Organization of the Nervous System and the Brain

Flashcards on the organization of the nervous system and the brain.

Central Nervous System (CNS)

Includes the brain and spinal cord; responsible for information integration and coordinated activity.

Peripheral Nervous System (PNS)

Consists of everything outside the brain and spinal cord, including spinal nerves and cranial nerves; responsible for transmitting signals.

Somatic System

Responsible for conscious decisions and body movements.

Autonomic System

Controls involuntary functions like breathing and heart rate.

Neuroglial Cells

Support cells in the nervous system, including astrocytes, ependymal cells, microglia, oligodendrocytes, and Schwann cells.

Astrocytes

Maintain the blood-brain barrier, helping to control the interface between blood and the brain.

Ependymal Cells

Line the inner parts of the brain and spinal cord, facilitating cerebrospinal fluid movement.

Microglia

Act as immune defense cells in the brain.

Oligodendrocytes

Form myelin sheaths around axons in the central nervous system.

Schwann Cells

Form myelin sheaths around axons in the peripheral nervous system.

Myelin Sheath

A fatty protective layer that insulates nerve cells and allows signals to move faster.

Cell Body

Also called the soma; the main part of the neuron where organelles are located.

Dendrites

Receive signals and transmit them to the cell body.

Axon

Sends signals away from the cell body to other neurons or cells.

Nucleus

A collection of neuronal cell bodies in the CNS.

Ganglion

A collection of neuronal cell bodies in the PNS.

Dorsal Root Ganglion

Helps with orientation and indicates the posterior side of the spinal cord.

Dorsal Root

Made of axons and transmits sensory information.

Tract

A collection of axons in the CNS.

White Matter

Composed primarily of myelinated axons.

Gray Matter

Composed of cell bodies and dendrites.

Cerebrum

The largest part of the brain, divided into two hemispheres.

Cerebellum

Located beneath the cerebrum; responsible for motor coordination and balance.

Brain Stem

Includes the midbrain, pons, and medulla oblongata; controls basic life functions.

Gyri

Elevated ridges on the surface of the brain.

Sulci

Shallow grooves between gyri

Fissures

Very deep grooves between gyri

Longitudinal Fissure

Divides the cerebral hemispheres.

Transverse Fissure

Separates the cerebellum from the cerebrum.

Lateral Fissure

Separates the frontal and parietal lobes from the temporal lobe.

Central Sulcus

Separates the frontal and parietal lobes; also significant for separating the precentral and postcentral gyri.

Parieto-occipital Sulcus

Separates the parietal and occipital lobes.

Precentral Gyrus

Initiates voluntary movement.

Postcentral Gyrus

Receives sensory information.

Association Areas

Responsible for complex integrative functions.

Contralateral

Means opposite; each hemisphere controls the contralateral side of the body.

Broca's Area

Controls motor movements for speech.

Wernicke's Area

Controls speech interpretation.

Commissural Fibers

Connects gray matter area between two hemispheres

Association Fibers

Connect parts within the same hemisphere.

Projection Fibers

Fibers connecting the cerebral cortex to the other pars of CNS

Basal Nuclei

Influences motor function by regulating the initiation and termination of movements.

Thalamus

A major relay center for sensory information (except smell).

Hypothalamus

Regulates the body's internal environment and homeostasis and connects to the pituitary gland.

Pineal Gland

Produces melatonin and helps regulate sleep-wake cycles.

Superior Colliculi

Involved in vision.

Inferior Colliculi

Involved in hearing.

Substantia Nigra

Contains pigmented material and degenerates in Parkinson's disease.

Pons

Pathway for descending tracts from the cortex to the cerebellum.

Medulla Oblongata

Autonomic reflex center housing important visceral motor nuclei

Cerebellum

Responsible for timing, patterns, and smoothness of skeletal muscle contractions.

Arbor Vitae

White matter on the outside of the cerebellar cortex that looks like leaves on a tree.