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The cardiac skeleton binds several bands of dense connective tissue, as collagen, that encircle the bases of the pulmonary trunk, aorta, and all four heart valves. [2] While not a traditionally or "true" or rigid skeleton , it does provide structure and support for the heart, as well as isolate the atria from the ventricles.
The trabeculae carneae (columnae carneae or meaty ridges) are rounded or irregular muscular columns which project from the inner surface of the right and left ventricle of the heart. [1] These are different from the pectinate muscles, which are present in the atria of the heart. In development, trabeculae carneae are among the first of the ...
Plant anatomy or phytotomy is the general term for the study of the internal structure of plants.Originally, it included plant morphology, the description of the physical form and external structure of plants, but since the mid-20th century, plant anatomy has been considered a separate field referring only to internal plant structure.
In plants, organogenesis occurs continuously and only stops when the plant dies. In the shoot, the shoot apical meristems regularly produce new lateral organs (leaves or flowers) and lateral branches. In the root, new lateral roots form from weakly differentiated internal tissue (e.g. the xylem-pole pericycle in the model plant Arabidopsis ...
Ryanodine receptors mediate the release of calcium ions from the sarcoplasmic reticulum and endoplasmic reticulum, an essential step in muscle contraction. [1] In skeletal muscle, activation of ryanodine receptors occurs via a physical coupling to the dihydropyridine receptor (a voltage-dependent, L-type calcium channel), whereas, in cardiac muscle, the primary mechanism of activation is ...
The general structure of a cardiac glycoside consists of a steroid molecule attached to a sugar and an R group. [4] The steroid nucleus consists of four fused rings to which other functional groups such as methyl, hydroxyl, and aldehyde groups can be attached to influence the overall molecule's biological activity. [4]
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.
A germination rate experiment. Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. [1]Plant physiologists study fundamental processes of plants, such as photosynthesis, respiration, plant nutrition, plant hormone functions, tropisms, nastic movements, photoperiodism, photomorphogenesis, circadian rhythms, environmental stress physiology, seed ...