Atrial volume receptors (also known as Veno-atrial stretch receptors) are low pressure

baroreceptor Baroreceptors (or archaically, pressoreceptors) are stretch receptors that sense blood pressure. Thus, increases in the pressure of blood vessel triggers increased action potential generation rates and provides information to the central nervous s ...

s that are found in the

atria Atria may refer to: Science *Atrium (heart) (plural: atria), an anatomical structure of the heart *Atria (genus), a flatworm genus in the family Dendrocoelidae * Atria (star) or Alpha Trianguli Australis, a star in the constellation Triangulum Aus ...

of the heart. They are

myelinated Myelin Sheath ( ) is a lipid-rich material that in most vertebrates surrounds the axons of neurons to insulate them and increase the rate at which electrical impulses (called action potentials) pass along the axon. The myelinated axon can be lik ...

vagal The vagus nerve, also known as the tenth cranial nerve (CN X), plays a crucial role in the autonomic nervous system, which is responsible for regulating involuntary functions within the human body. This nerve carries both sensory and motor fibe ...

fibres in the

endocardium The endocardium (: endocardia) is the innermost layer of tissue that lines the chambers of the heart. Its cells are embryologically and biologically similar to the endothelial cells that line blood vessels. The endocardium also provides prot ...

found at the junction between atria and the vena cava/pulmonary vein. When these receptors detect a blood volume increase in the atria, the atrial stretch triggers the release of Atrial Natriuretic Peptide (ANP), and a signal is transmitted from the receptors to the

hypothalamus The hypothalamus (: hypothalami; ) is a small part of the vertebrate brain that contains a number of nucleus (neuroanatomy), nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrin ...

in the brain. The ANP causes increased natriuresis, while the hypothalamus, in turn, decreases the production of

vasopressin Mammalian vasopressin, also called antidiuretic hormone (ADH), arginine vasopressin (AVP) or argipressin, is a hormone synthesized from the ''AVP'' gene as a peptide prohormone in neurons in the hypothalamus, and is converted to AVP. It ...

(also known as ADH, AVP, or arginine vasopressin). These receptors also cause a renal vasodilation, resulting in increased diuresis. This decreases the blood volume, resulting in the decrease of blood pressure.There are two types, type A is activated by atrial wall tension in atrial contraction (during the a wave of the atrial pressure curve), type B is activated by atrial stretch during atrial filling (with the v pressure wave). They can display

hysteresis Hysteresis is the dependence of the state of a system on its history. For example, a magnet may have more than one possible magnetic moment in a given magnetic field, depending on how the field changed in the past. Plots of a single component of ...

References

Cardiac anatomy Blood pressure {{circulatory-stub

See also

References