Glossary of Physiology Terms – R
Resting membrane potential
Definition:
The voltage difference across a cell plasma membrane in the resting or quiescent state. It is also simply referred to as the resting potential (
Vrest). The value of the resting membrane potential varies from cell to cell. Depending on the cell type, it can range from −90 mV to −20 mV.
For example,
Vrest is −90 mV in skeletal and cardiac muscle cells as well as in astrocytes. In a typical neuron,
Vrest is approximately −70 mV. In many non-excitable cells,
Vrest ranges from −60 to −50 mV. In photoreceptors,
Vrest is about −20 mV.
See also:
Resting membrane potential
Retrograde
Definition:
Moving from the axon terminal back toward the neuronal cell body.
Related glossary terms/phrases:
Anterograde
Right atrioventricular valve
Definition:
The one-way valve between the right atrium and right ventricle of the heart. It is also known as the
tricuspid valve.
The direction of blood flow through the right atrioventricular valve is from the right atrium to the right ventricle.
Related glossary terms/phrases:
Tricuspid valve
Posted: Tuesday, July 3, 2012
Last updated: Saturday, January 10, 2015