FACTOID # 28: Austin, Texas has more people than Alaska.
 
 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 > Pretectum

Pretectum is a structure located in the forebrain. It receives binocular input from the eyes and is involved with the pupillary light reflex. In the anatomy of vertebrates, the prosencephalon is a part of encephalon, or brain. ... Binocular vision is vision in which both eyes are used synchronously to produce a single image. ... Closeup of a blue-green human eye. ... In medicine, pupil constriction (also known as the pupillary reflex) is reduction of pupil size. ...


The pretectum, after receiving binocular input, outputs to the Edinger-Westphal nucleus (which is a pre-ganglionic nucleus also located in the midbrain) and to the Cilio-Spinal Nucleus (Budge), which is located in the VIII cervical and I, II thoracic vertebral segments. The Edinger-Westphal nucleus and Budge's Cilio-Spinal Nucleus project onto the ciliary ganglion, whose output controls pupillary diameter (mydriasis or myosis). The Edinger-Westphal nucleus controls the Pupillary Sphincter muscle (used in situations of bright light to reduce the exposure of the retina) and the Ciliary Muscle (used for eye focusing and accommodation). The Cilio-Spinal Nucleus controls the Pupillary Dilator Muscle (used in situations of dark light, to increase the exposure of the retina) The Edinger-Westphal nucleus is the accessory parasympathetic nucleus of the oculomotor nerve, supplying the constricting muscles of the iris. ... The ciliary ganglion is small parasympathetic ganglion lying in the orbit between the optic nerve and the lateral rectus muscle that is associated with the nasociliary nerve (a branch of the ophthalmic division of the trigeminal nerve). ... An abnormally dilated pupil. ... Miosis is a medical term for constriction of the pupil. ... Light from a single point of a distant object and light from a single point of a near object being brought to a focus by changing the curvature of the lens. ...


See also

The oculomotor nerve () is the third of twelve paired cranial nerves. ... In biological anatomy, the mesencephalon (or midbrain) is the middle of three vesicles that arise from the neural tube that forms the brain of developing animals. ... Human brain image constructed from MRI data // Brain (neural tube) Brainstem (rhombencephalon),(mesencephalon) Rhombencephalon (hindbrain) Metencephalon pons fourth ventricle cerebellum cerebellar vermis cerebellar hemispheres anterior lobe posterior lobe flocculonodular lobe cerebellar nuclei fastigial nucleus globose nucleus emboliform nucleus dentate nucleus Myelencephalon medulla oblongata medullary pyramids Mesencephalon (midbrain) tectum inferior colliculi...

External links


BrainMaps is an NIH-funded interactive zoomable high-resolution digital brain atlas and virtual microscope that is based on more than 10 million megapixels (30 terabytes) of scanned images of serial sections of both primate and non-primate brains and that is integrated with a high-speed database for querying...

Mesencephalon (midbrain)

cerebral peduncle: midbrain tegmentum (periaqueductal gray, ventral tegmentum, nucleus raphe dorsalis), pretectum, substantia nigra, red nucleus, pedunculopontine nucleus, medial longitudinal fasciculus, medial lemniscus, rubrospinal tract, lateral lemniscus In biological anatomy, the mesencephalon (or midbrain) is the middle of three vesicles that arise from the neural tube that forms the brain of developing animals. ... The cerebral peduncle, by most classifications, is everything in the mesencephalon except the tectum. ... The midbrain tegmentum is part of the midbrain extending from the substantia nigra to the cerebral aqueduct. ... Periaqueductal Gray (PAG; also called the central gray) is the midbrain grey matter that is located around the cerebral aqueduct within the midbrain. ... Grays FIG. 712– Transverse section of mid-brain at level of superior colliculi. ... The nucleus raphe dorsalis consists of rostral and caudal subdivisions. ... The substantia nigra (Latin for black substance) is a portion of the midbrain thought to be involved in certain aspects of movement and attention. ... The red nucleus is a structure in the rostral midbrain involved in motor coordination. ... The pedunculopontine nucleus (PPN) is located in the brainstem, caudal to the substantia nigra and adjacent to the superior cerebellar peduncle. ... 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 medial lemniscus, also known as Reils band or Reils ribbon, is a pathway in the brainstem that carries sensory information from the gracile and cuneate nuclei to the thalamus. ... The rubrospinal tract is part of the indirect extra-pyramidal tract and is responsible for large muscle movement such as the arms and the legs. ... The lateral lemniscus is a tract of axons in the brainstem that carries information about sound to the inferior colliculus of the midbrain. ...


tectum: corpora quadrigemina, inferior colliculi, superior colliculi The tectum is the dorsal part of the midbrain, derived in embryonic development from the alar plate of the neural tube. ... Corpora quadrigemina (Latin: four twins) is the collective name given to both pairs of the inferior and superior colliculi. ... The paired inferior colliculi together with the superior colliculi form the eminences of the corpora quadrigemina. ... The superior colliculus is part of the brain that sits below the thalamus and surrounds the pineal gland in the mesencephalon of vertebrate brains. ...


cerebral aqueduct: oculomotor nucleus, trochlear nucleus, Edinger-Westphal nucleus The mesencephalic duct, also known as the Aqueduct of Silvius or the cerebral aqueduct, contains cerebrospinal fluid (CSF), is within the mesencephalon (or midbrain) and connects the third ventricle in the thalamus (or diencephalon) to the fourth ventricle, which is between the pons and cerebellum. ... The fibers of the oculomotor nerve arise from a nucleus in the midbrain, which lies in the gray substance of the floor of the cerebral aqueduct and extends in front of the aqueduct for a short distance into the floor of the third ventricle. ... The nucleus of the trochlear nerve is located in the midbrain, at the level of the inferior colliculus. ... The Edinger-Westphal nucleus is the accessory parasympathetic nucleus of the oculomotor nerve, supplying the constricting muscles of the iris. ...


  Results from FactBites:
 
Emx2 directs the development of diencephalon in cooperation with Otx2 -- Suda et al. 128 (13): 2433 -- Development (8053 words)
1, ventral thalamus; 2, dorsal thalamus; 3, anterior pretectum; and 4, posterior pretectum.
to the posterior pretectum, was not sharply delineated (Fig.
The ventral and dorsal thalamus, epithalamus and anterior pretectum
Pretectum - Wikipedia, the free encyclopedia (202 words)
Pretectum is a structure located in the forebrain.
The pretectum, after receiving binocular input, outputs to the Edinger-Westphal nucleus (which is a pre-ganglionic nucleus also located in the midbrain) and to the Cilio-Spinal Nucleus (Budge), which is located in the VIII cervical and I, II thoracic vertebral segments.
The Edinger-Westphal nucleus and Budge's Cilio-Spinal Nucleus project onto the ciliary ganglion, whose output controls pupillary diameter (mydriasis or myosis).
  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