Where skeletal muscle is voluntary, cardiac muscle is autorhythmic (beats involuntarily; generates its own action potentials). 3. Smooth muscle: refers to the muscles that are controlled involuntarily by the brain, like those attached to the base of hair follicles or in the walls of the gastro-intestinal tract.The muscle has a single nucleus in the middle of the cell. Skeletal and cardiac muscle are types of straited muscle.here skeletal muscle is voluntary, cardiac muscle is autorhythmic (beats involuntarily; generates its own action potentials). 3. Smooth muscle: refers to the muscles that are controlled involuntarily by the brain, like those attached to the base of hair follicles or in the walls of the gastro-intestinal tract.
When this results in irritation or damage to the adjacent nerves at the T4 level and the patient experiences diffuse arm pain, pins and needles or numbness in the upper arm the condition is known as T4 syndrome. Causes of T4 syndrome. T4 syndrome typically occurs due to injury to the facet joints or disc at T4 which then affects the nerve root at that level. Injury to these structures can occur during excessive bending, lifting, arching, or twisting movements or due to poor posture.
Dermatomes exist for each of these spinal nerves, except the first cervical spinal nerve. Sensory information from a specific dermatome is transmitted by the sensory nerve fibers to the spinal nerve of a specific segment of the spinal cord. The C1-C7 nerve roots emerge above their respective vertebrae; the C8 nerve root emerges between the C7 and T1 vertebrae .