Anatomical Orientations and Divisions of the Human Nervous System

A complete vocabulary set covering anatomical orientations, divisions of the nervous system, tissue types, spinal cord regions, and neural pathways based on lecture notes.

Peripheral Nervous System (PNS)

Division of the nervous system consisting of cranial nerves and spinal nerves that mediates signals coming in and out of the Central Nervous System (CNS).

Central Nervous System (CNS)

Division of the nervous system consisting of the cerebral hemispheres, diencephalon, cerebellum, brainstem, and spinal cord that operates to analyze and integrate sensory and motor information.

Rostral

Anatomical directional term meaning toward the nose.

Caudal

Anatomical directional term meaning toward the tail.

Dorsal

Anatomical directional term meaning towards the back.

Ventral

Anatomical directional term meaning towards the belly.

Medial

Anatomical directional term meaning towards the midline.

Lateral

Anatomical directional term meaning away from the midline.

Cerebral Cortex

A thin sheet of grey matter that envelops the entire brain.

White Matter

Collection of axons that appears white due to myelin.

Gray Matter

Cell bodies grouped into structures called cortex or nuclei.

Cortex

Layered structure of gray matter on the outside of the brain.

Nuclei

Subcortical collection of cell bodies.

Nerves

Bundles of axons in the Peripheral Nervous System (PNS) ensheathed by nested layers of connective tissue that segregate and compartmentalize axons from one another.

Afferent Nerves

Nerves entering the Central Nervous System (CNS) that carry ascending sensory information.

Efferent Nerves

Nerves exiting the Central Nervous System (CNS) that carry descending motor information.

Somatic Control

Voluntary motor control, such as coming to class or raising your hand.

Visceral Control

Involuntary control, governing functions like heart rate, digestion, and respiration (with caveats).

Somatic Motor System

Motor system consisting of motor nerves that project to skeletal muscle used during voluntary actions.

Visceral Motor System

Involuntary motor system comprising sympathetic, parasympathetic, and enteric divisions, autonomic ganglia, and associated nerves projecting to smooth muscles, cardiac muscles, and glands.

Nerve Roots

The origination points of the spinal nerves, serving as the principal PNS structure linking body components with the CNS.

Dorsal Horn

Gray matter region of the spinal cord associated with touch, proprioception, noxious (harmful) stimuli, temperature, and visceral sensations.

Ventral Horn

Gray matter region of the spinal cord containing motor neurons that project out of the cord.

Gracile Fasciculus

Afferent sensory tract in the dorsal columns responsible for sensation of the lower limbs.

Cuneate Fasciculus

Afferent sensory tract in the dorsal columns responsible for sensation of the upper limbs.

Spinocerebellar Tracts

Afferent sensory tracts responsible for balance and coordination, monitoring/protection of active movement, 3D body position, and proprioception for smooth motor movements.

Spinothalamic Tracts

Afferent sensory tracts responsible for carrying noxious (harmful) and thermal stimuli.

Lateral Corticospinal Tract

Efferent motor tract starting in the cortex and stopping in the spinal cord that controls fine motor movements below the neck.

Rubrospinal Tract

Efferent motor tract responsible for the regulation of muscle tone of upper limbs and feedback.

Vestibulospinal Tract

Efferent motor tract related to balance, especially during reflexive head movement.

Anterior Reticulospinal Tract

Efferent motor tract responsible for posture during standing and walking.

Tectospinal Tract

Efferent motor tract responsible for reflexive orienting head and neck movements.

Anterior Corticospinal Tract

Efferent motor tract responsible for the control of trunk muscles and posture.