Hypertension Flashcards
What is hypertension?
- Chronically elevated BP above 140/90
- Or 135/85 when high risk
What is blood pressure?
Pressure exerted by the blood on the walls of blood vessels.
What determines blood pressure?
- Cardiac output (heart rate x stroke volume)
- Peripheral resistance (vessel diameter and length)
- Blood volume
- Blood viscosity
What is pulse pressure?
The difference between the systolic and diastolic pressure
What is mean arterial pressure?
- Pressure that propels the blood through the tissues
- Diastolic Pressure + ⅓ pulse pressure
What increases mean arterial pressure?
An increase:
- Cardiac output
- Peripheral resistance
What increased stroke volume and heart rate?
- Exercise
- Fright
- Anxiety
What regulates blood pressure?
- Renin angiotensin aldosterone system
- Natriuretic Peptide (ANP & BNP) Release
- Other mechanisms including antidiuretic hormone (ADH) and regulation of blood volume
What triggers the renin angiotensin aldosterone?
Low blood pressure
How does the renin angiotensin aldosterone system work?
- Renin (from kidneys) converts angiotensin 1 into angiotensin 2 causing vasoconstriction
- Angiotensin 2 release ADH release + aldosterone release
- This increases water and sodium absorption in the kidneys
- Increases blood volume
- Increases BP
What triggers natriuretic peptide (NP) release?
High blood pressure
How does natriuretic peptide (NP) release work?
Decreases renin release, inhibiting renin angiotensin aldosterone system
What is are cardio-renal interactions?
- Regulation of the glomerular filtration rate
- Designed to maintain BP and homeostasis
What is primary/essential hypertension?
- 90% of cases of hypertension
- No underlying cause identified
- Cannot be cured but can be controlled
What are likely causes of primary/essential hypertension?
Likely to be a mix of hereditary and environmental (life style) factors → Heredity (runs in families), diet, age, stress
