Hypertension Flashcards
Arteries have a thicker ______ than veins.
Tunica media
What is the frank starling law of the heart?
The more stretched out the muscle fibres are in the heart the stronger the contraction resulting in greater stroke volume
What are the vasoconstrictors in the body?
Ang II, catecholamines, thromboxane, endothelin, vasopressin
What are the vasodilators in the body?
Nitric oxide, prostaglandins, kinins
Stimulation of alpha-adrenergic receptors causes smooth muscle ______
constriction
Stimulation of beta-adrenergic receptors causes smooth muscle _______
relaxation
High pressure sensing baroreceptors can be found in the _____
carotid sinuses and aortic arch
Low pressure sensing baroreceptors can be found int the
heart and vena cavae
How does the heart regulate BP?
-makes natriuretic peptides which affects the kidneys
-changes stroke volume thereby affecting CO
(CO = HR x SV)
What local factors are secreted by the endothelium?
Nitric oxide, endothelin, Ang II
Venous compliance
ability of capacitance vessels to distend and increase diameter with increasing pressure
When BP is high, capacitance vessels respond by…
dilation/distention causing reduced venous pressure and reduced preload; when preload is reduced end diastolic volume is reduced
What are the effects of natriuretic peptides?
- increase glomerular filtration
- prevent salt uptake and inhibits renin release (decrease pressure)
- reduce blood volume
Explain the tubuloglomerular feedback system
Low blood volume/low GFR detected by renal tubules; feedback to glomerulus to increase sodium and water reabsorption; blood volume increases
In which organ is angiotensin I converted to angiotensin II?
Lungs
Define natriuresis
sodium excretion in the urine (increase urine)
What are the functions of ANP/atrial natriuretic peptides?
- inhibit renin release
- increase sodium excretion
- acts as vasodilator in the kidney to increase GFR
What is the likelihood of HTN in persons > 60 years old?
65%
What are the top 3 ethnicities with the highest rates of HTN?
African-American 33%, Caucasian 29%, Hispanic 21%
What is the threshold BP for hypertensive crisis?
180/110
Gestational HTN is diagnosed after how many weeks of pregnancy?
20 weeks
What the initial signs of pre-eclampsia?
High blood pressure and large amount of proteins in the urine
What BP reading is considered diagnostic of pregnancy HTN?
2 readings of 140/90, +6 hours apart
What are some drugs that can cause increase in blood pressure?
Amphetamines, NSAIDs, cocaine, decongestants, steroids
