hypertension Flashcards
what are the values to show hypertension
systolic blood pressure above 140mmHg
diastolic blood pressure over 90 mmHG
where are the baroreceptors
aortic arch and carotid sinus
what happens to baroreceptors when there is an increase in the blood pressure
- increased stretch in blood vessels
- activated sodium channels
- depolarisation
- increased action potentials to adrenal medulla
what is found in the vasomotor
C1 and A2 nuclei
what does the C1 nuclei of the vasomotor centre do
vasoconstriction
what does the A1 nuclei of the vasomotor centre do
vasodilation
what does an increase in blood pressure do to the medulla
stimulates the C1 nucleus in the vasomotor ventre
inhibits the cardiac acceletory
stimulates the cardiac inhibitory
what does inhibition of the cardiac acceletory do
- prevent innervation to tunica media to cause vasodilation
- adrenal medullary fibres are inhibited to decrease adrenaline and noradrenaline release
- more vasoconstriction overall
what does the cardiac inhibitory centre do when there is high blood pressure
- vagus releases acetylcholine to the nodes
- acts on type two muscarinic receptors
- g inhibitory protein activated
- calcium entry decreases
- potassium leaves the cell
- interior is hyperpolarised to mean it takes more time for action potentials to occur
- decreases cardiac output.
what do the atria do when there is high blood pressure
they stretch and stimulate endocrine cells that secrete atrial natriuretic peptide
what does atrial natriuretic peptide do
inhibit the actions of angiotensin two and aldosterone
when does polyuria occur
when we have high blood pressure as the aldosterone is inhibited and we absorb less sodium and water and pee it out
