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
How to control primary/essential hypertension?
- Diet
- Losing weight
- Smoking cessation
- Reducing alcohol
- Managing stress
What is secondary hypertension?
- 10% of cases of hypertension
- Cause is identifiable → renal failure/obstruction of renal arteries, pregnancy, hyperthyroidism
- Resolving cause returns blood pressure to normal
What are effects of hypertension on the body?
Can cause:
- Stroke
- Blood vessel damage (arteriosclerosis)
- Heart attack or heart failure
- Kidney failure
How doe hypertension promote atherosclerosis?
- Damage to the endothelium of the blood vessels
- Thickening of the arterial wall and decreased lumen
- A decreased lumen will increase peripheral resistance
- An increased peripheral resistance will increase fat deposits decreasing the lumen further
What does uncontrolled blood pressure cause?
Heart failure since heart and blood vessels are overworked
How to prevent and control hypertension?
- Exercise
- Diet
- Medications
