Neuronal Pathways and Sensory Pathways

Flashcards covering key concepts, terminology, and definitions related to neuronal pathways, sensory and motor pathways, and related neurological information.

Decussation

The crossing over of neuronal pathways from one side of the central nervous system to the other.

Relay

A chain of two or three neurons transmitting impulses in neuronal pathways.

Symmetry

The pairing of neuronal pathways in a symmetrical arrangement on the left and right sides.

First-order neuron

The neuron that conducts impulses from cutaneous receptors and proprioceptors to the spinal cord or medulla.

Second-order neuron

An interneuron with its cell body in the dorsal horn of the spinal cord or medullary nuclei, extending axons to the thalamus or cerebellum.

Third-order neuron

An interneuron with cell bodies located in the thalamus, extending axons to the somatosensory cortex.

Ascending Pathways

Pathways that conduct sensory information upward through a series of neurons.

Corticospinal pathway

Also known as the pyramidal pathway, it involves upper and lower motor neurons for skilled movement.

Upper motor neurons (UMN)

Pyramidal cells located in the primary motor cortex responsible for initiating voluntary movements.

Lower motor neurons (LMN)

Ventral horn motor neurons that innervate skeletal muscles.

Extrapyramidal pathway

Polysynaptic pathways that regulate posture and balance.

Spinal tract

A bundle of axons in the central nervous system that carries specific types of information.

Sensory pathways

Neuronal pathways that transmit sensory information to the brain.

Interneuron

A neuron that transmits impulses between other neurons, particularly in the spinal cord.

Pacinian corpuscle

A type of mechanoreceptor that detects deep pressure and vibration.

Tertiary neuron

A neuron that relays information from the thalamus to the somatosensory cortex.

Nucleus gracilis

A cluster of neurons in the medulla that receives sensory input from the lower body.

Nucleus cuneatus

A cluster of neurons in the medulla that receives sensory input from the upper body.

Dorsal column

A spinal tract responsible for transmitting fine touch and proprioceptive information.

Lateral spinothalamic tract

A spinal tract that transmits pain and temperature sensations to the thalamus.

Fasciculus gracilis

A tract in the dorsal column that carries sensory information from the lower limbs.

Fasciculus cuneatus

A tract in the dorsal column that carries sensory information from the upper limbs.

Cerebellum

A structure of the brain that coordinates voluntary movements and balance.

Medial lemniscus

A central pathway that transmits touch and proprioceptive information to the thalamus.

Posterior funiculus

The section of the spinal cord that contains the dorsal columns carrying sensory information.

Neuromuscular junction

The synapse between a motor neuron and a skeletal muscle fiber where signal transmission occurs.

Pyramidal decussation

The crossing of corticospinal tract fibers in the medulla, allowing control of the opposite side of the body.

Reticular formation

A network of neurons in the brainstem involved in regulating arousal and attention.

Cerebral peduncle

A structure in the midbrain that contains bundles of axons traveling to and from the cerebrum.

Red nucleus

A nucleus in the midbrain involved in motor coordination and muscle tone.

Substantia nigra

A cluster of neurons in the midbrain that plays an important role in movement control.

Thalamus

A relay station in the brain that processes and transmits sensory information.

Motor cortex

The area of the brain responsible for planning and executing voluntary movements.

Collateral fibers

Branches of axons that extend from main axons to connect with multiple targets.

Gray commissure

The region in the spinal cord where the two sides are connected by gray matter.

White commissure

The region in the spinal cord where the two sides are connected by white matter containing myelinated axons.

Medial lemniscus

The ascending pathway in the brainstem that carries touch and proprioceptive signals to the thalamus.

Axial muscles

Muscles that support the head and trunk and are regulated by the extrapyramidal pathway.

Muscles controlling coarse limb movements

Muscles that are regulated by the extrapyramidal pathways for gross motor activities.

Lateral corticospinal tract

A major pathway for voluntary motor control located in the spinal cord.

Anterior corticospinal tract

A pathway that helps in controlling axial muscles.

Dorsal horn

The posterior part of the spinal cord that receives sensory input.

Ventral horn

The anterior part of the spinal cord that contains motor neurons.

Spinal cord

The central structure that transmits signals between the brain and the rest of the body.

Mediating movement

The process by which the nervous system integrates and coordinates physical actions.

Somatosensory cortex

The area of the cerebral cortex that processes sensory input from the body.

Pain pathway

The neural pathway that transmits pain sensations from the periphery to the brain.

Temperature pathway

The neural pathway that transmits temperature sensations to the brain.

Afferent fibers

Nerve fibers that carry sensory information towards the central nervous system.

Efferent fibers

Nerve fibers that carry motor signals away from the central nervous system.

Sensory receptors

Specialized cells that detect environmental stimuli and convert them into neural signals.

Proprioceptors

Receptors that sense body position and movement.

Impulses

Electrical signals that are transmitted by neurons.

Travel upwards

The direction of the sensory pathways leading to the brain.

Complex pathways

Multiple interconnected tracts involved in motor and sensory functions.

Chain of neurons

A sequence of interconnected neurons involved in transmitting signals.

Neuronal pathways

Routes through which signals are transmitted in the nervous system.

Skilled movements

Fine, coordinated movements generated by the central nervous system.

Brain stem

The portion of the brain connecting the brain to the spinal cord, controlling many basic life functions.

Intermodal pathways

Pathways that integrate various types of sensory information.

Functional pathways

Neuronal pathways dedicated to specific functions within the nervous system.

All motor pathways

Includes all pathways involved in the control of muscular movements.

Cerebral hemisphere

The two halves of the brain that are involved in higher cognitive functions.

Nervous system integration

The process by which the nervous system coordinates and processes information.

Reflex pathways

Neural pathways that mediate automatic responses to stimuli.

Neurotransmitters

Chemical messengers that transmit signals across synapses between neurons.

Synapse

The junction between two neurons where signal transmission occurs.

Motor control

The regulation of muscle movements including the initiation and coordination of movements.

Dendrites

Branching extensions of a neuron that receive signals from other neurons.

Axon

The long, threadlike part of a neuron along which impulses are conducted.

Myelinated axons

Axons covered with a myelin sheath, which increases the speed of nerve impulses.

Sensory integration

The process by which the brain processes and interprets sensory information.

Locomotion

The ability to move from one place to another, often involving coordinated muscle activity.

Muscle tone

The continuous partial contraction of the muscles that helps maintain posture.

Visual field

The area in which objects can be seen by the eyes at any given moment.

Reticular activating system

A network in the brain that affects wakefulness and attention.

Corticobulbar tract

A motor pathway connecting the brain to cranial nerves responsible for facial and neck movements.

Voluntary control

Conscious regulation of muscle movements.

Involuntary control

Automatic regulation of muscle movements.

Neural circuits

Interconnected networks of neurons that work together to perform specific functions.

Anterior horn

The part of the spinal cord that contains the cell bodies of motor neurons.

Posterior horn

The area of the spinal cord where sensory neurons enter.

Peripheral nervous system

The part of the nervous system outside the brain and spinal cord.

Central nervous system

The brain and spinal cord, responsible for processing and integrating information.

Neural development

The process through which the nervous system forms and matures.

Neuroplasticity

The ability of the nervous system to change and adapt in response to experience.

Somatic nervous system

The part of the peripheral nervous system that controls voluntary movements.

Autonomic nervous system

The part of the peripheral nervous system that controls involuntary functions.

Neuroscience

The study of the anatomy and physiology of the nervous system.

Neurological disorders

Conditions that affect the nervous system, leading to various functional impairments.

Electrophysiology

The study of the electrical properties of biological cells and tissues.

Neuroanatomy

The study of the structure of the nervous system.

Functional MRI

A type of brain scan used to measure and map brain activity.

CT scan

A diagnostic imaging technique used to create detailed images of internal organs.

EEG

A test that detects electrical activity in the brain using small electrodes.

Neuroimaging

Techniques used to visualize the structure and function of the brain.

Clinical neurophysiology

The study of the electrical activity of the nervous system for diagnosing neurological conditions.

Spinal reflexes

Automatic responses to stimuli that involve a direct pathway through the spinal cord.

Neuroethology

The study of the neural basis of natural animal behavior.

Gabapentin

A medication used to treat neuropathic pain and seizures.