Final answer:
Muscle cells directly cause movement by contracting and generating a pulling force. The characteristic of muscle cells that causes movement is their ability to contract and create tension in response to neural stimulation.
Step-by-step explanation:
Muscle cells are contractile, meaning they can shorten and generate a pulling force. When attached between two movable objects, such as bones, contractions of the muscles cause the bones to move. This characteristic of muscle cells directly causes movement.
The characteristic of muscle cells that causes movement is their ability to contract and create tension in response to neural stimulation. This process is part of the sliding filament model of contraction and involves the action of actin and myosin within the muscle cells.
The characteristic of the muscle cell that directly causes movement is its ability to contract. Muscle cells, or myocytes, can shorten and generate tension in response to stimulation, a process governed by the sliding filament model of contraction. In this model, a neurotransmitter called acetylcholine (ACh) binds at the neuromuscular junction (NMJ), causing an action potential that travels along the sarcolemma to trigger the release of calcium from the sarcoplasmic reticulum (SR). This in turn activates the actin and myosin within the muscle cells to interact, causing the muscle to contract and facilitate movement.
Skeletal muscles, which are under voluntary control, are composed of long cells with multiple nuclei and striations from the arrangement of actin and myosin. Conversely, smooth muscles, controlling involuntary movements, are non-striated and operate under a different mechanism. However, both skeletal and smooth muscle contractions involve the formation of actin-myosin cross-bridges, allowing for skeletal movement when these muscles pull on bones.