Motion Flashcards
Chapter 13 & 14
Motor system
The network of neurons and muscles that coordinate movement and control voluntary and involuntary motor functions.
Somatic motor system
The part of the motor system responsible for voluntary movements
Smooth muscle
Involuntary, non-striated muscle found in internal organs and blood vessels, controlled by the autonomic nervous system.
Striated muscle
Muscle tissue with a banded appearance, including both skeletal and cardiac muscles, involved in movement.
Cardiac muscle
A specialized striated muscle found only in the heart, responsible for pumping blood.
Skeletal muscle
Striated, voluntary muscle attached to bones that enables movement.
Flexion
A movement that decreases the angle between two body parts
Extension
A movement that increases the angle between two body parts
Muscle fibers
The individual, elongated cells that make up skeletal muscles and contain contractile elements.
Flexors
Muscles that cause flexion by contracting.
Extensors
Muscles that cause extension by contracting.
Antagonists
Muscles that oppose the action of another muscle to refine movement.
Synergists
Muscles that work together to perform the same movement.
Axial muscles
Muscles that control movements of the head
Distal muscles
Muscles that control hands
Alpha motor neurons
Neurons in the spinal cord that stimulate skeletal muscle contraction.
Motor unit
A single alpha motor neuron and all the muscle fibers it innervates.
Motor neuron pool
A group of alpha motor neurons that control a single muscle.
Slow motor unit
A motor unit with slow-twitch
Fast motor unit
A motor unit with fast-twitch fibers for quick but short-lived contractions.
Sarcomere
The basic contractile unit of muscle
Thin filaments
Actin-based filaments that interact with myosin for contraction.
Thick filaments
Myosin-based filaments that generate force for contraction.
Myosin
A motor protein in thick filaments that binds to actin and powers muscle contraction.
Actin
A structural protein in thin filaments that interacts with myosin for contraction.
Excitation–contraction coupling
The process linking electrical signals in the muscle fiber to contraction.
Sarcolemma
The specialized membrane of a muscle fiber that conducts electrical impulses.
Myofibrils
Thread-like structures within muscle fibers containing contractile proteins.
T tubules
Extensions of the sarcolemma that carry electrical signals into the muscle cell.
Muscle spindles
Sensory receptors inside muscles that detect stretching and help maintain posture.
Proprioceptors
Sensory neurons that provide feedback on body position and movement.
Proprioception
The body’s ability to sense its position and movement without visual input.
Stretch reflex
An involuntary muscle contraction triggered by stretching to maintain stability.
Gamma motor neuron
A neuron that adjusts muscle spindle sensitivity for accurate movement detection.
Golgi tendon organ
A sensory receptor in tendons that detects and regulates muscle tension.
Reciprocal inhibition
A process where activating one muscle inhibits its antagonist for smoother movement.
Central pattern generators
Neural circuits in the spinal cord that produce rhythmic movements like walking.
Definition
Answer
Lateral pathway
A descending spinal tract involved in voluntary movement
Ventromedial pathway
A spinal tract responsible for posture and balance
Corticospinal tract
A major motor pathway that originates in the motor cortex and controls voluntary movement
Motor cortex
The region of the cerebral cortex involved in planning
Pyramidal tract
Another name for the corticospinal tract
Rubrospinal tract
A motor pathway originating in the red nucleus that assists in movement control
Red nucleus
A midbrain structure involved in motor coordination
Vestibulospinal tract
A pathway that helps maintain balance and posture by coordinating head and body movements.
Tectospinal tract
A motor pathway that coordinates head and eye movements in response to visual stimuli.
Reticular formation
A network of neurons in the brainstem involved in motor control
Primary motor cortex (M1)
The main area responsible for executing voluntary movements.
Premotor area (PMA)
A motor planning area that helps coordinate movements based on external cues.
Supplementary motor area (SMA)
A region involved in planning and coordinating complex movements
Mirror neuron
A type of neuron that fires both when performing an action and when observing someone else perform the same action
Ventral lateral (VL) nucleus
A part of the thalamus that relays motor signals from the basal ganglia to the motor cortex.
Basal ganglia
A group of structures involved in movement control
Caudate nucleus
A basal ganglia component involved in motor control and learning.
Globus pallidus
A structure in the basal ganglia that regulates voluntary movement through its output to the thalamus.
Subthalamic nucleus
A part of the basal ganglia that helps modulate motor signals and movement inhibition.
Substantia nigra
A midbrain structure involved in movement and dopamine production
Striatum
The combined structure of the caudate nucleus and putamen
Parkinson’s disease
A neurodegenerative disorder caused by dopamine loss in the substantia nigra
Huntington’s disease
A genetic disorder that causes progressive degeneration of neurons in the basal ganglia
Ballism
A movement disorder characterized by rapid
Motor strip
Another term for the primary motor cortex
Population coding
A neural mechanism where groups of neurons work together to encode movement direction and force.
Cerebellum
A brain region involved in movement coordination
Ataxia
A movement disorder caused by cerebellar damage
Vermis
The central part of the cerebellum that helps control posture and axial muscle movements.
Cerebellar hemispheres
The lateral parts of the cerebellum that help coordinate voluntary limb movements.
Pontine nuclei
Brainstem structures that relay motor signals from the cortex to the cerebellum for movement planning and coordination.
