Motor & Sensory Processes Overview

Skeletal Muscle

Muscle type attached to bones, responsible for movement

Monosynaptic Stretch Reflex

Rapid muscle contraction in response to a stretching stimulus, involving a single synapse

Feedback Control

Control of movement based on sensory feedback

PMC

Premotor Cortex involved in preparing motor sequences for action

PPC

Posterior Parietal Cortex responsible for processing sensory input regarding object location in space

Somatotopic Organisation

Organization of the motor cortex based on a map of the body

Motor Homunculus

A visual representation of the human body based on the somatotopic organization in the brain

Spinal Cord

Part of the central nervous system containing motor neurons for muscle contraction and sensory feedback circuits

Motor Cortex

Area of the brain responsible for controlling movement

Movement

The act of changing position in space

Feedforward Control

Control of movement based on predicting optimal actions from current sensory conditions and past strategies

PFC

responsible for decision-making in actions

M1

Primary Motor Cortex responsible for producing required movements

Upper Motor Neurons (UMNs)

Neurons that extend from the brain to the spinal cord, influencing lower motor neurons

Lower Motor Neurons (LMNs)

Neurons in the spinal cord that directly innervate muscles

Corticospinal Pathways

Direct pathways from the cerebral cortex to lower motor neurons, involved in voluntary movement

Corticobulbar Pathway

Pathway from the cerebral cortex to skeletal muscles of the head

Extrapyramidal Pathways

Indirect motor pathways involving rubrospinal, tectospinal, vestibulospinal, and reticulospinal tracts

Intrafusal Muscle Fibres

Muscle spindles served by sensory and motor axons, important for modifying sensitivity to stretch

Extrafusal Muscle Fibres

Muscle fibers served by alpha motor neurons, crucial for precision in muscle movement

Motor Unit

Consists of an alpha neuron and all muscle fibers it innervates, responsible for muscle contraction

Myofibrils

Bundles within muscle fibers consisting of actin and myosin filaments responsible for muscle contraction

Muscle Twitch

Single contraction-relaxation cycle of a muscle fiber in response to a single impulse

Monosynaptic Stretch Reflex (MSR)

Rapid muscle contraction in response to a stretching stimulus, involving a single synapse