Central and Peripheral Nervous System Anatomy

Vocabulary flashcards covering the central nervous system, brain structures, functional centers, spinal nerves, and cerebrospinal fluid based on the anatomy lecture notes.

Somatic Nervous System (SNS)

A division of the Peripheral Nervous System that integrates control over skeletal muscle.

Autonomic Nervous System (ANS)

A division of the Peripheral Nervous System that automatically regulates vital internal organs and systems.

Frontal Lobe

The largest and most complex of the 5 cerebral lobes, encased within the frontal bone, concerned with higher intellectual functions, behavioral aspects, and housing the primary motor cortex.

Parietal Lobe

A cerebral lobe protected by the parietal bones, primarily concerned with the interpretation and integration of body sensory inputs, housing the primary somatosensory cortex.

Temporal Lobe

A cerebral lobe containing the auditory and olfactory cortices, participating in language recognition, and connecting to the amygdala and hippocampus.

Occipital Lobe

A cerebral lobe containing the primary visual cortex for visual information interpretation, reading comprehension, depth perception, and recognition of object movement.

Insula Lobe

A cerebral lobe responsible for visceral perception or awareness of internal organs, housing the gustatory cortex for taste perception, and enabling emotional self-awareness.

Sulcus

Grooves located on the surface of the cerebrum.

Gyrus

A fold of brain tissue located between sulci.

Fissure

A deep groove that separates the cerebral hemispheres.

Precentral Gyrus

A gyrus located on the frontal lobe that serves as the Primary Motor Cortex.

Postcentral Gyrus

A gyrus located on the parietal lobe that serves as the Primary Somatosensory Cortex.

Association Fibers

Axons (fibers) connecting different cortical areas on the same side of the cerebrum within the same hemisphere.

Commissural Fibers

Axon fibers connecting an area in one cerebral hemisphere with an area in the opposite hemisphere, the largest set being the corpus callosum.

Corpus Callosum

The largest set of commissural fibers in the brain, containing from $200$ to $300$ million axons crossing between hemispheres.

Projection Fibers

Central white matter tracts that connect the cerebral cortex with other areas in the CNS, such as deep nuclei, brainstem, cerebellum, or spine.

Reticular Activating System (RAS)

A functional system predominantly located in the pons and medulla oblongata that maintains consciousness, alertness, and functions in sleep and arousal.

Limbic System

A group of structures on the medial aspect of each cerebral hemisphere and diencephalon known as the 'emotional brain', participating in creating emotional states and processing vivid memories.

Cingulate Gyrus

An arch-shaped convolution situated just above the corpus callosum involved in decision making, planning, thought shifting, and interpreting pain as unpleasant.

Hippocampus

A plastic brain structure embedded deep in the temporal lobe that plays a major role in learning, memory, spatial processing, navigation, and consolidating memories during sleep.

Amygdala

Almond-shaped nuclei in the temporal lobe primarily involved in detecting and processing threatening stimuli, activating fight-or-flight responses, and tying emotional meaning to reactions.

Epithalamus

A division of the diencephalon that includes the pineal gland, which secretes melatonin and Dimethyl-tryptamine (DMT).

Thalamus

A region making up $80\%$ of the diencephalon containing approximately a dozen major nuclei that act as the 'gateway' to the cerebral cortex.

Hypothalamus

A region of the diencephalon lacking a protective Blood Brain Barrier that regulates the ANS, emotional responses, body temperature, hunger, thirst, and the endocrine system.

Substantia Nigra

A midbrain region containing dopaminergic cells that coordinate body movement, where a loss of $60$ to $80\%$ of these cells is linked to Parkinson's disease.

Corpora Quadrigemina

A midbrain structure composed of four bodies, containing the superior colliculi for vision reflexes and inferior colliculi for auditory reflexes.

Arbor Vitae

The inner tracts of myelinated axons in the cerebellum, meaning 'tree of life' due to its branching appearance.

Cerebellar Peduncles

Superior, middle, and inferior white matter tracts that relay information to refine body movements, learn skilled routines, and maintain balance and posture.

Pons

A brainstem structure meaning 'bridge' containing the pneumotaxic and apneustic centers that fine-tune the depth and rhythm of breathing set by the medulla oblongata.

Medulla Oblongata

The lowest part of the brainstem that transmits signals between the spinal cord and higher brain regions and houses vital centers regulating cardiac, vasomotor, and respiratory functions.

Cardiac Center

A vital center in the medulla oblongata that provides modulation and fine-tuning of heart rate and myocardial contractility force.

Vasomotor Center

A vital center in the medulla oblongata that regulates peripheral blood vessel diameter to control systemic blood pressure and blood flow.

Respiratory Center

A vital center in the medulla oblongata responsible for maintaining a steady breathing rhythm during eupnea by controlling the diaphragm via the phrenic nerve.

Phrenic Nerves

Paired nerves formed by fibers from C3-C5 that send motor impulses to contract the diaphragm muscle during inspiration.

Sciatic Nerve

The largest nerve arising from the sacral plexus (L4-S3) and the largest nerve in the body.

Falx Cerebri

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

Falx Cerebelli

A small triangular fold of dura mater that separates the two cerebellar hemispheres.

Tentorium Cerebelli

A fold of dura mater that separates the cerebellum from the cerebrum.

Choroid Plexuses

Networks of blood vessels located in the brain ventricles surrounded by ependymal cells that filter blood plasma to produce cerebrospinal fluid.

Hydrocephalus

An abnormal accumulation of cerebrospinal fluid in the ventricles or subarachnoid space of the brain, which can lead to increased intracranial pressure.