In humans, the yolk sac is the
site of origin for blood cells and primordial germ cells. The human yolk sac is
a membrane located outside the embryo and it is connected by a tube through the
umbilical opening to the embryo's midgut. The yolk sac serves as an early site
for the formation of blood and in time, is incorporated into the primitive gut
of the embryo.
Answer:
The best answer to the question: These cellular structures are utilized in strong involuntary muscle contractions and transmission of electrical impulses, would be: T-Tubules.
Explanation:
In both skeletal and cardiac muscle, not smooth muscle, because of the way that the muscle fibers are conformed into tight bundles of sarcomeres (skeletal muscle) and myocardiocytes (cardiac muscle), there is a need for a series of structures that will ensure that when there is a stimulus from the nervous systems, these stimulus will propagate to all the cells in the fibers, and not just one.
Aside from counting with a neuromuscular motor plate, which will receive the neurotransmitter from the nerve endings and produce the appropriate reactions, as well as propagate that reaction to all the cells that are being stimulated, muscle fibers also have a structure known as T-Tubules. T-Tubules are formations much like roadways of cell plasma membrane that connect not just one, but all the cells within a muscle fiber so that once a stimulus comes, all the cells will initiate the process of calcium release and action potential propagation. These T-Tubules will ensure that electrical impulses reach all muscle cells and that all cells react at the same time as needed.
Cohesion is water sticking to water. adhesion is water sticking to another thing, think of it as you're adding something to the water molecules. add-hesion
<h3>Playing the role as ” procoter of the help beads ”, the sea otther is able to mantian a balance of the ecosystem , naturally by conusiming sea urchins ...</h3>
<h2>I hope it is helpful for you....</h2>
Answer:
True
Explanation:
It can rapidly increase if the environment is good for them
