low doses of multiple drugs are unlikely to be as effective as 2 standard doses of an angiotensin receptor blocker to reduce blood pressure

most patients reach target blood pressure with monotherapy

it is best to take a standard dose of a first-line antihypertensive medication, and to escalate the dose if blood pressure target is not achieved.

low dose combination therapy effectively lowers blood pressure and reduces unwanted side-effects

Bundle of His

Sinoatrial node

Rostral mediolateral medulla

Nucleus tractus solitarius

Acetylcholine, that acts on nicotinic receptors

Noradrenaline, that acts on adrenoreceptors

Noradrenaline, that acts on muscarinic receptors

Acetylcholine, that acts on muscarinic receptors

Decreases due to muscle contraction

Increases due to vasoconstriction of blood vessels

Increases due to pooling of blood

Decreases due to increased return of blood to the heart

increased urinary salt and water excretion

increased salt and water appetite

movement of fluid into the interstitial space

vasodilation

 increased central venous pressure

increased cardiac filling

decreased total peripheral resistance

 decreased central venous pressure

atrial natriuretic peptide is released, which causes contraction of the vena cava.

changes in the pattern of breathing lead to increases in pulmonary vascular resistance.

a positive pressure is applied to the lower body, which compresses large veins, so increasing the volume of blood in the vena cava in the chest.

water is absorbed via the skin, so increasing total blood volume.

sympathetic activity increases, causing vasodilatation

the hypothalamus signals the nucleus ambiguus allowing heart rate to increase

para-sympathetic activity increases heart rate

the pituitary signals the nucleus ambiguus allowing heart rate to decrease

acetylcholine

angiotensin

gamma aminobutyric acid

an excitatory amino acid

blood flow is increased by a reduction in hematocrit

The vasoconstrictor angiotensin II contributes to the phenomenon of reactive hyperemia

In the absence of a change in vascular resistance, an increase in arterial blood pressure from 70 to 175 mmHg will halve blood flow

According to Poiseuille's Law, the rate of blood flow is inversely proportional to the fourth power of the radius