The symptoms of a stroke are different, depending on where in the brain the stroke is located, and doctors can use the symptoms to pinpoint the site of the stroke. In the case of a brain stem stroke, the patient often experiences vertigo, slurred speech, and difficulty speaking.
The smallest functional unit in a myofibril is a sarcomere. A sarcomere is composed of thin (actin) and thick (myosin) filaments. Actin slides past myosin when the muscle contracts.
Muscle cells, ensheathed by endomysium, consist of many fibrils (or myofibrils), and these myofibrils are made up of long protein molecules called myofilaments. There are two types of myofilaments in myofibrils: thick myofilaments and thin myofilaments. Source: Wikipedia Muscle contraction Source: Hopkins (2005). - Because skeletal muscle is voluntary muscle, contraction requires a nervous impulse. So, step 1 in contraction is when the impulse is transferred from a neuron to the SARCOLEMMA of a muscle cell. 2 - The impulse travels along the SARCOLEMMA and down the T-TUBULES.