Neuroscience

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Neuroscience

• Introduction / Terminology

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Neuroscience

• Neuroscience is the study of the nervous system.
• It is a composite of several disciplines of
  study
• Neuroanatomy, neurophysiology, neurology,
  neuropathology, neuropharmacology, behavioral
  sciences, and cell biology.

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Neuroanatomical Directional Terms(5 paired terms)

• Medial-lateral
• Medial means towards the median plane. Lateral
  means away from the median plane.
• Anterior-posterior
• Above the midbrain, anterior means towards the
  front of the brain and posterior means towards
  the back of the brain.
• At and below the midbrain, anterior means toward
  the ventral surface of the body and posterior
  means toward the dorsal surface of the body.
• Rostral-caudal
• Above the midbrain, rostral means toward the
  front of the brain and caudal means towards the
  back of the brain.
• At and below the midbrain, rostral means towards
  the cerebral cortex and caudal means towards the
  sacral end (or bottom) of the spinal cord.

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Neuroanatomical Directional Terms(5 paired terms)

• Dorsal-ventral
• Rostral to the midbrain, dorsal refers to the top
  of the brain and ventral refers to the bottom of
  the brain.
• At the level of the midbrain and caudal to it,
  dorsal means towards the posterior surface of the
  body and ventral refers to the anterior surface
  of the body.
• Superior-inferior
• Superior means towards the top of the cerebral
  cortex and inferior means toward the bottom of
  the spinal cord.

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Neuroanatomical Directional Terms
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Neuroanatomical Terms

• Ipsilateral-contralateral
• Ipsilateral means on the same side with reference
  to a speciifc point.
• Contralateral means on the opposite side.
• Commissure and decussation
• Commissure is a group of nerve fibers connecting
  one side of the brain with the other.
• Decussation is the crossing over of these nerve
  fibers.
• Neuron
• A neuron is the anatomical and functional unit of
  the nervous system, which consists of a nerve
  cell body, dendrites, and an axon.

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Clusters of Neuronal Cell Bodies

• Nucleus
• A nucleus is a cluster of neuronal cell bodies in
  the central nervous system.
• These neurons typically have a similar
  appearance, receive information from similar
  sources, project their axons to similar targets,
  and share similar functions.
• Ganglia
• A ganglion is a cluster of neuronal cell bodies
  in the peripheral nervous system.

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Bundles of Axons

• Tract
• A tract is a bundle of axons in the central
  nervous system.
• These typically pass from a given nucleus to a
  common target.
• Tracts interconnect neurons in the spinal cord
  and brain.
• Nerve
• A nerve is a bundle of axons in the peripheral
  nervous system.
• Cranial nerves connect the brain to the
  periphery.
• Spinal nerves connect the spinal cord to the
  periphery.

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White and Gray Matter

• White matter
• The white matter consists of aggregations of
  primarily myelinated and some unmyelinated axons.
  (Myelin is whitish in color)
• Gray matter
• The gray matter consists of neuronal cell bodies,
  dendrites, unmyelinated axons, axon terminals,
  and neuroglia. (Nissl bodies impart a gray color)

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Glial Cells

• Glial cells are non-neural cells that form the
  interstitial tissue of the nervous system.
• The comprise half the volume of the CNS.
• They are typically smaller than neurons, but 5 to
  50 times more numerous.
• They can multiply and divide.
• Gliomas are brain tumors derived from glia.

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Central and Peripheral Nervous Systems

• Anatomic subdivisions of the nervous system.
• The central nervous system (CNS) includes the
  brain and spinal cord.
• It is protected by 3 protective layers called the
  meninges.
• It has fluid filled chambers called ventricles.
• The bone of the skull and vertebral column
  surround and protect the brain and spinal cord
  respectively.
• The peripheral nervous system (PNS) consists of
  the spinal nerves, cranial nerves, peripheral
  nerves, enteric nervous system, nerve receptors.
  It is comprised of all neuronal tissue that is
  outside of the CNS.

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Autonomic and Somatic Nervous Systems

• Functional subdivisions of the nervous system.
• The autonomic nervous system innervates smooth
  muscle and glands.
• The somatic nervous system innervates
  musculoskeletal structures and the sense organs
  of the skin.