FACTOID # 8: Bookworms: Vermont has the highest number of high school teachers per capita and third highest number of librarians per capita.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Paramedian pontine reticular formation

The paramedian pontine reticular formation, or PPRF, is a brain region, without clearly defined borders, in the center of the pons. It is involved in the coordination of eye movements, particularly saccades. Comparative brain sizes In animals, the brain, or encephalon (Greek for in the head), is the control center of the central nervous system. ... Position of the pons in the human brain The pons (sometimes pons Varolii after Costanzo Varolio) is a knob on the brain stem. ... Eye movements are the voluntary or involuntary movements of the eye. ... A saccade is a fast movement of an eye, head, or other part of an animals body or of a device. ...

Contents


Inputs, outputs, functions

The PPRF is located anterior and lateral to the medial longitudinal fasciculus (MLF). It receives input from the superior colliculus via the predorsal bundle and from the frontal eye fields via frontopontine fibers. The rostral PPRF probably coordinates horizontal saccades; the caudal PPRF may be the generator of both horizontal and vertical saccades. In particular, activity of the excitatory burst neurons (EBNs) in the PPRF generates the "pulse" movement that initiates a saccade. In the case of horizontal saccades the "pulse" information is conveyed via axonal fibers to the abducens nucleus, initiating lateral eye movements. The angular velocity of the eye during horizontal saccade ranges from 100 to 700 degrees per second. Larger saccades have faster pulses; the PPRF is involved in this determination.[1] In human and zoological anatomy (sometimes called zootomy), several terms are used to describe the location of organs and other structures in the body of bilateral animals. ... The medial longitudinal fasciculus (MLF) is a group of axons on each side of the brainstem, that carry information about the direction that the eyes should move. ... The superior colliculus is part of the brain that sits below the thalamus and surrounds the pineal gland in the mesencephalon of vertebrate brains. ... // Human Brodmann area 8, or BA8, is part of the frontal cortex in the human brain. ... Drawing by Santiago Ramón y Cajal of cells in the pigeon cerebellum. ... An axon, or nerve fiber, is a long slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neurons cell body or soma. ... The abducens nucleus is the originating nucleus from which the abducens nerve emerges. ... Eye movements are the voluntary or involuntary movements of the eye. ... Angular velocity describes the speed of rotation. ... A degree (in full, a degree of arc, arc degree, or arcdegree), usually symbolized °, is a measurement of plane angle, representing 1/360 of a full rotation. ...


Lesions

Unilateral lesions of the PPRF produce characteristic findings:[2] A lesion is a non-specific term referring to abnormal tissue in the body. ...

  • Loss of horizontal saccades directed towards the side of the lesion, no matter the current position of gaze
  • Contralateral gaze deviation (acute lesions, such as early stroke, only)
  • Gaze-evoked lateral nystagmus on looking away from the side of the lesion
  • Bilateral lesions produce horizontal gaze palsy and slowing of vertical saccades

A stroke or cerebrovascular accident (CVA) occurs when the blood supply to a part of the brain is suddenly interrupted. ... Look up Nystagmus in Wiktionary, the free dictionary Nystagmus is rapid involuntary rhythmic eye movement, with the eyes moving quickly in one direction (quick phase), and then slowly in the other (slow phase). ... Ophthalmoparesis is a physical finding in certain neurologic illnesses. ...

See also

Ophthalmoparesis is a physical finding in certain neurologic illnesses. ... Internuclear ophthalmoplegia is a physical finding, or sign, that is a particular form of [[[ophthalmoparesis]]. It can affect either the right or left eye. ... A stroke or cerebrovascular accident (CVA) occurs when the blood supply to a part of the brain is suddenly interrupted. ...

References

  1. ^  Brazis, P.W., Masdeu, J.C., and Biller, J. Localization in Clinical Neurology, 4th edition. Lippincott, Williams, and Wilkins, Philadelphia, 2001; pp. 213-216. ISBN 0-7817-2843-6
  2. ^  Adapted from Leigh, R.J., and Zee, D.S. The Neurology of Eye Movements, 3rd edition. Oxford University Press, Oxford, England, 1999; p. 499. ISBN 0-19-512-972-5

External links


The University of Washington, founded in 1861, is a major public research university in Seattle, Washington. ...

Rhombencephalon (hindbrain)

MYELENCEPHALON: medulla oblongata, olivary body, arcuate nucleus of medulla, solitary nucleus, nucleus ambiguus Wikipedia does not have an article with this exact name. ... The myelencephalon is a developmental categorization of a portion of the central nervous system. ... Position of medulla oblangata in the human brain The medulla oblongata is the lower portion of the brainstem. ... In anatomy, the olivary bodies or simply olives (Latin oliva) are a pair of prominent oval structures in the medulla oblongata, the lower portion of the brainstem. ... Grays Fig. ... The solitary nucleus and tract are structures in the brainstem that carry and receive visceral sensation and taste from the facial (VII), glossopharyngeal (IX), vagus (X) cranial nerves, as well as the cranial part of the accessory nerve (XI). ... The nucleus ambiguus is a cranial nerve nucleus, located in the medulla oblongata, and handles the branchial motor functions of the ninth (glossopharyngeal) and tenth (vagus) cranial nerves. ...


METENCEPHALON: cerebellum (arbor vitae, cerebellar vermis), pons (pontine nuclei, fourth ventricle, obex, median aperture, paramedian pontine reticular formation, locus ceruleus, abducens nucleus) The metencephalon is a developmental categorization of portions of the central nervous system. ... Figure 1a: A human brain, with the cerebellum in purple. ... The arbor vitae (Tree of Life) refers to the cerebellar white matter, so called for its branched, tree-like appearance. ... Part of the structure of animal brains, the cerebellar vermis is a narrow, wormlike structure between the hemispheres of the cerebellum. ... Position of the pons in the human brain The pons (sometimes pons Varolii after Costanzo Varolio) is a knob on the brain stem. ... The pontine nuclei are a part of the pons which store the memory of intention during motor activity. ... The fourth ventricle is one of the four connected fluid-filled cavities within the human brain. ... IrOBEX (or just OBEX) is a communications protocol that facilitates the exchange of binary objects between devices. ... The Median Aperture of the brain (apertura medialis ventriculi quarte) or Foramen of Magendie is an opening in the hollow nerve tube, connecting the 4th ventricle of the brain with the subarachnoid space The median aperture along with the paired lateral apertures (foramina of Luschka) are the primary routes for... The Locus ceruleus, also spelled locus coeruleus, (Latin for the blue bit) is a nucleus in the brain stem (under the cerebellum in the caudal midbrain/rostral pons) apparently responsible for the physiological reactions involved in stress and panic. ... The abducens nucleus is the originating nucleus from which the abducens nerve emerges. ...


  Results from FactBites:
 
Studies of the Role of the Paramedian Pontine Reticular Formation in the Control of Head-Restrained and ... (369 words)
Studies of the Role of the Paramedian Pontine Reticular Formation in the Control of Head-Restrained and Head-Unrestrained Gaze Shifts -- SPARKS et al.
Studies of the Role of the Paramedian Pontine Reticular Formation in the Control of Head-Restrained and Head-Unrestrained Gaze Shifts
pontine reticular formation (PPRF) in the control of gaze are
Table of Contents (326 words)
A safe paramedian approach to the rhomboid fossa for surgical treatment of intrinsic brainstem lesions is based on detailed knowledge of the morphometric anatomy of superficially located motor structures.
The colliculus is a landmark for the nervus facialis, oculomotor nuclei, and the paramedian pontine reticular formation.
In the surgeon's view from the posterior approach, the colliculus covers an area of 5.7 mm in the mediolateral and 6.8 mm in the craniocaudal direction and is located 0.6 mm lateral to the median sulcus.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m