Sinus Node
Sinus Node - Related Videos
11:07
High-resolution Optical Mapping of the Mouse Sino-atrial Node
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Cited by 17 •
2016
Here, we present a protocol for optical mapping of electrical activity from the mouse right atrium and especially the sino-atrial node, at a high spatial and temporal resolution.
08:06
Lymph Node Exam
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2023
Source: Richard Glickman-Simon, MD, Assistant Professor, Department of Public Health and Community Medicine, Tufts University School of Medicine, MA The lymphatic system has two main functions: to return extracellular fluid back to the venous circulation and to expose antigenic substances to the immune system. As the collected fluid passes through lymphatic channels on its way back to the systemic circulation, it encounters multiple nodes consisting of highly concentrated clusters of...
08:46
Nose, Sinuses, Oral Cavity and Pharynx Exam
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2023
Source: Richard Glickman-Simon, MD, Assistant Professor, Department of Public Health and Community Medicine, Tufts University School of Medicine, MA This video provides an overview of sinus, nose, and throat examinations. The demonstration begins with a brief overview of the anatomy of the region. The upper third of the nose is bony, and the bottom two-thirds are cartilaginous. Air entering the nares passes through the nasal vestibules and into the narrow passageway between the nasal septum...
06:43
Quantitative Analysis and Characterization of Atherosclerotic Lesions in the Murine Aortic Sinus
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Cited by 51 •
2013
We describe procedures to quantify and characterize atherosclerotic lesions in mouse models using precision sectioning of the aortic sinus and ascending aorta combined with histochemical and immunohistochemical analysis.
07:34
Establishment of a Modified Ferric Chloride-Induced Superior Sagittal Sinus Thrombosis
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2025
This study presents a protocol for establishing a reproducible, minimally invasive rat model of superior sagittal sinus thrombosis induced by ferric chloride, utilizing a silk-suture method in combination with laser speckle contrast imaging and high-resolution ultrasound for evaluation.
FAQs
The key electrical event is spontaneous depolarization, produced by ion movement across the pacemaker-cell membrane. Because this activity occurs without an externally supplied impulse, the cells can repeatedly initiate electrical signals. The resulting timing establishes the starting point for each heartbeat and allows the cardiac rhythm to continue between individual beats.
The autonomic nervous system adjusts sinus node rate according to changing physiological conditions. Activity and stress can require a different rhythm than rest, so autonomic regulation modifies the pace of impulse generation rather than replacing the node’s pacemaker role. This adjustment helps relate heart rate to the body’s current state.
After initiation, the electrical impulse spreads through the atria before reaching the atrioventricular node. This pathway places the sinus node at the beginning of the cardiac conduction sequence and makes atrial spread an important part of coordinated signaling. Disturbances affecting this sequence can therefore contribute to irregular rhythm assessment in clinical practice.
Clinicians evaluate sinus node function when a patient has bradycardia, an irregular rhythm, or possible sick sinus syndrome. The assessment focuses on whether the node is generating and regulating cardiac impulses appropriately. These concerns make sinus node function clinically important for identifying conduction problems and guiding decisions about continued evaluation or treatment.
Persistent sinus node dysfunction indicates that the heart’s normal rhythm-setting activity may not be maintained adequately over time. In the clinical context, ongoing dysfunction is more significant than an isolated concern because it can require treatment. The overview identifies an artificial pacemaker as a possible management approach when dysfunction persists.
An artificial pacemaker may be considered when sinus node dysfunction remains persistent and affects the heart’s ability to maintain an appropriate rhythm. The device represents a treatment response to ongoing rhythm-setting failure rather than a tool for routine sinus node assessment. Clinical evaluation of bradycardia, irregular rhythms, or sick sinus syndrome helps establish that context.