L4 - Mechanims Of Hypertension Flashcards
What are the stages of hypertension?
• Prehypertension: 120-139/80-89.
• Stage I: 140-159/90-99.
• Stage II: 160-179/100-109.
• Stage III: >180/>110.
What are the determinants of mean systemic arterial pressure (MAP)?
MAP = Cardiac Output (CO) x Total Peripheral Resistance (TPR).
What is the difference between primary and secondary hypertension?
• Primary (90-95% of cases): Idiopathic or essential, with no identifiable cause.
• Secondary (5% of cases): Due to renal, endocrine, or other specific disorders.
What are common causes of secondary hypertension?
• Renal disease.
• Renovascular disease.
• Mineralocorticoid excess.
• Sleep-breathing disorders.
What are the risk factors for hypertension and cardiovascular disease (CVD)?
• Family history, ethnicity, smoking, diabetes, obesity, hypercholesterolaemia, physical inactivity, stress, and age.
What are the target organs affected by hypertension?
• Cardiovascular system.
• Kidneys.
• Nervous system.
• Eyes.
What are the effects of hypertension on the heart?
• Left ventricular hypertrophy.
• Increased workload of the left ventricle.
• Risk of myocardial infarction, arrhythmias, and heart failure.
What are the effects of hypertension on the kidneys?
• Glomerular sclerosis.
• Impaired kidney function.
• End-stage kidney disease.
• Ischaemic kidney disease.
What are the effects of hypertension on the nervous system?
• Stroke.
• Cerebral atrophy.
• Dementia.
• Intracerebral and subarachnoid haemorrhage.
How does hypertension affect the eyes?
• Retinopathy.
• Retinal haemorrhages.
• Impaired vision.
• Retinal detachment.
What mechanisms contribute to hypertension?
• Loss of control in cardiac output (CO).
• Increased vascular resistance.
• Dysregulation in blood volume and vascular compliance.
What regulates arterial blood pressure?
• Baroreceptor reflex (neural control, immediate).
• Hormonal control (long term): Vasopressin, angiotensin II, aldosterone, atrial natriuretic peptide (ANP).
What is the role of the kidneys in long-term blood pressure control?
• Control blood volume via salt and water reabsorption.
• Renin-angiotensin-aldosterone system (RAAS) activation in response to reduced renal blood flow.
What is the significance of the renin-angiotensin-aldosterone system (RAAS) in hypertension?
• Causes vasoconstriction.
• Stimulates aldosterone synthesis, increasing sodium absorption and blood volume.
• Often inappropriately activated in renal or renovascular disease.
What are the key reinforcements about blood pressure control?
• Blood pressure is a silent killer driving CVD.
• Short- and long-term controls involve the autonomic nervous system (affecting CO and TPR) and kidneys (affecting TPR and fluid volume).
