1 / 63

Phase 1a Lauren Barker and Chiara Beck

Cardiovascular. Phase 1a Lauren Barker and Chiara Beck. The Peer Teaching Society is not liable for false or misleading information…. Aims. Anatomy Surface Anatomy Heart Borders Physiology Muscle Contraction Filaments Action Potential Cardiac Cycle Nodes Regulation of MAP

hayes-roberts
Télécharger la présentation

Phase 1a Lauren Barker and Chiara Beck

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Cardiovascular Phase 1a Lauren Barker and Chiara Beck The Peer Teaching Society is not liable for false or misleading information…

  2. Aims • Anatomy • Surface Anatomy • Heart Borders • Physiology • Muscle Contraction • Filaments • Action Potential • Cardiac Cycle • Nodes • Regulation of MAP • Effectors of CO and TPR • Baroreceptors and Chemoreceptors The Peer Teaching Society is not liable for false or misleading information…

  3. Aims • Anatomy • Surface Anatomy • Heart Borders • Physiology • Muscle Contraction • Filaments • Action Potential • Cardiac Cycle • Nodes • Regulation of MAP • Effectors of CO and TPR • Baroreceptors and Chemoreceptors The Peer Teaching Society is not liable for false or misleading information…

  4. Surface Anatomy The Peer Teaching Society is not liable for false or misleading information…

  5. Surface Anatomy Location: L 3rd IC space Auscultation: Right sternal edge, 2nd IC space Location: L 3rd CC Auscultation: L 2nd IC space Location: L 4th CC Auscultation: APEX L 5th IC space, mid-clavicular line Location: R 4th IC space Auscultation: R 5th IC space The Peer Teaching Society is not liable for false or misleading information…

  6. Borders of the Heart Superior: R 3rd CC  L 2nd CC Left: 2nd IC space, 2/3cm from midline  apex Anterior: sternocostal surface Right: 3rd 6th CC (2/3cm from midline) Inferior: Sternal 6th CC  apex AKA diaphragmatic surface The Peer Teaching Society is not liable for false or misleading information…

  7. Aims • Anatomy • Surface Anatomy • Heart Borders • Physiology • Muscle Contraction • Filaments • Action Potential • Cardiac Cycle • Nodes • Regulation of MAP • Effectors of CO and TPR • Baroreceptors and Chemoreceptors The Peer Teaching Society is not liable for false or misleading information…

  8. Physiology – Cardiac Contraction • Different to normal muscle contraction • Extracellular calcium ions • Sustains depolarisation of cardiac muscle cells for longer The Peer Teaching Society is not liable for false or misleading information…

  9. Physiology – Sarcoplasmic Reticulum The sarcoplasmic reticulum is the membrane network that surrounds the contractile proteins. Consists of sarcotubular network at the centre and the subsacrolemnal cisternae. The Peer Teaching Society is not liable for false or misleading information…

  10. Physiology – Contraction • Sliding of actin over myosin by ATP hydrolysis through the action of ATP-ase in the head of the myosin molecule. • When Ca2+ floods in, it binds to troponin, therefore moving tropomyosin off actin, exposing the binding sites. • The head of the myosin molecule forms crossbridges that interact with actin. The Peer Teaching Society is not liable for false or misleading information…

  11. Physiology – Contraction The Peer Teaching Society is not liable for false or misleading information…

  12. Physiology – Thick Filaments • Myosin: • 2 heavy chains – alpha and beta myosin heads • 4 light chains • Perpendicular at rest • Bends towards the sarcomere centre during contraction • Hydrolyses ATP, interacts with actin The Peer Teaching Society is not liable for false or misleading information…

  13. Physiology – Thin Filaments • Actin: • Globular protein • Double stranded helix • Both form F actin • Activates myosin ATP, interacts with myosin The Peer Teaching Society is not liable for false or misleading information…

  14. Physiology – Thin Filaments • Tropomyosin: • Elongated molecule made of 2 helical peptide chains • Regulates interaction!! The Peer Teaching Society is not liable for false or misleading information…

  15. Physiology – Thin Filaments • Troponin: • TnI: inhibits actin and myosin binding • TnC: Ca2+ binding sites • TnT: binds troponin to tropomyosin • TnC drives away TnI allowing interaction The Peer Teaching Society is not liable for false or misleading information…

  16. Physiology – Myosin ATP-ase • ATP binds to the myosin head inducing a small conformational shift in the actin-binding site which reduces its affinity for actin causing the myosin head to release the actin filament. • This causes the myosin head to ‘cock back’ into place. ATP is then hydrolysed leaving ADP and Pi bound to the myosin. • Weak interactions with actin cause the myosin to release the Pi which triggers the ‘power stroke’. • As myosin attaches, the ADP is released and it binds tightly to the actin. Rigor Mortis: lack of ATP, therefore the myosin cannot detach from the actin, meaning the muscles stay contracted. The Peer Teaching Society is not liable for false or misleading information…

  17. Physiology – Action Potential • 4 resting membrane potential (diastole) • 0 depolarisation • 1 transient outward partial repolarisation • 2 plateau • 3 repolarisation Hypocalcaemia? Reduced refractory period Tetany: spasms of the hands, feet, larynx, and cramps. The Peer Teaching Society is not liable for false or misleading information…

  18. Aims • Anatomy • Surface Anatomy • Heart Borders • Physiology • Muscle Contraction • Filaments • Action Potential • Cardiac Cycle • Nodes • Cycle • Regulation of MAP • Effectors of CO and TPR • Baroreceptors and Chemoreceptors The Peer Teaching Society is not liable for false or misleading information…

  19. Physiology – Conduction System • SA node: • Located near the entrance of the SVC • “Pacemaker” • AV node: • Located in the bottom of the right atrium • Only electrical connection between the atrium and ventricle • Slow propogation • Bundle of His • Purkinje fibres • Distributes the impulses throughout the ventricles The Peer Teaching Society is not liable for false or misleading information…

  20. Physiology – Cardiac Cycle • 3 main events: • LV contraction • LV relaxation • LV filling • Preload: load present before LV contraction has started • Afterload: load after the ventricle starts to contract • Sounds: • “Lub” – low pitched, closure of AV valves, marks onset of systole • “Dub” – louder, closure of semilunar valves, marks onset of diastole The Peer Teaching Society is not liable for false or misleading information…

  21. Aims • Anatomy • Surface Anatomy • Heart Borders • Physiology • Muscle Contraction • Filaments • Action Potential • Cardiac Cycle • Nodes • Regulation of MAP • Effectors of CO and TPR • Baroreceptors and Chemoreceptors The Peer Teaching Society is not liable for false or misleading information…

  22. Physiology – Regulation of MAP Average arterial blood pressure over a total cardiac cycle The sum of resistances to flow offered by all systemic blood vessels MAP = CO X TPR The volume of blood each ventricle pumps The Peer Teaching Society is not liable for false or misleading information…

  23. Physiology – Effectors of CO • Increase in sympathetic innervation to heart  INCREASE in BP • vasoconstriction • increased myocardial contractility • increase plasma adrenaline • Affects Heart Rate (HR) and Stroke Volume (SV) The Peer Teaching Society is not liable for false or misleading information…

  24. Physiology – Effectors of TPR • Vasodilators (decrease in TPR): • NO • CO2 • decrease in O2 • Inflammatory mediators • ANP (hormonal) • Vasoconstrictors (increase in TPR): • Sympathetic nerves • ADH • Angiotensin II • Adrenaline The Peer Teaching Society is not liable for false or misleading information…

  25. Physiology – Arterial Baroreceptors • Stretch-sensitive receptors found in wall of carotid sinus and aortic arch • Send neurons to medullary cardiovascular centre in brain • Key role in short-term regulation eg exercise • If becomes long term then adopt a new base line pressure • Main control in long-term BP regulation is blood volume. • FEEDBACK LOOP • Sensitivity is affected by sympathetic stimulation/hypertension Carotid sinus: glossopharyngeal nerve (CN 9) – more sensitive as going to brain Aortic arch: vagus nerve (CN 10) The Peer Teaching Society is not liable for false or misleading information…

  26. Physiology – Arterial Baroreceptors Stimulus Decreased sympathetic outflow to kidneys Increased renal blood flow and urine Increased sympathetic outflow to SA node Increased heart rate (HR) The Peer Teaching Society is not liable for false or misleading information…

  27. Physiology – Chemoreceptors • Small highly vascular bodies in the aortic arch and medial to carotid sinus. • Stimulated by a fall in O2 and pH/increase in CO2 • Involved in the control of respiration and reflex  vasoconstriction • Less important than baroreceptors in the control of circulation • CO2 and pH affect peripheral; O2 affects central • Increase in CO2  vasoconstriction, increase in PR and BP The Peer Teaching Society is not liable for false or misleading information…

  28. Pathology • Atherosclerosis • Heart failure • Thromboembolism • Shock • Myocardial infarction • Arrhythmias: • ECG The Peer Teaching Society is not liable for false or misleading information…

  29. Atherosclerosis The Peer Teaching Society is not liable for false or misleading information…

  30. Atherosclerosis • Endothelia injury – increased permeability. • LDL forms fatty streaks. • Monocytes attracted  macrophages. • Take up oxidised LDL to form foam cells. • Adhesion of platelets to endothelium. • Release cytokines and GF. • Migration of smooth muscle cells from media to intima  stabilize growing region. The Peer Teaching Society is not liable for false or misleading information…

  31. Complications • Plaque rupture: fibrous plaque ruptures exposing cholesterol etc. • Strong clotting reaction in blood. • Angina • Intermittent claudication • MI • Stroke The Peer Teaching Society is not liable for false or misleading information…

  32. Heart Failure • Definition: heart is unable to pump enough blood to satisfy needs of metabolizing tissues. • Breathlessness • Tiredness • Fatigue The Peer Teaching Society is not liable for false or misleading information…

  33. Heart Failure • CAUSES: • Myocardial dysfunction • Volume overload • Obstruction to outflow • Compromised ventricular filling • Altered rhythm The Peer Teaching Society is not liable for false or misleading information…

  34. Right Heart Failure • Symptoms: • Swollen ankles • Fatigue • Anorexia • Signs: • Raised jugular venous pressure • Hepatomegaly • Pitting oedema • Ascitis The Peer Teaching Society is not liable for false or misleading information…

  35. Left Heart Failure • Symptoms: • Fatigue • Breathlessness • Dyspnoea, orthopnoea, paroxysmal nocturnal dyspnoea. • Signs: • Cardiomegaly • Added heart sounds • Tachycardia • Crackles in lung bases The Peer Teaching Society is not liable for false or misleading information…

  36. Congestive Heart Failure • Mixture of both left and right. • Almost always right secondary to severe left heart failure. • Cor Pulmonale? The Peer Teaching Society is not liable for false or misleading information…

  37. Thromboembolism • Thrombus: blood clot forming inside vessel wall. • Thromboembolism: obstruction of a blood vessel by a dislodged blood clot. • Embolus: detached, travelling, intravascular mass: Examples: cholesterol, fat, air (gas) and tissue The Peer Teaching Society is not liable for false or misleading information…

  38. Thromboembolism Stasis Vessel Wall Blood Constituents The Peer Teaching Society is not liable for false or misleading information…

  39. Thromboembolism The Peer Teaching Society is not liable for false or misleading information…

  40. Shock • Definition: failure of cardiovascular system to adequately perfuse tissues. • Hypovolaemic shock • Distributive shock: • Septic • Anaphylactic • Cardiogenic shock The Peer Teaching Society is not liable for false or misleading information…

  41. Shock • Symptoms: • Faintness • Dizziness • Sweating • Pallor • Reduced level of consciousness The Peer Teaching Society is not liable for false or misleading information…

  42. Shock • Signs: • Pale, cold, clammy skin • Rapid, weak pulse • Tachycardia, decreased stroke volume • Rapid, shallow breathing • Impaired urine output • Confusion The Peer Teaching Society is not liable for false or misleading information…

  43. Hypovolaemic Shock • Fall in circulating blood volume: blood or fluid. • Loss of blood: • Trauma • Acute GI bleed • Haemorrhage • Operations • Loss of fluid: • Severe burns • Dehydration • Pancreatitis • Vomiting • Diarrhoea The Peer Teaching Society is not liable for false or misleading information…

  44. Hypovolaemic Shock • Class I-III: increasing in severity: • Pulse increases • Respiratory rate increases • Urine output decreases • Mental status declines The Peer Teaching Society is not liable for false or misleading information…

  45. Cardiogenic Shock • ‘Pump Failure’ • Interruption of cardiac function. • Heart unable to maintain circulation. • MI • Cardiac tamponade • Myocarditis • Pulmonary embolism • Valve failure – endocarditis • Fluid overload – poor left ventricular function • Obstructive shock? The Peer Teaching Society is not liable for false or misleading information…

  46. Septic Shock • Sepsis: systemic inflammatory response associated with an infection. • Septic shock: sepsis complicated by persistent inappropriate hypotension. • Unresponsive to fluid resuscitation. • Treatment with vasoconstrictors. The Peer Teaching Society is not liable for false or misleading information…

  47. Anaphylactic Shock • Hypersensitivity reaction. • Massive release of histamine. • Peripheral vasodilatation – hypotension. • Vascular permeability – loss of plasma. • Bronchial muscle contraction – dyspnoea. • Oral, laryngeal and pharyngeal oedema. The Peer Teaching Society is not liable for false or misleading information…

  48. Myocardial Infarction • Definition: necrosis of heart muscle due to impaired oxygen supply. • Usually occlusion of coronary artery by unstable atherosclerotic plaque. The Peer Teaching Society is not liable for false or misleading information…

  49. Myocardial Infarction • SYMPTOMS: • Chest pain • Radiates to neck and arm • Shortness of breath • Sense of anxiety • Profuse sweating • Nausea • Vomiting • Light-headed The Peer Teaching Society is not liable for false or misleading information…

  50. Myocardial Infarction • Consequences: • Arrhythmia • Heart failure • Pericarditis • Rupture: • Muscle • Walls • Valves The Peer Teaching Society is not liable for false or misleading information…

More Related