Module 5: Structure of the Nervous System & Neuroanatomy

Comprehensive vocabulary flashcards covering neuroanatomy, brain imaging techniques, anatomical planes and axes, gross brain and spinal cord organization, meninges, ventricles, and neurobiology of sex differentiation from Module 5.

Computed Tomography (CT)

A structural brain imaging method developed by Hounsfield and Cormack (1979 Nobel Prize) that uses X-ray beams to generate data for a digitally reconstructed brain slice image based on tissue density; ideal for rapid structural screening of trauma and intracranial hemorrhage.

Magnetic Resonance Imaging (MRI)

A high-detail structural imaging technique that maps computer signals based on how hydrogen atoms in the brain respond to perturbations of a strong magnetic field, without requiring X-irradiation and capable of imaging brain slices at any angle.

CLARITY

An imaging method that renders intact post-mortem brain tissue optically transparent by replacing tissue lipids with a hydrogel polymer, enabling deep 3D visualization of cellular networks and neuronal circuits without sectioning.

Functional Brain Imaging

Techniques that detect which brain regions exhibit the highest activity during a specific function by tracking regional blood flow and metabolic shifts driven by active neurons demanding more glucose and oxygen.

Positron Emission Tomography (PET)

A functional imaging technique that measures changes in regional blood flow and metabolism by tracking the uptake of a radioactive 2-DG probe by metabolically active neurons.

Functional MRI (fMRI)

A functional neuroimaging method that measures active brain regions via blood-oxygen-level-dependent (BOLD) contrast by detecting the ratio of oxyhemoglobin to deoxyhemoglobin without requiring radioactive tracers.

GCaMP Tracing

A cellular/molecular functional imaging technique that genetically expresses fluorescent sensors that illuminate upon calcium influx, which triggers synaptic transmission during neuronal activity.

Rostral / Anterior

Anatomical directional term indicating a location toward the front of the body or brain.

Caudal / Posterior

Anatomical directional term indicating a location toward the back of the body or brain.

Dorsal

Anatomical directional term pertaining to the top of the brain or the back side of the body.

Ventral

Anatomical directional term indicating a position pointing toward the belly side of the body or the bottom of the brain.

Midline

The imaginary symmetrical line that divides the body or brain into equal left and right halves.

Medial

Anatomical directional term meaning toward the midline of the body or brain.

Lateral

Anatomical directional term meaning situated away from the midline of the body or brain.

Ipsilateral

Anatomical term referring to structures located on the same side of the body as another reference structure.

Contralateral

Anatomical term referring to structures located on the opposite side of the body relative to another structure.

Sagittal Plane

A vertical anatomical plane that divides the body or brain into right and left sections.

Midsagittal Plane

A specific vertical plane passing directly through the midline that divides the body or brain into equal left and right halves.

Coronal Plane

A vertical anatomical plane that divides the brain or body into anterior (front) and posterior (back) sections.

Horizontal (Transverse) Plane

An anatomical plane that divides the brain or body into superior (top) and inferior (bottom) sections.

Cerebrum

The largest part of the brain; handles sensory information, motor processing, attention, perception, and higher cognitive functions.

Cerebellum

A large hindbrain structure situated near the pons that coordinates movement, balance, and fine motor skills.

Brain Stem

The stalk-like division of the brain composed of the midbrain, pons, and medulla oblongata that controls vital autonomic functions such as breathing, consciousness, and body temperature.

Medulla Oblongata

The inferior segment of the brain stem directly continuous with the spinal cord; regulates essential autonomic functions.

Thalamus

A forebrain sensory relay station known as the 'gateway to the cerebral cortex' that processes and routes sensory information to neocortical regions.

Hypothalamus

A forebrain region that regulates homeostatic functions, controls body temperature, and secretes hormones via endocrine pathways.

Hippocampus

A limbic structure situated in the temporal lobe that is crucial for memory formation, consolidation, and learning.

Amygdala

A subcortical almond-shaped structure that plays a critical role in processing fear, emotional responses, and emotional memories.

Basal Ganglia

A group of subcortical nuclei located deep within the cerebral hemispheres that control movement initiation and voluntary motor patterns.

Corpus Callosum

A thick, broad band of commissural nerve fibers that physically and functionally bridges the left and right cerebral hemispheres.

Sulcus

A groove or furrow on the cerebral surface that increases the total surface area of the neocortex.

Gyrus

An elevated ridge or bump on the folded surface of the cerebral neocortex.

Frontal Lobe

The anterior lobe of the cerebral cortex involved in voluntary motor control, speech production (Broca's area), and executive functions.

Parietal Lobe

The cerebral lobe situated posterior to the central sulcus that processes somatosensory and somatic information.

Temporal Lobe

The ventrolateral cerebral lobe involved in auditory perception, memory, and speech comprehension (Wernicke's area).

Occipital Lobe

The most posterior lobe of the cerebral cortex containing the primary visual cortex (Area 17) for visual sensory processing.

Brodmann's Areas

A cytoarchitectural map of the cerebral cortex dividing the neocortex into numbered anatomical regions based on cellular layer organization and functional specialization.

Area 4 (Motor Cortex)

The Brodmann area corresponding to the primary motor cortex in the frontal lobe responsible for executing voluntary movements.

Area 17 (Visual Cortex)

The Brodmann area in the occipital lobe corresponding to the primary visual cortex responsible for processing visual stimuli.

Area 45 (Broca's Area)

The Brodmann area located within the frontal lobe that controls the motor execution of speech production.

Area 22 (Wernicke's Area)

The Brodmann area located within the temporal lobe responsible for the comprehension and understanding of written and spoken language.

Spinal Cord

A cylindrical bundle of nervous tissue attached to the brain stem forming part of the central nervous system; conducts sensory and motor impulses to and from the brain.

Dorsal Root

The posterior branch of a spinal nerve extending into the spinal cord grey matter that carries incoming sensory neuron signals into the CNS.

Ventral Root

The anterior basal branch of each spinal nerve carrying motor neuron axons away from the spinal cord to target muscles and tissues.

Peripheral Nervous System (PNS)

The division of the nervous system consisting of all cranial and spinal nerves and ganglia situated outside the brain and spinal cord.

Somatic PNS

The component of the peripheral nervous system consisting of spinal nerves that innervate the skin, joints, and skeletal muscles under voluntary motor control.

Visceral PNS (Autonomic Nervous System)

The involuntary division of the peripheral nervous system that innervates internal organs, blood vessels, and glands.

Afferent

Descriptive term for neural pathways or nerve fibers conveying impulses toward a central reference point, such as sensory fibers carrying data into the CNS.

Efferent

Descriptive term for neural pathways or nerve fibers conveying impulses away from a central reference point, such as motor axons carrying commands away from the CNS.

Cranial Nerves

The 12 pairs of peripheral nerves that arise directly from the brain and brain stem, innervating primarily structures of the head and neck.

Meninges

The three connective tissue membranes (dura mater, arachnoid membrane, and pia mater) that encapsulate and protect the brain and spinal cord.

Dura Mater

The tough, inelastic, outermost protective fibrous membrane layer of the meninges.

Arachnoid Membrane

The middle web-like meningeal membrane layer located between the dura mater and the pia mater.

Pia Mater

The thin, vascular innermost membrane of the meninges that adheres directly to the convolutions of the brain and spinal cord surface.

Blood-Brain Barrier

A protective physiological barrier of specialized brain capillaries that shields neural activity from sudden fluctuations in systemic blood composition.

Meningitis

A clinical inflammatory condition affecting the meningeal membranes surrounding the brain and spinal cord.

Ventricles

A system of fluid-filled caverns and canals within the brain, including the lateral ventricles, third ventricle, cerebral aqueduct, and fourth ventricle.

Choroid Plexus

A specialized network of vascular ependymal tissue located within the brain ventricles that secretes cerebrospinal fluid (CSF).

Cerebrospinal Fluid (CSF)

The clear liquid that fills brain ventricles and the subarachnoid space; acts as a shock absorber in which the central nervous system floats to cushion mechanical impact.

Hydrocephalus

A condition characterized by impaired CSF drainage or excess fluid buildup in the ventricular system, exerting elevated pressure on brain tissue and the skull.

Neocortex

The phylogenetically newer 6-layered cerebral cortex unique to mammals, featuring cell bodies arranged in sheets and at least one layer of pyramidal output cells.

Biological Sex

The biological differentiation between males and females established through chromosomal, gonadal, and hormonal factors.

Gender

Socially constructed characteristics, roles, expectations, and identities associated with men and women.

Sex Determination

The initial genetic and developmental event that directs an undifferentiated embryo to develop along a male or female pathway.

Sexual Differentiation

The progressive developmental cascade by which an individual acquires male- or female-typical morphological, neural, and behavioral traits.

Gender Role

Culturally defined behaviors and attitudes deemed appropriate for a specific sex, learned early in life and shaped by environmental influences.

Organizational Effects

Permanent structural and functional changes in neural architecture and behavior caused by sex steroid hormones acting during early, developmentally defined critical periods.

SDN-POA (Sexually Dimorphic Nucleus of the Preoptic Area)

A hypothalamic nucleus involved in sexual and motivated behaviors whose volume is permanently enlarged and masculinized by exposure to testosterone during an early critical window.

Aromatase

The synthesizing enzyme that converts androgens (such as testosterone) into estrogens (such as estradiol).