Lecture 5 - neuromotor basis Flashcards
What are the two main sections of the nervous system?
Central Nervous System (CNS): Spinal cord, brainstem, cerebellum, and cerebral region.
Peripheral Nervous System (PNS): All nervous system structures not encased in the skull or vertebral column.
What is the Neuromotor System?
Parts of the nervous system involved in the control of voluntary, coordinated movement
What are the four main components of a neuron?
Soma, Dendrites, Axon, Presynaptic terminals
What does the Soma do?
Synthesizes neurotransmitters
What is the role of dendrites?
Main input sites for the cell
What is the role of the Axon?
Sends information to other neurons, muscle cells, or glands
What do the Presynaptic Terminals do?
Transfer elements of the neuron
How do neurons communicate?
Presynaptic membranes deliver information via neurotransmitters
Postsynaptic membranes receive neurotransmitters
What is an action potential (AP)?
A rapid electrical charge transmitted along the axon.
Causes neurotransmitter release at synaptic terminals.
What is spatial and temporal summation?
Spatial summation: Multiple inputs from different synapses.
Temporal summation: Repeated input from the same synapse.
What does the Peripheral Nervous System consist of?
All nervous system structures outside the skull and vertebral column.
What are the two types of neurons in the PNS?
Afferent neurons: Carry sensory information toward the CNS.
Efferent neurons: Carry motor commands away from the CNS.
What are sensory neurons?
Afferent neurons that transmit sensory information to the CNS.
Located in muscles, skin, and joints.
Cell body in the dorsal root ganglion.
What are motor neurons?
Efferent neurons that transmit information from the CNS to muscles.
Influence movement by activating muscle contractions.
What are the two types of motor neurons?
- Alpha motor neurons: Activate skeletal muscle fibers.
- Gamma motor neurons: Regulate sensitivity of muscle spindles.
What are interneurons?
Specialized neurons that relay information between sensory and motor neurons
Important for reflexes and movement coordination
What are the five structures of the CNS involved in movement control?
- Cerebrum
- Diencephalon (Thalamus)
- Cerebellum
- Brainstem
- Spinal Cord
What are the four lobes of the cerebrum?
Frontal lobe: Initiates and controls movement.
Parietal lobe: Sensory perception.
Temporal lobe: Memory and abstract thought.
Occipital lobe: Visual perception.
What are the three motor areas in the frontal lobe?
Primary Motor Cortex: Initiates voluntary movements.
Premotor Cortex: Organizes movements before initiation.
Supplementary Motor Area: Controls sequential movements.
What is the function of the basal ganglia?
Regulates motor control by inhibiting unwanted movements.
Involved in movement initiation and force regulation.
What disease is associated with basal ganglia dysfunction?
Parkinson’s Disease.
Symptoms: Bradykinesia, akinesia, muscle rigidity, and tremors.
What is the function of the cerebellum?
Coordinates movement and postural control.
Integrates sensory information to adjust motor output.
What are the three main parts of the brainstem?
Pons: Connects cerebellum to cerebrum.
Medulla: Regulates vital physiological processes.
Reticular Formation: Integrates sensory and motor information.
What is the role of the thalamus?
Relay station for sensory and motor signals to the cerebral cortex.
What is the structure of the spinal cord?
Gray matter: Contains interneurons and unmyelinated axons.
White matter: Myelinated axons organized into tracts.
What are the two main sensory neural pathways?
Dorsal column-medial lemniscus: Fine touch, proprioception, and vibration.
Anterolateral spinothalamic tract: Crude touch, pain, and temperature.
What are the two main motor neural pathways?
Medial upper motor neuron tracts: Control posture and gross movements.
Lateral upper motor neuron tracts: Control fine motor movements.
What is a motor unit?
A lower motor neuron and all the muscle fibers it innervates.
What is the All-or-None Principle?
An action potential stimulates all muscle fibers in a motor unit.
What is Henneman’s Size Principle?
Motor neurons are recruited in order of ascending size for efficient movement control.
How does movement control progress from intent to action?
Initiation begins in the frontal lobe → Activates motor planning areas → Spinal cord → Muscle contraction.
What did Carson and Kelso (2004) demonstrate?
The same movement can activate different brain regions based on cognitive intent.
