17.3: Cardiac Muscle - Medicine LibreTexts
2022年7月27日 · There are two major types of cardiac muscle cells: myocardial contractile cells and myocardial conducting cells. The myocardial contractile cells constitute the bulk (99 percent) of the cells in the atria and ventricles. Contractile cells conduct impulses and are responsible for contractions that pump blood through the body.
10.8: Cardiac Muscle Tissue - Medicine LibreTexts
2023年2月24日 · Cardiac muscle fibers cells also are extensively branched and are connected to one another at their ends by intercalated discs. An intercalated disc allows the cardiac muscle cells to contract in a wave-like pattern so that the heart can work as a pump. Figure 10.8.1 10.8. 1: Cardiac Muscle Tissue Cardiac muscle tissue is only found in the heart.
17.3: Cardiac Muscle and Electrical Activity
2024年8月19日 · Figure 17.3.4 17.3. 4 show the spread of the electrical wave through these structures and the myocardial contractile cells. Figure 17.3.4 17.3. 4: Cardiac Conduction. (1) The sinoatrial (SA) node and the remainder of the conducting system are at rest. (2) The SA node initiates the electrical wave, which sweeps across the atria.
17.3: Cardiac Muscle and Electrical Activity - Medicine LibreTexts
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 ...
17.3A: Mechanism and Contraction Events of Cardiac Muscle Fibers
In cardiac, skeletal, and some smooth muscle tissue, contraction occurs through a phenomenon known as excitation contraction coupling (ECC). ECC describes the process of converting an electrical stimulus from the neurons into a mechanical response that facilitates muscle movement. Action potentials are the electrical stimulus that elicits the ...
19.2: Cardiac Muscle and Electrical Activity
2022年5月13日 · Figure \(\PageIndex{1}\): Cardiac Muscle. (a) Cardiac muscle cells have myofibrils composed of myofilaments arranged in sarcomeres, T tubules to transmit the impulse from the sarcolemma to the interior of the cell, numerous mitochondria for energy, and intercalated discs that are found at the junction of different cardiac muscle cells.
3.4: Distinguishing Between The Three Types of Muscle Tissue
One cardiac muscle fiber is the material between two intercalated discs. Cardiac muscle fibers are mononucleate , with only one nucleus per fiber, and they can sometimes be branched . Smooth muscle is found in the walls of internal organs, such as the organs of the digestive tract, blood vessels, and others.
9.1A: Structure and Function of the Muscular System
The Musculoskeletal System. The muscular system is made up of muscle tissue and is responsible for functions such as maintenance of posture, locomotion and control of various circulatory systems. This includes the beating of the heart and the movement of food through the digestive system. The muscular system is closely associated with the ...
17.3B: Microscopic Anatomy - Medicine LibreTexts
A sarcomere is the basic unit of muscle tissue in both cardiac and skeletal muscle. Sarcomeres appear under the microscope as striations, with alternating dark and light bands. Sarcomeres are connected to a plasma membrane, called a sarcolemma, by T-tubules, which speed up the rate of depolarization within the sarcomere.
3.5: Muscle Tissue - Medicine LibreTexts
2024年9月15日 · The cardiac muscle pumps blood through the body and is under involuntary control. The attachment junctions hold adjacent cells together across the dynamic pressures changes of the cardiac cycle. Smooth muscle tissue contraction is responsible for involuntary movements in the internal organs. It forms the contractile component of the digestive ...