Cerebrum

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(Redirected from
Telencephalon
)
"Cerebra" redirects here. For the charity, see Cerebra (charity). For the character, see X-Men 2099.
Cerebrum
The lobes of the cerebral cortex include the frontal (blue), temporal (green), occipital (red), and parietal (yellow) lobes. The cerebellum (unlabeled) is not part of the telencephalon.
Diagram depicting the main subdivisions of the embryonic vertebrate brain.
Details
Pronunciation/ˈsɛrɪbrəm/, /sɪˈriːbrəm/
Arteryanterior cerebral, middle cerebral, posterior cerebral
Veincerebral veins
Identifiers
Latincerebrum
MeSHD054022
NeuroLex IDbirnlex_1042
TA98A14.1.03.008
A14.1.09.001
TA25416
THH3.11.03.6.00001
TEE5.14.1.0.2.0.12
FMA62000
Anatomical terms of neuroanatomy

The cerebrum (pl.: cerebra), telencephalon or endbrain

ventral telencephalon, or subpallium, becomes the basal ganglia. The cerebrum is also divided into approximately symmetric left and right cerebral hemispheres.

With the assistance of the cerebellum, the cerebrum controls all voluntary actions in the human body.

Structure

Location of the human cerebrum (red).

The cerebrum is the largest part of the brain. Depending upon the position of the animal it lies either in front or on top of the brainstem. In humans, the cerebrum is the largest and best-developed of the five major divisions of the brain.

The cerebrum is made up of the two cerebral hemispheres and their

cerebral cortices (the outer layers of grey matter), and the underlying regions of white matter.[2] Its subcortical structures include the hippocampus, basal ganglia and olfactory bulb. The cerebrum consists of two C-shaped cerebral hemispheres, separated from each other by a deep fissure called the longitudinal fissure
.

Cerebral cortex

Surface of the cerebrum

The cerebral cortex, the outer layer of grey matter of the cerebrum, is found only in mammals. In larger mammals, including humans, the surface of the cerebral cortex folds to create gyri (ridges) and sulci (furrows) which increase the surface area.[3]

The cerebral cortex is generally classified into four

insular lobe, a part of the cerebral cortex folded deep within the lateral sulcus
that separates the temporal lobe from the parietal and frontal lobes, is located within each hemisphere of the mammalian brain.

Cerebral hemispheres

The cerebrum is divided by the

bilateral symmetry between the hemispheres, while lateralization tends to increase with increasing brain size.[6] The lateralization of brain function
looks at the known and possible differences between the two.

Development

In the developing vertebrate

optic vesicles (future retina).[8]
The dorsal telencephalon then forms two lateral telencephalic vesicles, separated by the midline, which develop into the left and right cerebral hemispheres. Birds and fish have a dorsal telencephalon, like all vertebrates, but it is generally unlayered and therefore not considered a cerebral cortex. Only a layered cytoarchitecture can be considered a cortex.

Functions

Note: As cerebrum is a gross division with many subdivisions and sub-regions, it is important to state that this section lists functions that cerebrum as a whole serves. See main articles on cerebral cortex and basal ganglia for more information. The cerebrum is a major part of the brain, controlling emotions, hearing, vision, personality and much more. It controls all precision of voluntary actions.

motor neuron disease. This kind of damage results in loss of muscular power and precision rather than total paralysis
.

It functions as the center of sensory perception, memory, thoughts and judgement; the cerebrum also functions as the center of voluntary motor activities.

Sensory processing

The primary sensory areas of the cerebral cortex receive and process

olfactory
information. Together with association cortical areas, these brain regions synthesize sensory information into our perceptions of the world.

Olfaction

Main article: Sense of smell

The olfactory bulb, responsible for the sense of smell, takes up a large area of the cerebrum in most vertebrates. However, in humans, this part of the brain is much smaller and lies underneath the frontal lobe. The olfactory sensory system is unique since the neurons in the olfactory bulb send their axons directly to the olfactory cortex, rather than to the thalamus first. The olfaction is also the only sense that is represented by the ipsilateral side of the brain. Damage to the olfactory bulb results in a loss of olfaction (the sense of smell).

Language and communication

Main article: Language

Speech and language are mainly attributed to the parts of the cerebral cortex. Motor portions of language are attributed to Broca's area within the frontal lobe. Speech comprehension is attributed to Wernicke's area, at the temporal-parietal lobe junction. These two regions are interconnected by a large white matter tract, the arcuate fasciculus. Damage to the Broca's area results in expressive aphasia (non-fluent aphasia) while damage to Wernicke's area results in receptive aphasia
(also called fluent aphasia).

Learning and memory

Main article: Memory

Explicit or declarative (factual) memory formation is attributed to the

HM had both his left and right hippocampus surgically removed to treat chronic [temporal lobe epilepsy]. After surgery, HM had anterograde amnesia
, or the inability to form new memories.

Implicit or procedural memory, such as complex motor behaviors, involves the basal ganglia.

Short-term or working memory involves association areas of the cortex, especially the dorsolateral prefrontal cortex, as well as the hippocampus.

Other animals

In the most primitive vertebrates, the

basal nuclei, and contains fibres connecting the rest of the cerebrum to the thalamus. Above this, and forming the lateral part of the cerebrum, is the paleopallium, while the uppermost (or dorsal) part is referred to as the archipallium. The cerebrum remains largely devoted to olfactory sensation in these animals, in contrast to its much wider range of functions in amniotes.[9]

In

ventricles; these include both the basal nuclei and the various parts of the pallium and may be complex in structure, especially in teleosts. The dorsal surface of the cerebrum is membranous, and does not contain any nervous tissue.[9]

In the amniotes, the cerebrum becomes increasingly large and complex. In reptiles, the paleopallium is much larger than in amphibians and its growth has pushed the basal nuclei into the central regions of the cerebrum. As in the lower vertebrates, the grey matter is generally located beneath the white matter, but in some reptiles, it spreads out to the surface to form a primitive cortex, especially in the anterior part of the brain.[9]

In

dolphins are the only species (other than humans) to have cerebra accounting for as much as 2 percent of their body weight.[10]

The cerebra of

archosaurs, with few clear parallels to that experienced by mammals and their therapsid
ancestors.

Additional images

  • Cerebrum. Lateral face. Deep dissection.
    Cerebrum. Lateral face. Deep dissection.
  • Cerebrum. Medial face. Deep dissection.
    Cerebrum. Medial face. Deep dissection.

See also

This article uses anatomical terminology.

References

  1. ^ "BrainInfo". braininfo.rprc.washington.edu.
  2. ISBN 9780748736348
    . Retrieved 27 January 2015.
  3. ISBN 9780195028850
    . Retrieved 25 January 2015.
  4. ^
    ISBN 9780781765213
    . Retrieved 28 January 2015.
  5. S2CID 7399128
    .
  6. S2CID 2406618
    .
  7. ISBN 978-0-87893-978-7
    .
  8. ISBN 978-0-07-139011-8
    .
  9. ^
    ISBN 0-03-910284-X
    .
  10. ^ T.L. Brink (2008). "Unit 4: The Nervous System.". Psychology: A Student Friendly Approach (PDF). p. 62.
  11. PMID 15685220
    .
  12. PMID 16553307
    .

External links

Wikimedia Commons has media related to Telencephalon.
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