Organization of the Central Nervous System Part 2

Vocabulary-style practice flashcards generated from the neurology lecture covering the spinal cord, peripheral nerves, autonomic nervous system, meninges, and ventricular system.

Central Gray Area

The central section of the spinal cord cross-section composed of unmyelinated nerve fibers and cell bodies.

Surrounding White Area

The region of the spinal cord surrounding the central gray area, consisting of closely packed myelinated fibers.

Gray Commissure

The bridge of gray matter that links the two wings of the butterfly shape in the spinal cord.

Dorsal (Posterior) Horn

The sensory region of the spinal cord gray matter.

Ventral (Anterior) Horn

The motor region of the spinal cord gray matter.

Spinal Ganglion

A mass of nerve cell bodies appearing as an ovoid swelling on each dorsal root near or inside each intervertebral foramen.

Rami (Ramus)

Small branchlike structures extending from a longer structure or dividing into two or more parts.

Anterior Root

Bundles of efferent (motor) nerve fibers that transmit impulses away from the spinal cord, originating from anterior horn motor nuclei.

Final Common Pathway

A concept described by Charles Sherrington referring to motor nerves after impulses leave the neuraxis, serving as the terminal route for all impulses acting on muscle.

Posterior Root

Bundles of afferent (sensory) nerve fibers that transmit touch, pain, temperature, and vibration impulses toward the central nervous system.

Posterior Root Ganglion

A swelling on the posterior root of a spinal nerve that contains sensory nerve cell bodies.

Mixed Nerves

Nerves formed by the union of anterior and posterior roots carrying both sensory and motor impulses.

Vertebrae and Spinal Nerves Distribution

The axial system consisting of 7 cervical vertebrae (8 pairs of cervical nerves), 12 thoracic vertebrae (12 pairs of thoracic nerves), 5 lumbar vertebrae (5 pairs of lumbar nerves), 1 sacrum (5 pairs of sacral nerves), and 1 coccyx (1 pair of coccygeal nerves).

Dorsal Ramus

A branch of a spinal nerve that supplies the muscles and skin of the back.

Ventral Ramus

A branch of a spinal nerve; the first four cervical ventral rami supply front neck muscles and skin, while the lower cervical and upper thoracic ventral rami form the brachial plexus.

Cervical Plexus

A nerve network formed by the ventral rami of the first four cervical nerves (C1–C4) and the upper part of C5.

C1 Spinal Nerve

Cervical nerve root controlling the carotid plexus to determine blood pressure, manage head blood supply, and cause headaches.

Brachial Plexus

A network formed by the ventral rami of the lower half of C4, C5–C8, T1, and the upper half of T2.

Enteric Division

A component of the autonomic nervous system formed by neuronal plexuses within the gastrointestinal (GI) tract.

Sympathetic Division

The body's alerting division within the autonomic nervous system responsible for the fight-or-flight response.

Parasympathetic Division

A division of the autonomic nervous system that produces a calming effect on the body.

Endocrine System

A network of glands and structures that release hormones into the circulatory system, influencing metabolism, pancreas, pineal gland, pituitary gland, gonads, thyroid, and adrenal glands.

Dura Mater

A two-layered protective membrane and lining for the cranial vault consisting of an outer periosteal layer and an inner meningeal layer.

Falx Cerebri

A major fold of the dura mater's meningeal layer situated in the longitudinal fissure separating the two cerebral hemispheres.

Tentorium Cerebelli

A fold of the meningeal layer of dura mater that separates the cerebellum and brainstem from the occipital lobes.

Falx Cerebelli

An infolding of the meningeal layer of dura mater that partially separates the two cerebellar hemispheres.

Diaphragma Sella

A fold of dura mater that covers the sella turcica ('Turkish Chair') of the sphenoid bone, which holds the pituitary gland.

Arachnoid Membrane

A delicate web of reticular connecting fibers lined with mesothelium that projects into venous sinuses to form arachnoid villi and granulations.

Subarachnoid Space

The tissue space located beneath the arachnoid membrane that is filled with cerebrospinal fluid.

Pia Mater

The highly vascular, deepest meningeal layer responsible for the pink color of the brain; projects into the ventricles to form the choroid plexus.

Lateral Ventricles

Paired, C-shaped cavities located in each cerebral hemisphere (parietal lobe, extending into frontal, occipital, and temporal lobes) that connect to the 3rd ventricle via the Foramen of Monro.

Foramen of Monro

The interventricular foramen that connects each lateral ventricle to the 3rd ventricle.

3rd Ventricle

A small slit cavity located between the thalami that connects to the 4th ventricle via the Cerebral Aqueduct (Aqueduct of Sylvius).

Aqueduct of Sylvius

The cerebral aqueduct connecting the 3rd ventricle to the 4th ventricle.

4th Ventricle

A ventricular cavity situated anterior to the cerebellum and posterior to the pons and upper half of the medulla.

Choroid Plexus

Structures formed by the pia mater within the ventricles that serve as the major site of cerebrospinal fluid formation.

Cerebrospinal Fluid (CSF)

Fluid that cushions the CNS against bone, regulates intracranial pressure, protects from trauma, provides nourishment, and removes waste.

CSF Flow Pathway

The path of cerebrospinal fluid traveling from the lateral ventricles to the 3rd ventricle, through the 4th ventricle, into the subarachnoid space, and surrounding the cerebrum and spinal cord.

Falx Cerebri

A major fold of the dura mater located within the longitudinal cerebral fissure that separates the left and right cerebral hemispheres.

Tentorium Cerebelli

A fold of the dura mater located in the transverse fissure that separates the occipital lobes of the cerebrum from the underlying cerebellum.

Foramen of Monro (Interventricular Foramen)

The passage that connects each lateral ventricle to the central third ventricle within the ventricular system.

Choroid Plexus

A specialized vascular structure formed by the pia mater within the brain ventricles that serves as the primary site of cerebrospinal fluid (CSF) production.

Final Common Pathway

A concept introduced by Charles Sherrington describing alpha motor neurons (anterior horn cells) as the ultimate pathway for all neural impulses producing muscle movement.

Central Sulcus (Fissure of Rolando)

The prominent vertical groove on the cerebral cortex that separates the frontal lobe from the parietal lobe.

Lateral Sulcus (Sulcus of Sylvius)

The horizontal groove separating the frontal and parietal lobes superiorly from the temporal lobe inferiorly.

Agnosia

A term coined by Sigmund Freud in 1891 to describe clinical disorders characterized by impaired cortical sensory recognition.

Central Gray Area

The H-shaped central section of the spinal cord cross-section composed primarily of unmyelinated nerve fibers and neuronal cell bodies.

Surrounding White Area

The outer region of the spinal cord cross-section surrounding the central gray matter, consisting of closely packed myelinated nerve fibers.

Gray Commissure

The transverse bridge of gray matter that links the two lateral wings of the spinal cord gray matter.

Dorsal Horn

The posterior region of the spinal cord gray matter that receives sensory (afferent) neural input.

Ventral Horn

The anterior region of the spinal cord gray matter containing motor nuclei that send efferent impulses to muscles.

Spinal Ganglion

An ovoid mass of nerve cell bodies situated on each dorsal root near or within the intervertebral foramen.

Ramus

A small branchlike structure extending from a larger nerve structure or dividing into multiple sub-branches.

Anterior Root

Bundles of efferent motor nerve fibers originating from anterior horn motor nuclei that transmit impulses away from the spinal cord.

Final Common Pathway

Charles Sherrington's concept referring to motor neurons after impulses leave the neuraxis, serving as the ultimate route for all impulses acting on muscle.

Posterior Root

Bundles of afferent sensory nerve fibers transmitting sensations of touch, pain, temperature, and vibration toward the central nervous system.

Posterior Root Ganglion

A localized swelling on the posterior root of a spinal nerve containing sensory nerve cell bodies.

Mixed Nerves

Nerves formed by the convergence of anterior and posterior roots that carry both sensory and motor impulses.

Vertebrae and Spinal Nerves Distribution

The axial division consisting of 7 cervical vertebrae (8 nerve pairs), 12 thoracic vertebrae (12 nerve pairs), 5 lumbar vertebrae (5 nerve pairs), 1 sacrum (5 nerve pairs), and 1 coccyx (1 nerve pair).

Dorsal Ramus

A branch of a spinal nerve that supplies neural innervation to the muscles and skin of the back.

Ventral Ramus

A branch of a spinal nerve that supplies front neck muscles and skin in upper levels, and forms major nerve networks in lower levels.

Cervical Plexus

A nerve network formed by the ventral rami of C1 through C4 and the upper part of C5.

C1 Spinal Nerve

The first cervical nerve root that controls the carotid plexus to regulate blood pressure, manage head blood supply, and trigger headaches.

Brachial Plexus

A network formed by the ventral rami of the lower half of C4, C5 through C8, T1, and the upper half of T2.

Enteric Division

A component of the autonomic nervous system formed by intrinsic neuronal plexuses within the gastrointestinal tract.

Sympathetic Division

The alerting branch of the autonomic nervous system responsible for triggering fight-or-flight responses.

Parasympathetic Division

The branch of the autonomic nervous system that exerts a calming effect on bodily functions.

Endocrine System

A network of glands that secrete hormones directly into the bloodstream to regulate metabolism and major organ functions.

Dura Mater

A tough, two-layered outer membrane protecting the cranial vault, comprising periosteal and meningeal layers.

Falx Cerebri

A major fold of the dural meningeal layer located in the longitudinal fissure separating the two cerebral hemispheres.

Tentorium Cerebelli

A dural fold located in the transverse fissure separating the occipital lobes of the cerebrum from the underlying cerebellum.

Falx Cerebelli

An infolding of the meningeal dura mater that partially separates the two cerebellar hemispheres.

Diaphragma Sella

A dural fold that covers the sella turcica of the sphenoid bone, encasing the pituitary gland.

Arachnoid Membrane

A delicate, web-like avascular middle meningeal layer composed of reticular fibers lined with mesothelium.

Subarachnoid Space

The fluid-filled space beneath the arachnoid membrane containing cerebrospinal fluid and major blood vessels.

Pia Mater

The highly vascular, innermost meningeal layer adhering directly to the surface of the brain and spinal cord.

Lateral Ventricles

Paired C-shaped cavities within the cerebral hemispheres that communicate with the third ventricle via the interventricular foramina.

Foramen of Monro

The interventricular passage connecting each lateral ventricle to the central third ventricle.

3rd Ventricle

A narrow slit-like cavity located between the left and right thalami.

Aqueduct of Sylvius

The narrow cerebral aqueduct connecting the third ventricle to the fourth ventricle.

4th Ventricle

A diamond-shaped ventricular cavity located anterior to the cerebellum and posterior to the pons and upper medulla.

Choroid Plexus

A vascular network of pia mater covered by ependymal cells within the ventricles that produces cerebrospinal fluid.

Cerebrospinal Fluid (CSF)

A clear fluid that cushions the central nervous system against physical shock, regulates intracranial pressure, provides nourishment, and removes metabolic waste.

CSF Flow Pathway

The circulation path of fluid traveling from the lateral ventricles, through the third and fourth ventricles, into the subarachnoid space surrounding the brain and spinal cord.

Central Sulcus

The prominent cortical groove, also known as the Fissure of Rolando, that separates the frontal lobe from the parietal lobe.

Lateral Sulcus

The horizontal groove, also known as the Sulcus of Sylvius, that separates the frontal and parietal lobes from the temporal lobe.

Agnosia

A term coined by Sigmund Freud in 1891 describing clinical conditions where cortical sensory recognition is impaired.

Peripheral Nervous System Components

The structural division consisting of cranial nerves, spinal/peripheral nerves, and peripheral parts of the autonomic nervous system.

Ascending Tracts

Bundles of axons in the spinal cord white matter that carry sensory information upward toward the brain.

Descending Tracts

Bundles of axons in the spinal cord white matter that carry motor commands downward from the brain to motor neurons.

C2 Spinal Nerve Control

The cervical nerve root responsible for innervating the eyes, ears, and paranasal sinuses.

C3 Spinal Nerve Control

The cervical nerve root responsible for innervating structures of the face and teeth.

C4 Spinal Nerve Control

Cervical spinal nerve root that provides neural control to the pharynx and larynx.

C5 Spinal Nerve Control

Cervical spinal nerve root that provides neural control to the neck and throat.

T1 Spinal Nerve Control

Thoracic spinal nerve root that supplies innervation to the trachea, esophagus, and esophageal sphincter.

Epineurium Formation

The outer sheath of peripheral nerves created when the dura mater extends outward along cranial and spinal nerves.

Arachnoid Villi

Projections of the middle meningeal layer into venous sinuses that aggregate into granulations for reabsorbing fluid.

Thalamus

A paired central brain structure resting on the brainstem that acts as a switchboard and relay station between subcortical structures and the cerebral cortex.

High CSF Pressure Diagnostic Indicators

Elevated pressure measured via lumbar puncture indicating conditions such as intracranial tumor, hemorrhage, hydrocephalus, meningitis, or encephalitis.