BloodBlood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the circulatory system is also known as peripheral blood, and the blood cells it carries, peripheral blood cells. Blood is composed of blood cells suspended in blood plasma.
Striated muscle tissueStriated muscle tissue is a muscle tissue that features repeating functional units called sarcomeres. The presence of sarcomeres manifests as a series of bands visible along the muscle fibers, which is responsible for the striated appearance observed in microscopic images of this tissue. There are two types of striated muscle: Cardiac muscle (heart muscle) Skeletal muscle (muscle attached to the skeleton) Striated muscle tissue contains T-tubules which enables the release of calcium ions from the sarcoplasmic reticulum.
Right bundle branch blockA right bundle branch block (RBBB) is a heart block in the right bundle branch of the electrical conduction system. During a right bundle branch block, the right ventricle is not directly activated by impulses travelling through the right bundle branch. The left ventricle, however, is still normally activated by the left bundle branch. These impulses are then able to travel through the myocardium of the left ventricle to the right ventricle and depolarize the right ventricle this way.
Mitral valve prolapseMitral valve prolapse (MVP) is a valvular heart disease characterized by the displacement of an abnormally thickened mitral valve leaflet into the left atrium during systole. It is the primary form of myxomatous degeneration of the valve. There are various types of MVP, broadly classified as classic and nonclassic. In severe cases of classic MVP, complications include mitral regurgitation, infective endocarditis, congestive heart failure, and, in rare circumstances, cardiac arrest.
Tricuspid regurgitationTricuspid regurgitation (TR), also called tricuspid insufficiency, is a type of valvular heart disease in which the tricuspid valve of the heart, located between the right atrium and right ventricle, does not close completely when the right ventricle contracts (systole). TR allows the blood to flow backwards from the right ventricle to the right atrium, which increases the volume and pressure of the blood both in the right atrium and the right ventricle, which may increase central venous volume and pressure if the backward flow is sufficiently severe.
Fourth heart soundThe fourth heart sound or S4 is an extra heart sound that occurs during late diastole, immediately before the normal two "lub-dub" heart sounds (S1 and S2). It occurs just after atrial contraction and immediately before the systolic S1 and is caused by the atria contracting forcefully in an effort to overcome an abnormally stiff or hypertrophic ventricle. This produces a rhythm classically compared to the cadence of the word "Tennessee." One can also use the phrase "A-stiff-wall" to help with the cadence (a S4, stiff S1, wall S2), as well as the pathology of the S4 sound.
CardiomegalyCardiomegaly (sometimes megacardia or megalocardia) is a medical condition in which the heart becomes enlarged. It is more commonly referred to simply as "having an enlarged heart". It is usually the result of underlying conditions that make the heart work harder, such as obesity, heart valve disease, high blood pressure (hypertension), and coronary artery disease. Cardiomyopathy is also associated with cardiomegaly. Cardiomegaly can be serious and can result in congestive heart failure.
