The term "reflex diastole" is spelled with the IPA phonetic transcription /riː.flɛks daɪˈæstəli/. "Reflex" is pronounced with a long "e" sound as in "re-," followed by "fl" and ending with a hard "ks" sound. "Diastole" is pronounced with a long "i" sound as in "di-," followed by "as" pronounced with a short "a," and ending with a soft "li" sound. This term describes the relaxation of the heart's chambers due to the activation of a reflex pathway.
Reflex diastole refers to the relaxation or dilation phase of the cardiac cycle that occurs as a response to specific reflexes, particularly those involving the autonomic nervous system.
During reflex diastole, the cardiac muscles relax, allowing the chambers of the heart to fill with blood. This is an essential phase in the cardiac cycle as it allows the heart to receive a fresh supply of oxygenated blood from the lungs, which will later be pumped out to the rest of the body during systole (the contraction phase of the cardiac cycle). Throughout this phase, several reflex mechanisms contribute to the regulation of cardiac function.
One vital reflex involved in reflex diastole is the baroreceptor reflex, which monitors changes in blood pressure. When blood pressure drops, the baroreceptors detect this change and stimulate the autonomic nervous system to increase heart rate and contractility, leading to a decrease in diastole duration. Similarly, the Bainbridge reflex, or atrial reflex, is another mechanism that influences reflex diastole. It responds to an increase in atrial stretch, typically occurring due to an increase in venous return, and triggers an increase in heart rate and contraction strength, thereby reducing the duration of diastole.
Overall, reflex diastole plays a crucial role in maintaining cardiac efficiency and ensuring an adequate supply of oxygenated blood to the body's tissues.
Reflex vasodilatation; when the skin is stroked with a pressure of about two ounces by a hard smooth object, such as the end of a pen-holder, there is first a reddened line followed in a few seconds by a white line lasting a minute or two.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The term "reflex diastole" does not have a specific etymology on its own as it is a combination of two separate words: "reflex" and "diastole".
1. Reflex: The word "reflex" is derived from the Latin word "reflexus", which means "bent back" or "recoiled". It originated from the verb "reflectere", which combines "re-" (back) and "flectere" (to bend). English, "reflex" is commonly used to describe an involuntary reaction or response to a stimulus.
2. Diastole: The word "diastole" comes from the Greek word "diastolē", meaning "a separation" or "a dilation". It is derived from the verb "diastellein", which combines "dia-" (through) and "stellein" (to set or bring together).