Structure of the Nervous System – Vocabulary Review

A comprehensive set of vocabulary flashcards covering key anatomical terms, structures, and developmental concepts from the lecture on the nervous system.

Central nervous system (CNS)

The brain and spinal cord, encased in bone and bathed in cerebrospinal fluid.

Peripheral nervous system (PNS)

Cranial and spinal nerves plus peripheral ganglia that lie outside the CNS.

Cerebrospinal fluid (CSF)

Clear liquid that cushions, nourishes, and removes waste from brain and spinal cord.

Blood–brain dependence

Fact that the brain receives ~20 % of blood flow and cannot store energy, making it sensitive to oxygen loss.

Neuraxis

Imaginary line running the length of the CNS, used as a reference for anatomical directions.

Rostral

Toward the nose or front end (anterior) of the neuraxis.

Caudal

Toward the tail or back end (posterior) of the neuraxis.

Dorsal

Toward the back or upper surface; opposite of ventral.

Ventral

Toward the belly or lower surface; opposite of dorsal.

Ipsilateral

Located on the same side of the body.

Contralateral

Located on the opposite side of the body.

Transverse (frontal) plane

Section that cuts the brain into front and back portions.

Horizontal plane

Section that cuts the brain into upper and lower portions.

Sagittal plane

Section that cuts the brain into left and right portions.

Meninges

Three protective membranes surrounding the brain and spinal cord: dura mater, arachnoid membrane, and pia mater.

Dura mater

Tough outer meningeal layer closest to the skull.

Arachnoid membrane

Middle meningeal layer containing the CSF-filled subarachnoid space.

Pia mater

Delicate inner meningeal layer adhering to brain and spinal cord surfaces.

Subarachnoid space

Cavity between arachnoid membrane and pia mater filled with CSF.

Ventricular system

Series of interconnected cavities in the brain where CSF is produced and circulates.

Lateral ventricles

Largest pair of ventricles located in each cerebral hemisphere.

Third ventricle

Midline ventricle that separates the brain into two symmetrical halves; pierced by the massa intermedia.

Cerebral aqueduct

Narrow channel connecting the third and fourth ventricles.

Fourth ventricle

Ventricle located between the cerebellum and the brain stem.

Choroid plexus

Specialized tissue in ventricles that continuously produces CSF.

Arachnoid granulations

Protrusions into the superior sagittal sinus that reabsorb CSF into the bloodstream.

Obstructive hydrocephalus

Condition where blocked CSF flow raises intracranial pressure, risking brain damage.

Neural plate

Thickened ectodermal region that begins the development of the nervous system around day 18 of gestation.

Neural tube

Structure formed by fused neural folds; gives rise to the brain and spinal cord.

Forebrain (telencephalon)

Anterior brain division that becomes cerebral cortex, basal ganglia, and limbic system.

Diencephalon

Posterior part of the forebrain containing the thalamus and hypothalamus.

Midbrain (mesencephalon)

Middle brain division consisting of tectum and tegmentum; surrounds cerebral aqueduct.

Hindbrain

Posterior brain division made up of metencephalon (cerebellum, pons) and myelencephalon (medulla oblongata).

Sulcus (plural: sulci)

Small groove on the cerebral cortex surface.

Fissure

Large, deep groove on the cerebral cortex surface.

Gyrus (plural: gyri)

Bulge of cortical tissue between sulci or fissures.

Gray matter

Brain tissue rich in neuron cell bodies; forms the outer cerebral cortex.

White matter

Inner brain tissue composed mainly of myelinated axons beneath the cortex.

Frontal lobe

Anterior cerebral lobe involved in planning, reasoning, and movement.

Parietal lobe

Dorsal cerebral lobe processing somatosensory information and spatial orientation.

Temporal lobe

Ventral cerebral lobe important for hearing, language, and memory.

Occipital lobe

Posterior cerebral lobe devoted primarily to vision.

Basal ganglia

Subcortical nuclei involved in motor control, habit learning, and reward processing.

Limbic system

Group of interconnected structures regulating emotion, motivation, and memory.

Tectum

Dorsal part of the midbrain containing superior and inferior colliculi for visual and auditory reflexes.

Tegmentum

Ventral midbrain region housing reticular formation, red nucleus, and substantia nigra.

Cerebellum

Metencephalic structure coordinating balance, posture, and fine motor control.

Pons

Metencephalic brain-stem structure that connects cerebellum with cerebrum and regulates sleep/arousal.

Medulla oblongata

Myelencephalic structure controlling vital autonomic functions such as breathing and heart rate.

Superior sagittal sinus

Large venous channel along the brain's midline that drains blood and reabsorbed CSF.