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The beta-2 adrenergic receptor (β 2 adrenoreceptor), also known as ADRB2, is a cell membrane-spanning beta-adrenergic receptor that binds epinephrine (adrenaline), a hormone and neurotransmitter whose signaling, via adenylate cyclase stimulation through trimeric G s proteins, increases cAMP, and, via downstream L-type calcium channel interaction, mediates physiologic responses such as smooth ...
Beta 2-adrenergic agonists, also known as adrenergic β 2 receptor agonists, are a class of drugs that act on the β 2 adrenergic receptor. Like other β adrenergic agonists , they cause smooth muscle relaxation. β 2 adrenergic agonists' effects on smooth muscle cause dilation of bronchial passages , vasodilation in muscle and liver ...
When NE is released into the synapse, it feeds back on the α 2 receptor, causing less NE release from the presynaptic neuron. This decreases the effect of NE. There are also α 2 receptors on the nerve terminal membrane of the post-synaptic adrenergic neuron. Actions of the α 2 receptor include: decreased insulin release from the pancreas [19]
Vascular smooth muscle contracts or relaxes to change both the volume of blood vessels and the local blood pressure, a mechanism that is responsible for the redistribution of the blood within the body to areas where it is needed (i.e. areas with temporarily enhanced oxygen consumption).
Heart failure with preserved ejection fraction (HFpEF) is a form of heart failure in which the ejection fraction – the percentage of the volume of blood ejected from the left ventricle with each heartbeat divided by the volume of blood when the left ventricle is maximally filled – is normal, defined as greater than 50%; [1] this may be measured by echocardiography or cardiac catheterization.
Beta blockers interfere with the binding to the receptor of epinephrine and other stress hormones and thereby weaken the effects of stress hormones. Some beta blockers block activation of all types of β-adrenergic receptors and others are selective for one of the three known types of beta receptors, designated β 1, β 2 and β 3 receptors.
Over time, these processes can stiffen the vasculature. For these reasons, older age is listed as a major risk factor for atherosclerosis. [16] Specifically, the risk of atherosclerosis increases for men above 45 years of age and women above 55 years of age. [17]
As a result, the heart has a hard time pumping blood through the lungs, and the blood vessels eventually undergoes fibrosis. The increased workload on the heart causes hypertrophy of the right ventricle, which leads less blood being pump through the lungs and decreased blood to the left side of the heart.