Hypertension

Question 1

What are the systolic and distolic levels for various blood pressure categories?

Answer 1

Normal - > 120/80
Elevated - 120-129/80
Stage 1 hypertension - 130-139/80-89
Stage 2 hypertension - 140 ot higher/ 90 or hoigher
Hypertensive crisis - >180/ >120

Question 2

What regulates blood pressure?

Answer 2

Peripheral mechanisms
- carotid baroreceptors (pressure from blood flow)
- chemoreceptors
- aortic baroreceptors
- cardiac afferents
- renal afferents

Central mechanisms
- efferents that produce neurotransmitters
- renal efferents
- sympathetic efferents
- vagal efferents

Question 3

How can lifestyle factors have an effect on bp?
Changes in systolic blood pressure.

Answer 3

Weight reduction - 5-10mmHg/ 10kg
Diet - 8-15mmHg
Physical activity
Oral health - 5mmHg

Accumulation of factors can add up the systolic bp changes and cause a large decrease in systolic blood pressure.
Especially for those who are stage 1 or 2 who have hypertension due to being a higher weight, or having a bad diet, physically inactive. Lifestyle changes can make huge differences.

Question 4

What are some medications prescribed for hypertension?

Answer 4

Diuretics
Vasodilators
- Calcium channel blockers
- Parenteral vasodilators
Angiotensin antagonists
- ACE inhibitors
- Receptor blockers
Renin inhibitor
Sympathoplegics
- Alpha or beta-blockers
- Nerve terminals
- CNS sympathetic outflow
- Ganglia

Question 5

What is resistant hypertension?

Answer 5

Over 140mmHg and taking 3+ drugs without any blood pressure improvement
Large risk of CVD
Taking medications chronically (in long term) can lead to the ineffectiveness of drugs and can then even lead to resistance.

Question 6

How is Nitic Oxide produced?
Non-enzymatic pathway.

Answer 6

Nitrate in diet, eaten
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Nitrate is concentrated in the blood by the salivary glands and enters the oral cavity
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Nitrate is reduced to nitrite by commensal bacteria. Symbiotic relationship
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Nitrate is further reduced to nitric oxide i the acidic environment of the stomach
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Nitric oxide causes vasodilation of blood vessels

Question 7

How does nitric oxide effect blood vessels?
Mechanism

Answer 7

A mechanical stimulus such as increased blood flow triggers the increase of phosphorylation of endothelial nitric oxide synthase in endothelial cells causing them to activate
eNOS causes a reduction in the amino acid L-arginine and creates NO
Nitric oxide diffuses to the middle layer where smooth muscle cells are located.
NO activates a cascade response of proteins which in turn causes relaxation of the medium layer.
This relaxation facilitates artery expansion and overall vasodialtion.

Acetycholine, cytokines can also cause this.

Question 8

How do endothelial 1 effect blood vessels?
Mechanism

Answer 8

Mechanical stimulus, cytokines, growth factors or hypoxia, activate pre-endothelial 1 which in turn activate endothelial 1.
This downregulates NO and diffuses to the middle layer where is down regulates cGMP
This causes the blood vessel walls to contrsict and cause vasoconstriction