NR507 Advanced Pathophysiology 2024/2025.

NR507 Advanced Pathophysiology 2024/2025. How does blood flow through the heart? Deoxygenated venous blood → Sup. Vena Cava → Right Atrium →Tricuspid (AV) →Empties into R. Ventricle (& it contracts) → Blood ejected through Pulmonary Valve → Pulmonary Artery → Lungs to be Oxygenated → Pulmonary Veins → L. Atrium → Mitral (AV) → L. Ventricle (pumps with each contraction) → Aortic Valve → Aorta → Body What is systole? Contraction of the heart which pumps blood Diastole Relaxation of the heart What produces S1 and S2 sound? closing of the heart valves What produces S1? The mitral and tricuspid valves which close in systole What produces S2 sound? The closing of the aortic and pulmonic valves in diastole What is cardiac output? the volume of blood pumped out by each ventricle per minute What is stroke volume? amount of blood pumped out by each ventricle with contraction What determines cardiac output? stroke volume and heart rate What is preload? the degree of stretch on the heart before it contracts, related to ventricular filling, end diastolic pressure, amount of blood entering the ventricle during diastole What is afterload? resistance left ventricle must overcome to circulate blood What is contractility? Normal ability of muscle to contract at a given force for a given stretch. It is independent of preload/afterload Will sustained tachycardia result in increased or decreased stroke volume? Decreased What conditions can result in decreased contractility? Ischemia, acidosis, cardiomyopathy What can cause increase afterload? HTN, pulmonary disease, damage to the aortic valve What has the most immediate effect on afterload? HTN Why would hemorrhaging cause decreased afterload? Decreased volume of blood creates less resistance What does increased preload do to stroke volume? Increases stroke volume, over time the body will be unable to compensate however What can cause a decreased preload? Hemorrhage, dehydration...anything that causes reduced blood volume What side of the heart is affected by cor-pulmonale? Right (AKA Right sided HF) What is cor-pulmonale? is defined as right ventricular hypertrophy with eventual RV failure resulting from pulmonary HTN, secondary to pulmonary disease. Causes dilation (stretching) of the right ventricle causes a back up of blood flow, and hypertrophy of cardiac cells What conditions could cause cor pulmonale? COPD, PE, Pulmonary fibrosis, sleep apnea, myasthenia gravis, polio What are causes of heart failure? CAD, HTN, Cardiomyopathy, faulty heart valves Explain how systemic HTN can lead to heart failure? HTN causes increased LV preload which increases LA preload causing pulmonary edema What makes up the pulmonary anatomy? nose->pharynx->larynx->trachea->bronchi->bronchioles-->alveoli What is ventilation? The action of inhaling and exhaling What is perfusion? the ability of the lungs to perform gas exchange at the alveolar-capillary level moving blood into and out of the capillary cells What causes intrinsic asthma? Something internal, non-allergic factors (anxiety, chemicals, airborne irritants, exercise, GERD, obesity What causes extrinsic asthma? Triggered by chronic allergic reaction (mold, pollen, dust mites, pet dander) What are signs and symptoms of asthma? wheezing, shortness of breath, chest tightness, and coughing What are treatment options for asthma? Beta2-agonists and anticholinergics which block acetylcholine binding to promote bronchodilation What are signs and symptoms of chronic bronchitis? Productive cough, copious sputum, dyspnea, wheezing, rhonchi, cyanosis of skin and membranes, persists for at least three months consecutively for two successive years Where does the damage occur for chronic bronchitis? the airways (not alveoli) What causes chronic bronchitis? inflammatory cells activated in the bronchioles d/t irritants such as chronic smoke inhalation. The lamina propria which is a thin layer of connective tissue lining mucous membranes becomes inflamed and causes mucus secretion. What are long term effects of obstructive pulmonary disease? Secondary polycythemia, alveolar hyperinflation What is secondary polycythemia? A condition in which RBC numbers increase in response to hypoxic conditions: living at higher altitudes, smoking, chronic low O2 conditions like COPD (a lung disorder). This can lead to a blood clot What is alveolar hyperinflation? Due to decreased ability to exhale excess air becomes trapped in alveoli which causes an expanded thorax resulting in barrel chest and flat diaphragm What medications are used to treat chronic bronchitis?