Talk:Brain Awareness Week 2012: Difference between revisions
From Embryology
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===Primitive vertebrates=== | ===Primitive vertebrates=== | ||
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* (hagfishes and lampreys) | * (hagfishes and lampreys) | ||
* cerebrum is a relatively simple structure receiving nerve impulses from the olfactory bulb. | * cerebrum is a relatively simple structure receiving nerve impulses from the olfactory bulb. | ||
| [[File:Lamprey cartoon.jpg|300px]] | |||
Lamprey | |||
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===Some fish and amphibians=== | ===Some fish and amphibians=== | ||
(Cartilaginous fish (sharks), lobe-finned fish, amphibians) | (Cartilaginous fish (sharks), lobe-finned fish, amphibians) | ||
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=== Ray-finned Fish=== | === Ray-finned Fish=== | ||
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* Cerebrum lateral and ventral regions inner surfaces bulge up into the ventricles. | * Cerebrum lateral and ventral regions inner surfaces bulge up into the ventricles. | ||
** these include both the basal nuclei and the various parts of the pallium (complex in structure in teleosts). | ** these include both the basal nuclei and the various parts of the pallium (complex in structure in teleosts). | ||
* Verebrum dorsal surface is membranous, and does not contain any nervous tissue. | * Verebrum dorsal surface is membranous, and does not contain any nervous tissue. | ||
| [[File:Zebrafish-icon.png|300px]] | |||
Zebrafish | |||
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In amniotes, the cerebrum becomes increasingly large and complex. | In amniotes, the cerebrum becomes increasingly large and complex. | ||
===Reptiles=== | ===Reptiles=== | ||
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* paleopallium is larger than in amphibians, and its growth has pushed the basal nuclei into the central regions of the cerebrum. | * paleopallium is larger than in amphibians, and its growth has pushed the basal nuclei into the central regions of the cerebrum. | ||
* Grey matter is generally located beneath the white matter | * Grey matter is generally located beneath the white matter | ||
** in some reptiles, grey matter spreads out to the surface to form a primitive cortex (anterior part of the brain). | ** in some reptiles, grey matter spreads out to the surface to form a primitive cortex (anterior part of the brain). | ||
| [[File:Rana_pipiens.jpg|300px]] | |||
Frog | |||
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===Birds=== | ===Birds=== | ||
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* enlarged compared to reptiles, due to the basal ganglia. | * enlarged compared to reptiles, due to the basal ganglia. | ||
** other areas remain primitive in structure. | ** other areas remain primitive in structure. | ||
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* above basal ganglia the HVC develops | * above basal ganglia the HVC develops | ||
** involved with learning complex tasks, such as song. | ** involved with learning complex tasks, such as song. | ||
| [[File:Chick E12.jpg|300px]] | |||
Chicken E12 | |||
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===Mammals=== | ===Mammals=== | ||
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* cortex covers almost the whole of the cerebral hemispheres (greatest in primates). | * cortex covers almost the whole of the cerebral hemispheres (greatest in primates). | ||
** paleopallium is pushed to the ventral surface of the brain, where it becomes the olfactory lobes | ** paleopallium is pushed to the ventral surface of the brain, where it becomes the olfactory lobes | ||
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** corpus callosum connects the two hemispheres. | ** corpus callosum connects the two hemispheres. | ||
* surface folding found only in higher mammals. | * surface folding found only in higher mammals. | ||
| [[File:Dog-adult.jpg|300px]] | |||
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Revision as of 14:57, 14 March 2012
Cerebrum Comparative Anatomy
- All brains have a similar mechanism of early development, neural plate, tube, etc.
- All brains will have similar regions with similar functions.
- Each animal brain though will end up a different size, shape and complexity (overall and of regions).
- The information shown below is a detailed comparison of different species cerebrum development.
This Information is beyond K12 level and not part of today's demonstration.
Primitive vertebrates
|
Lamprey |
Some fish and amphibians
(Cartilaginous fish (sharks), lobe-finned fish, amphibians)
- remains mainly devoted to olfactory sensation.
- Cerebrum divided into 3 regions.
- ventral - forms the basal nuclei, and contains fibres connecting the rest of the cerebrum to the thalamus.
- lateral - forms the paleopallium.
- dorsal - forms the archipallium.
Ray-finned Fish
In amniotes, the cerebrum becomes increasingly large and complex.
Reptiles
Birds
Mammals
Terms
- Cerebral cortex - (grey matter, cortex) Embryonic structure that will form the cerebral cortex of the brain. Formed in sequence from neural tube, prosencephalon (primary vesicle), telencephalon (secondary vesicle) then cerebrum or cortex.
- Cerebellum - (Latin, cerebellum = little brain) Formed from the rhombencephalon (hindbrain), it is required for coordinated motor activities.
- Diencephalon - At the level of the diencephalon that the optic stalks (optic nerve) extends from the brain. The diencephalon lumen (cavity of the neural tube) will form the third ventricles.
- Encephalon - brain.
- Midbrain - The embryonic neural tube region that will form midbrain structures of the tectum (roof of the midbrain, auditory and visual reflexes) and tegmentum (floor of the midbrain, several brain nuclei) in the adult brain. The mesencephalon is the middle of the 5 secondary brain vesicles formed from the mesencephalon of the primary brain vesicle (there are 3 primary brain vesicles). The mesencephalon lumen (cavity of the neural tube) will form the midbrain aqueduct.
- Telencephalon - (endbrain) The embryonic neural tube region that will form cerebral hemispheres (neocortex, basal nuclei, palaeocortex, archicortex). The telencephalon is the most anterior of the 5 secondary brain vesicles formed from division of the prosencephalon (forebrain) primary brain vesicle (there are 3 primary brain vesicles). The telencephalon lumen (cavity of the neural tube) will form the lateral ventricles.
Pons -
Medulla -