The Myocardium
Cardiac muscle is found only in the heart. Cardiac muscle contains the proteins actin and myosin. All the other muscles are smooth or skeletal.
The heart is a muscle, and as such has multiple tissues. The main tissue is cardiac muscle cells. These are striated, branched muscle cells held together with intercalated discs. Connective tissue forms a sac around the heart, and epithelial tissue forms blood vessels within the heart. Therefore, the heart contains all four types of tissue. It is mostly muscle tissue. Connective tissue forms a protective sac and holds the heart together, epithelial tissue forms the blood vessels, and nervous tissue carries impulses to and away from the heart. this is all true! ~Trenasian was here!
yes it increases it by having epinephrine and//or norepinephrine bind to beta 1 receptors on the ventricle of the heart which causes a second messanger system of cyclic AMP to phosphorylate 1) voltage gated calcium channels to stay open longer so more calcium comes inside cell from outside so more Ca can be stored in sarcoplasmic reticulm (SR) but also more interaction between actin and myosin. 2) phosphorylates calcium pump which increases its activity so more calcium can be stored in SR so there is a bigger force (bigger Stroke volume). AND also removes calcium from cytosol faster (calcium back into cisterna), which shortens the duration of refractory period which increases heart rate.
Enzymes of the heart.ANSWER 2 Different Cardiac EnzymesThe heart is a muscular pump. When a person experiences a heart attack, a portion of the heart muscle is damaged, causing symptoms such as shortness of breath, chest pain that can radiate, nausea, vomiting, dizziness and sweating. One way of determining whether these symptoms are the result of actual heart dysfunction or heart attack is through blood tests that evaluate the cardiac enzymes. When the heart muscle is damaged, it releases these cardiac enzymes into the bloodstream. When a blood test measures increased cardiac enzymes, it is an indicator that actual damage has resulted.Creatinine PhosphokinaseAccording to the American Heart Association, the most common cardiac enzyme to be tested when a heart attack is suspected is creatinine phosphokinase (CPK). This enzyme is normally present in small amounts in the blood and is released by all muscle tissue in the body--skeletal, cardiac and smooth muscle. When CPK is elevated, it indicates muscle damage and further tests can be ordered. Often, when a patient enters a medical facility complaining of heart attack symptoms, elevated CPK may be the only indicator that a heart attack has actually occurred. Sometimes CPK will not read high in the blood until 24 hours after the heart attack, so careful monitoring for a period of time is required. CPK-MBCPK-MB is a fractional piece of creatinine phosphokinase. Although CPK is released from all muscle tissue in the body, CPK-MB is released only from damaged heart tissue, so it is much more accurate in determining whether a heart attack has occurred. CPK-MB is diagnostic for a heart attack even in the presence of a normal EKG. CPK-MB may not be elevated in the blood until 12 to 24 hours after a heart attack. Increased accuracy in diagnosis may be found by repeating the CPK-MB blood test multiple times over the first 24 hours, looking for changes in levels. TroponinsTroponins, proteins found in muscle tissue, help modulate actin and myosin, which are responsible for muscle contraction. Some very specific troponins have been identified as occurring only in the heart muscle, specifically Troponin T and Troponin I. These can be tested for and measured. These troponins are normally present in very low quantities in the blood. When elevated, they can indicate even very minor heart tissue damage that may not show up with a CPK test. Troponin typically shows up in the blood as elevated within 12 hours after a heart attack. By measuring Troponin and CPK, it is possible to diagnose a heart attack even when other tests may be negative.
Coronary heart diseaseCardiomyopathyCardiovascular diseaseIschemic heart diseaseHypertensive heart diseaseInflammatory heart diseaseValvular heart diseaseHeart Cancer
The phase of the cardiac cycle caused by the sliding of actin and myosin is systole. During systole, the heart muscle contracts to pump blood out of the heart into the circulation. This contraction is driven by the sliding of actin and myosin filaments in the cardiac muscle cells.
Actually, intercalated discs and striations are unique features of cardiac muscle, not skeletal muscle. These structures help cardiac muscle cells work together as a functional unit, allowing the heart to contract efficiently. Skeletal muscle lacks intercalated discs and striations are more organized in a linear pattern.
The structure of the heart is very complex. Cardiac myocytes and intercalated discs follow the function of cardiac muscle tissue and the heart make up part of this very complex system
Cardiac muscle tissue has intercalated discs, which are specialized structures that help with communication and coordination of muscle contractions in the heart.
inside Valerie's heart!! AWWWWW HOW CUTE! YAY FOR JACKIE
The intercalated discs are specialized structures in cardiac muscle that allow for uniform contraction. They contain gap junctions, which allow for rapid electrical communication between cells, ensuring synchronous contraction of the heart muscle. Additionally, desmosomes in the intercalated discs help to physically link neighboring cardiac muscle cells, allowing for force transmission during contraction.
Intercalated discs are unique to cardiac muscle tissue, providing a strong connection between adjacent cells and allowing for coordinated contraction of the heart. Skeletal muscle tissue lacks intercalated discs since individual muscle fibers act independently.
Intercalated discs are very complex structures and have great significance in terms of the workings of the myocardium. These discs create a high degree of interconnection between the myocardial cells.
Intercalated discs in cardiac muscle cells help synchronize their contractions by allowing electrical signals to pass quickly between cells. This communication ensures that the heart muscle contracts in a coordinated manner, leading to efficient pumping of blood.
Intercalated discs are found in cardiac muscle tissue, specifically at the junction between adjacent cardiomyocytes (heart muscle cells). They contain specialized structures that facilitate communication and coordination between cells, allowing for synchronized contraction of the heart.
Intercalated discs in cardiac muscle serve as specialized structures that help connect individual heart muscle cells, or cardiomyocytes, together. They play a crucial role in coordinating the contraction of the heart by allowing for rapid communication and synchronization between adjacent cells. This enables the heart to contract as a single, cohesive unit, ensuring efficient and effective pumping of blood throughout the body.
Cardiac muscle is found in the heart and is involuntary, meaning it contracts without conscious control. It has intercalated discs for rapid communication between cells. Skeletal muscle is attached to bones and is voluntary, allowing for conscious movement. It lacks intercalated discs but has striations for organized contraction.