Motor Behavior: Muscle Contraction and Coordination

Resting Membrane Potential

Voltage difference across a neuron's membrane.

Membrane Potential

Essential for nerve impulse conduction.

Cations

Positively charged ions entering the cell.

Anions

Negatively charged ions exiting the cell.

Chemical Force

Ions' concentration gradient driving diffusion.

Electrical Force

Membrane potential's effect on ion movement.

Graded Potentials

Signals that modulate neuron activity.

Action Potentials

All-or-nothing signals traveling along axons.

Signal Integration

Combining multiple signals for a unified response.

Synaptic Cleft

Space for chemical communication between neurons.

Continuous Propagation

Uninterrupted nerve impulse along an axon.

Saltatory Propagation

Impulse jumps between nodes of Ranvier.

Motor Unit

A motor neuron and its muscle fibers.

Myofibril

Structure composed of repeating sarcomeres.

Sliding Filament Theory

Myosin pulls actin during muscle contraction.

Excitation-Contraction Coupling

Process linking action potential to muscle contraction.

Acetylcholine (ACh)

Neurotransmitter released at neuromuscular junction.

T Tubules

Extensions of sarcolemma transmitting action potentials.

Troponin

Protein that binds calcium, exposing actin sites.

Cross Bridge Cycle

Myosin heads attach and pull actin filaments.

Twitch Contraction

Single muscle contraction after one stimulation.

Summation

Increased force from rapid successive contractions.

Tetanus

Sustained muscle contraction without relaxation.

Proprioceptors

Sensors for body position awareness.

Golgi Tendon Organ

Monitors tension in muscles and tendons.

Muscle Spindle

Monitors muscle stretch and rate of change.

Muscle Coactivation

Simultaneous activation of agonist and antagonist muscles.

Electromyography (EMG)

Recording electrical activity of muscle tissue.