NeuroscienceIntroduction / TerminologyD

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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.

Dr. Michael P. Gillespie2

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.

Dr. Michael P. Gillespie3

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.

Dr. Michael P. Gillespie4

Neuroanatomical Directional Terms

Dr. Michael P. Gillespie5

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.

Dr. Michael P. Gillespie6

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.

Dr. Michael P. Gillespie7

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.

Dr. Michael P. Gillespie8

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.

Dr. Michael P. Gillespie11

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.

Dr. Michael P. Gillespie12