General Flashcards
Describe the RAAS system initiated by the kidneys and its effects on blood pressure.
- Reduced Arterial pressure sensed
- Renin released by Juxtaglomerular cells
- Renin is an enzyme that produced angiotensin II
- Angiotensin II effects:
1) Vasoconstriction increasing peripheral resistance (BP = Cardiac output x peripheral resistance)
2) Stimulates aldosterone release from the cortex of adrenal glands which acts on distal tubule and collecting ducts promoting retaining sodium and as a result water
3) Stimulates ADH release from the pituitary
Name the three factors that stimulate release.
1- Sympathetic nerve activation due to baroreceptor feedback
2- Renal Artery hypotension
3- Decreased sodium in the distal tubule
Why do people with kidney problems have hypertension?
1- Activation of the RAAS system
2- Retention of salt and water with reduced excretory function
Name a vasodilator produced around the renal arteries.
prostaglandins (causes efferent vasodilation)
Describe the ‘clinical’ stages of hypertension.
1 = 140/90 with ABPM or HBPM 135/85 2= 160/100 with ABPM or HBPM 150/95 3= 180 systolic and over, or 110 diastolic and over
(If BP measured in the clinic is higher than one of the first values then you need to go on to measure ABPM or HBPM!)
Define hypertension.
A state of elevated arterial blood pressure
What is the blood pressure target for someone:
A) over 80
B) cardiac, renal disease or diabetes
A) 150/90
B) 130/80
Would the following increase or decrease blood pressure:
A) Age
B) Potassium
C) Sodium
A) Increase
B) Decrease
C) Increase
Name 4 risk factors of hypertension.
- Obesity
- Excessive alcohol
- Physical inactivity
- Sodium intake
(Family history)
Name types/categories of drugs that cause hypertension.
- Oral contraceptive pill
- Steriods
- NSAIDs
- Venlafaxine (Anti-depressant)
- illict drugs
Name causes of hypertension.
Primary Hypertension causes:
-Essential Hypertension
Secondary Hypertension Causes:
- Renal Disease (AKI)
- Heart Disease (only one is congenital –> Coarctation of the Aorta)
- Endocrine Disease
- Cushing’s (Excess in cortisol)
- Conne’s Disease (Aldosteronism or excess aldosterone dye to hyperplasia in adrenal glands)
- Phaeochromocytoma (increase in catecholamines)
State the 4 major consequences of hypertension (which can cause death).
1- Heart Failure
2- Myocardial Infarction
3- Renal Failure
4- Stroke
Describe how hypertension can cause heart failure.
Increase in blood pressure –> increase in total peripheral resistance –> increased afterload –> Left ventricular hypertrophy –> increased contractility –> increased oxygen/metabolic demand –> heart failure
What are the effects of the blood vessels? (3 effects)
1- Atherosclerosis (Any small arteries and arterioles but usually affects the heart)
2- Stroke (Narrowing and sclerosis of the cerebral arteries)
3- Retinopathy (damage to the vessels means they are hardened and no longer smooth and narrow –? leads to oedema and haemorrhages damaging the eyes)
Describe the effects of hypertension on the kidneys. (Just gain an understanding of this - this is actually nephrotic syndrome so remember the symptoms of that)
First: Autoregulation of BP by the kidneys tries to protect the kidneys
Second: You start to get albuminuria as there is damage to the basement membrane
Third: as there is continued high blood pressure the arteriolar walls thicken and narrow –> irreversible kidney function decline
Fourth: Urine excretion decreases (volume overload in the body + reduced clearance of creatinine, urea, and waste products)