Search results
Results from the WOW.Com Content Network
Heart rate is governed by many influences from the autonomic nervous system. The Purkinje fibers do not have any known role in setting heart rate unless the SA node is compromised (when they can act as pacemaker cells). [7] They are influenced by electrical discharge from the sinoatrial node.
These calcium ions bind to and open more calcium channels (called ryanodine receptors) located on the sarcoplasmic reticulum within the cell, allowing the flow of calcium out of the SR. These calcium ions are responsible for the contraction of the heart. Calcium also activates chloride channels called I to2, which allow Cl − to enter the cell ...
The bundle of His (BH) [1]: 58 or His bundle (HB) [1]: 232 (/ h ɪ s / "hiss" [2]) is a collection of heart muscle cells specialized for electrical conduction.As part of the electrical conduction system of the heart, it transmits the electrical impulses from the atrioventricular node (located between the atria and the ventricles) to the point of the apex of the fascicular branches via the ...
The conduction system consists of specialized heart muscle cells, situated within the myocardium. [3] There is a skeleton of fibrous tissue that surrounds the conduction system which can be seen on an ECG. Dysfunction of the conduction system can cause irregular heart rhythms including rhythms that are too fast or too slow.
Transmission of a cardiac action potential through the heart's conduction system. The normal rhythmical heart beat, called sinus rhythm, is established by the heart's own pacemaker, the sinoatrial node (also known as the sinus node or the SA node). Here an electrical signal is created that travels through the heart, causing the heart muscle to ...
Autoregulation is a process within many biological systems, resulting from an internal adaptive mechanism that works to adjust (or mitigate) that system's response to stimuli. While most systems of the body show some degree of autoregulation, it is most clearly observed in the kidney, the heart, and the brain. [1]
Cardiac physiology or heart function is the study of healthy, unimpaired function of the heart: involving blood flow; myocardium structure; the electrical conduction system of the heart; the cardiac cycle and cardiac output and how these interact and depend on one another.
The organs known as the accessory digestive organs are the liver, gall bladder and pancreas. Other components include the mouth , salivary glands , tongue , teeth and epiglottis . The largest structure of the digestive system is the gastrointestinal tract (GI tract).