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Aug 17, 2023 · The terminal arborization of the right branch supplies the papillary muscle and recurs to supply the rest of the ventricular wall. The left bundle branch or crus sinistrum (Latin) branches from the atrioventricular bundle at the start of the muscular interventricular septum. It is made up of numerous small fascicles that become flattened sheets.
The T wave (and a portion of the QRS complex) measure the electrical activity associated with repolarization, the physiological reset required to prepare for the next cardiac cycle. Figure 17.3.5 17.3. 5: Electrocardiogram. A normal tracing shows the P wave, QRS complex, and T wave. Also indicated are the PR, QT, QRS, and ST intervals, plus the ...
- Sinoatrial Node
- Atrioventricular Node
- Atrioventricular Bundle
- Purkinje Fibres
The sinoatrial (SA) nodeis a collection of specialised cells (pacemaker cells), and is located in the upper wall of the right atrium, at the junction where the superior vena cava enters. These pacemaker cells can spontaneously generateelectrical impulses. The wave of excitation created by the SA node spreads via gap junctions across both atria, res...
After the electrical impulses spread across the atria, they converge at the atrioventricular node– located within the atrioventricular septum, near the opening of the coronary sinus. The AV node acts to delay the impulses by approximately 120ms, to ensure the atria have enough time to fully eject blood into the ventricles before ventricular systole...
The atrioventricular bundle(bundle of His) is a continuation of the specialised tissue of the AV node, and serves to transmit the electrical impulse from the AV node to the Purkinje fibres of the ventricles. It descends down the membranous part of the interventricular septum, before dividing into two main bundles: 1. Right bundle branch– conducts t...
ThePurkinje fibres(sub-endocardial plexus of conduction cells) are a network of specialised cells. They are abundant with glycogen and have extensive gap junctions. These cells are located in thesubendocardial surfaceof the ventricular walls, and are able to rapidly transmit cardiac action potentials from the atrioventricular bundle to the myocardi...
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Oct 4, 2019 · These inner and outer layers of the heart, respectively, surround the cardiac muscle tissue and separate it from the blood and other organs. Cardiac muscle is made from sheets of cardiac muscle cells. These cells, unlike skeletal muscle cells, are typically unicellular and connect to one another through special intercalated discs.
May 10, 2020 · The heart has two main types of cells: 1. Conducting cells: generate and propagate electrical impulses. Contractile (muscle) cells: contract following receipt of electrical impulses. These cells can also propagate and, on occasion, generate electrical impulses. Both conducting and specialised muscle cells form the hearts conduction system and ...
Cardiac muscle cells branch freely. A junction between two adjoining cells is marked by a critical structure called an intercalated disc, which helps support the synchronized contraction of the muscle (Figure 19.2.1 b). The sarcolemmas from adjacent cells bind together at the intercalated discs.
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Nov 23, 2022 · Characteristics. Cardiac muscle tissue, also known as myocardium, is a structurally and functionally unique subtype of muscle tissue located in the heart, that actually has characteristics from both skeletal and muscle tissues. It is capable of strong, continuous, and rhythmic contractions that are automatically generated.
