General Principles and Overview of Neuroanatomy

Comprehensive vocabulary flashcards covering basic anatomical terminology, brain cuts/sections, divisions of the nervous system, brain and spinal cord structures, cell types, staining techniques, and neuroglial functions.

Medial

Toward the middle of the body or a structure.

Lateral

Toward the side of the body or a structure.

Superior

Located above another structure.

Inferior

Located below another structure.

Ipsilateral

Located on or pertaining to the same side of the body.

Contralateral

Located on or pertaining to the opposite side of the body.

Anterior

Toward the head end or front of the body.

Posterior

Toward the tail end or back of the body.

Proximal

Located near the center of the body or point of origin.

Distal

Located toward the periphery or away from the point of origin.

Dorsal

Toward the back of the body.

Ventral

Toward the belly or stomach.

Afferent

Carrying neural impulses into a region of interest (sensory).

Efferent

Carrying neural impulses away from a region of interest (motor).

Coronal Section

A brain section plane that separates the brain from front to back, often resembling a butterfly in cross-section.

Sagittal Section

A brain section plane that slices down the midline to allow observation of structures on each half.

Horizontal Section

A brain section plane that separates the brain from top to bottom.

Nucleus (Neuroanatomy)

A collection or group of nerve cell bodies located within the Central Nervous System (CNS).

Ganglion

A collection or group of nerve cell bodies located within the Peripheral Nervous System (PNS).

Tract

A bundle of axons located within the Central Nervous System (CNS).

Nerve

A bundle of axons located within the Peripheral Nervous System (PNS).

White Matter

Nervous tissue composed of axon bundles that appears white due to covering myelin sheaths.

Gray Matter

Nervous tissue composed of clusters of cell bodies, exhibiting a dark gray appearance.

Somatic Nervous System

A division of the peripheral nervous system providing voluntary sensory and motor innervation to all body parts except viscera, smooth muscle, and glands.

Autonomic Nervous System

The involuntary division of the peripheral nervous system regulating smooth muscle, cardiac muscle, and glands via parasympathetic and sympathetic divisions.

Sympathetic Nervous System

The division of the autonomic nervous system originating in the thoracolumbar region ($T_1$–$L_2$) that prepares the body for action ('fight or flight') using norepinephrine.

Parasympathetic Nervous System

The division of the autonomic nervous system originating in the craniosacral region (CN III, VII, IX, X, $S_2$–$S_4$) that helps the body relax and recuperate ('rest and digest') using acetylcholine.

Cranial Nerves

12 pairs of peripheral nerves numbered by how they emerge from front to back, with 10 pairs arising from the brainstem and 2 pairs (CN I and CN II) arising from the forebrain.

Spinal Nerves

31 pairs of peripheral nerves associated with the spinal cord, consisting of 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal pair.

Spinal Cord

A tubular structure housed within the vertebrae and covered by meninges that carries sensory information to the brain and motor commands to muscles and organs.

Gyrus

A raised ridge on the grooved outer layer (cortex) of the brain.

Sulcus

A groove or furrow on the outer layer (cortex) of the brain.

Thalamus

A diencephalic structure located inferior to the lateral ventricles that receives sensory information from all senses except olfaction and relays it to the cortex.

Hypothalamus

A diencephalic structure located inferior to the thalamus that controls emotions and motivated behaviors such as eating and drinking.

Pineal Gland

An epithalamic structure that secretes melatonin and regulates daily biological rhythms in the body.

Basal Ganglia

A group of brain structures including the caudate nucleus, putamen, globus pallidus, subthalamic nucleus, and substantia nigra involved in motor control and initiating movements.

Limbic System

A functional brain network including the cingulate gyrus, hippocampus, amygdala, fornix, and mammillary bodies responsible for emotional regulation and learning.

Reticular Formation

A brainstem structure involved in regulating sleep, arousal, body temperature, and motor control.

Periaqueductal Gray (PAG)

A midbrain region primarily responsible for pain perception.

Superior Colliculi

Paired sensory structures in the midbrain responsible for visual processing.

Inferior Colliculi

Paired sensory structures in the midbrain responsible for auditory processing.

Pons

A brainstem region containing motor and sensory nuclei that innervate the face.

Medulla

The lowermost part of the brainstem marking the transition from brain to spinal cord, regulating vital functions like heart rate and breathing.

Cerebellum

A brain structure involved in motor coordination and learning.

Meninges

The three protective membrane wrappings of the central nervous system, consisting of the dura mater, arachnoid mater, and pia mater.

Dura Mater

The tough, outermost layer of the meninges.

Arachnoid Mater

The spiderweb-like middle layer of the meninges, containing the CSF-filled subarachnoid space beneath it.

Pia Mater

The soft, delicate innermost layer of the meninges that adheres directly to the surface of the brain and spinal cord.

Blood-Brain Barrier

A protective layer of endothelial cells that limits the passage of substances between the blood and brain tissue.

Cerebral Ventricles

Fluid-filled cavities within the brain (lateral, third, and fourth ventricles) that produce and circulate cerebrospinal fluid (CSF).

Input Zone (Neuron)

The functional zone of a neuron consisting of dendrites and soma where information is collected and processed from the environment or other cells.

Integration Zone (Neuron)

The functional zone of a neuron (typically the axon hillock) where the decision to produce a neural signal is made.

Conduction Zone (Neuron)

The functional zone of a neuron comprising the axon, where electrical signals are transmitted over short or long distances.

Output Zone (Neuron)

The functional zone of a neuron consisting of axon terminals, where information is transferred across synapses to other cells.

Multipolar Neuron

An anatomical type of neuron characterized by many dendrites extending from the cell body and a single axon.

Bipolar Neuron

An anatomical type of neuron with a single dendrite extending from the cell body and a single axon, usually sensory.

Unipolar Neuron

An anatomical type of neuron with a single branch extending in two directions from the cell body, serving as both dendrite and axon.

Nissl Stain

A histological staining technique that selectively outlines all neuron cell bodies in tissue.

Golgi Stain

A histological staining technique that completely fills and visualizes the detailed structure of a small fraction of whole neurons.

Astrocytes

Star-shaped CNS glia that maintain the blood-brain barrier, provide structural support, regulate ion and nutrient concentrations, recycle neurotransmitters, and form scar tissue after injury.

Oligodendrocytes

Glial cells in the central nervous system (CNS) responsible for forming myelin sheaths around CNS axons and providing structural framework.

Microglia

Phagocytic glial cells in the CNS that remove cell debris, wastes, and pathogens.

Ependymal Cells

CNS glial cells lining ventricles and the central canal that assist in producing, circulating, and monitoring cerebrospinal fluid.

Schwann Cells

Glial cells in the peripheral nervous system (PNS) responsible for myelination of peripheral axons and aiding repair after injury.

Satellite Cells

PNS glial cells that surround neuron cell bodies in ganglia, regulating $O_2$, $CO_2$, nutrient, and neurotransmitter levels.

Nodes of Ranvier

Unmyelinated gaps along an axon between adjacent myelin segments containing high densities of $Na^+$ and $K^+$ channels where action potentials are regenerated.