aortic arch arteries are remodelled by CNCCs and connect to outflow tract to form great vessels - 38True or false, the inflow tract is made of the SVC, IVC and pulmonary vessels?False, The inflow tract is only made of the SVC and IVC, the pulmonary vessels develop independently
- This is called the sinsous venousus - 39Describe the outflow tract?1) First the aortic sac develops
2) Two outflow vessels
3) Above the aortic sac is the aortic arches
4) Below the aortic sac are the truncus arteriosus, conus cordis and bulbus cordis in descending order - 40What is the order of formation of the septas?At 21 days = 3 weeks
1) AV septum formation
2) Aortic sepation septum formation
3) Ventricular septum formation
4) Aorticopulmonary septum formation in the outflow tract - 41What forms the septa?Sub-endocardial cushions that fuse
- 42Describe formation of the atrial septa- Initially blood cant pass through atria because of the primary septum
- Hole forms in the primary septum (foramen ovale)
- Secondary septum also formed at at birth they join to form the fossa ovalis - 43What is an atrial septal defect?Hole in the septum of atria, failure of foramen ovale to close
- 44Describe ventricular sepation- This time not via sub endocrinal cushions but with muscular inter-ventricular septum
- 45Describe aortico-pulmonary septationSeparation of the outflow tract into pulmonary and aorta
extention of ventricular septum via NEURAL CREST CELLS - 46What causes an AP sepation defect- When neural crest cells miss muscular ventricular septum so there is a gap between that and the aortico-pulmonary septum
- Results in pulmonary stenosis (narrowed pulmonary artery) - 47What is the ductus arteriosus?between pulmonary artery and descending aorta that allows blood to pass foetal lungs
- 48What is tetrology of fallot and what are the 4 features?- It is a congenital heart disease
1) pulmonary stenosis
2) Overiding aorta
3) Ventricular septal defect
4) Right ventricular hypertophy - 49How many beats per min does the SA node produce?70 beats/min
- 50What kind of ion channels are involved in pacemaker action potential?- Slow opening Na+ funny channels to reach threshold
- normal Ca2+ to top
- K+ to repolarise - 51True or false, the intrinsic rate of action potentials by the SA node is lower than the actual resting heart rate?False the intrinsic rate is higher (100 beats per min) but body releases Ach to improve dynamic range
- 52Describe the ion channels involved in action potentials at muscle cells?- Voltage gated gated Na+ channels
- Then l-type calcium channels for sustained contraction
- Then K+ Channels for repolarisation - 53What specialised ion channels cause contraction and why?L type calcium channels cause influx of trigger calcium which causes calcium induced calcium release
- 54What is the isoelectric point?when all the cells are in the same state, Omv on ECG
- 55What is the P-R intervalFrom beginning to end of atrial systole. Just before QRS complex
- 56What is the QT intervalContraction and repolarisation of ventricles
- 57ST intervalFrom end of S to beginning of T, Ventricular contraction
- 58Describe and explain the 2 types of arrhythmia1) Impulse propagation, problems in conducting cells (3types of heart block)
2) Impulse initiation e.g. ventricular and atrial fibrillation (more dangerous e.g. due to blood clot) - 59How do you distinguish between heart block and atrial fibrilation on an ECG?Look at the S/T wave
Heart block = inverted S/t
Atrial fibrillation = little or no s/t - 60What are the 3 types of heart block and how are they distinguished?1) 1st degree = Delay in AV node = prolonged PR interval (s wave)
2) 2nd degree
- MobitzType 1 = delay in AV node getting bigger with each beat = increasingly prolonged PR interval
- Type 2 = similar to type 1, but more irregular and skipped beats (no gradual increase)
3) 3rd degree = complete heart block, no action potentials reach. P waves not coordinated with QRS - 61What interval varies significantly with heart rate?TP interval
- 62What is isovolumetric contractionVentricular contraction without change in volume, occurs before ventricular rejection
- 63What is the ejection fraction?Stroke volume/ EDV
- 64What is the dichrotic notch?Where aortic valve closes
- 65How to find MAP= DP - 1/3(SP - DP)
- 662 types of valve disease?- Stenosis
- Incomopetance - 67Describe heterometric control of the heart?- Also known as intrinsic or autoregulation of the heart
- Frank-sterlings law = Force of contraction proportional to fibre length initially in diastole
- Therefore = increase in stroke volume - 68Why does stretching of muscle fibres result in increased force of contraction?- More overlap in actin and myosin, more interaction between the two
- Also increased sensitivity to ca2+ - 69Why does heart rate increase when lying down?Gravity causes more blood to enter right atrium = increase in EDV = increase in heart rate
- 70Describe extrinsic control of heart?- Also called homeometric control
- Autonomic nervous system control of heart
- Increase in SV without change in fibre legnth
- CAMP acts as an intracellular messenger, trigger calcium channels open for longer and also interacts with actin-myosin interactions - 71What kind of drug is phentolamine?A1 and A2 antagonist
- 72What kind of drug is atropineNicotinic antagonist
- 73What effect would calcium chloride have on heart rate?- Increased contractility but no effect on heart rate
- 74What effect does hitting the chest wall have in ventricular fibrillation?Causes physical depolarization of membranes stopping ectopic stimuli
- 75What is the most common cause of heart failure?- Ischaemic heart disease. Imbalance between supply and demand of the heart for oxygenated blood
- 76What determines which of the 4 ischaemic syndromes result?- Rate and severity of arterial narrowing and myocardial response
- 77What is angina pectoris- Strangling in chest, jaw and back
- Transient ischaemia that doesnt usually cause necrosis
- Activation of chemoreceptors by metabolites cause pain
- Treated by improving blood flow e.g. glyceryl trinitrate that generates NO and reducing work of heart e.g. giving B-blockers - 78How does NO act- Relaxes smooth muscle via CAMP pathways, locally generated or from drugs like glycerol trinitate
- 79Describe myocardial infaction?- Ischaemia causing necrosis of the heart (irreversible)
- Commonly transmural = across wall chamber
- E.g. ST elevation, T wave inversion and abnormal Q wave - 80Describe chronic heart failure?- Developed over many years as the result of progressive myocardial damage
- Leads to odema
- Increase in venus and capillary pressures - 81Difference in left and right sided heart failure?Left = pulmonary odema
Right = peripheral odema - 82How does the body try and correct chronic heart failure?- Frank sterling helps at first but heart muscles become over stretched and decreases heart performance
- Kidneys = hypervolaemia to increase blood vol and cardiac output - 83How is chronic heart failure treated?- Vasodilators
- B1 agonists to increase contractility
- B1 antagonists to some patients to reduce work of heart
- Control fluid retention by giving diuretics or ACE inhibitors - 84What are the pros and cons of X-raysGo through less dense material, cheap, portable, good for bone images
Cannot distinguish between tissue types - 85Pros and cons of CT scans- More detail than xray, 3D slices, good for bony detail, fast
- High radiation dose because of - 86Pros and cons of MRI- Can distinguish between tissue types, no radiation (magnetic), 3D, good for soft tissue detail e.g. brain
- Safety (huge magnet) - 87Pros and cons of ultrasound- Completely safe
- Cheap and portable
- Limited by bone, fat and gas
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- Fichas sobre The Heart, creado por Wannie Chisala el 06/01/2017.
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- Wannie Chisala
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