Sometimes you may have atrial flutter that develops into atrial fibrillation and vice versa. The risk factors for and the symptoms and causes of atrial flutter are similar to those of atrial fibrillation. For example, strokes are also a concern in someone with atrial flutter. As with atrial fibrillation, atrial flutter is usually not life-threatening when it's properly treated.
Nerves and Nerve Types. There three types of nerves in the central nervous system: motor neurons, sensory neurons and autonomic neurons. Motor nerves send impulses or signals from the brain and spinal cord to all of the muscles in the body.
2. List the three types of contractile cells in the body. Skeletal muscle cells, cardiac muscle cells, and smooth muscle cells. 3-5. Give the shapes for each of the three muscle types. Skeletal muscles are elongated, cardiac muscles are branched, and smooth muscles are spindle-shaped.6-11.. List the three types of contractile cells in the body. Skeletal muscle cells, cardiac muscle cells, and smooth muscle cells. 3-5. Give the shapes for each of the three muscle types. Skeletal muscles are elongated, cardiac muscles are branched, and smooth muscles are spindle-shaped. 6-11.