brain diagrams

Can you guess what will happen if there is no folds in the cerebral cortex ?, there would be extremely great brain ,, in this topic we are talking about the brain gyri and sulci using brain diagrams and images .

brain diagram describing the lateral surface : 

Major dependable landmarks separate the forebrain into lobes; the lateral

(sylvian) fissure separates the temporal lobe below from the

parietal and frontal lobes above, and the central sulcus separates

the parietal and frontal lobes from each other. Several of

the named gyri are associated with specific functional activities,

such as the precentral gyrus (motor cortex) and the postcentral

gyrus (primary sensory cortex). Some gyri, such as the

superior, middle, and inferior frontal and temporal gyri, serve

as anatomical landmarks of the cerebral cortex. The insula,

the fifth lobe of the cerebral cortex, is deep to the outer cortex

and can be seen by opening the lateral fissure.

Some circumscribed regions of the cerebral hemisphere are

associated with specific functional activities, including the

motor cortex, the supplemental and premotor cortices, the

frontal eye fields, the primary sensory cortex, and other association

regions of the sensory cortex. Part of the auditory

cortex is visible at the inferior edge of the lateral fissure (the

transverse temporal gyrus of Heschl). Part of the visual cortex

is visible at the occipital pole. Language areas of the left

hemisphere include Broca’s area (expressive language) and

Wernicke’s area (receptive language). Damage to these cortical

regions results in loss of specific functional capabilities.

There is some overlap between functional areas and named

gyri (e.g., the motor cortex and the precentral gyrus), but

there is no absolute concordance.

Brodmann’s areas of the cerebral cortex have unique architectural

characteristics in terms of the thickness and layering of

the cerebral cortex; this knowledge is based on histological observations

originally made by Korbinian Brodmann in 1909.

His numbering of cortical areas is still used as a shorthand

for describing the functional regions of the cortex, particularly

those related to sensory functions. Some overlap exists among

functional areas. For example, the motor cortex is area 4; the

primary sensory cortex includes areas 3, 1, and 2; and the primary

visual cortex is area 17.

brain diagram describing the medial surface : 

The entire extent of the neuraxis, from the spinomedullary

junction through the brain stem, diencephalon, and telencephalon,

is visible in a midsagittal section. The corpus callosum,

a major commissural fiber bundle interconnecting the

two hemispheres, is a landmark separating the cerebral cortex

above from the thalamus, fornix, and subcortical forebrain

below. The ventricular system, including the interventricular

foramen (of Munro); the third ventricle (diencephalon); the

cerebral aqueduct (midbrain); and the fourth ventricle (pons

and medulla), is visible in a midsagittal view. This subarachnoid

fluid system provides internal and external protection

to the brain and also may serve as a fluid transport system

for important regulatory molecules. The thalamus serves as

a gateway to the cortex. The hypothalamic proximity to the

median eminence (tuber cinereum) and the pituitary gland

reflects the important role of the hypothalamus in regulating

neuroendocrine function. A midsagittal view also reveals the

midbrain colliculi, sometimes called the visual (superior) and

auditory (inferior) tecta.

When the brain stem is removed, a midsagittal view reveals

the C-shaped course of the fornix, extending from the hippocampal

formation in the temporal lobe to the septum and

hypothalamus. Temporal lobe structures, such as the parahippocampal

cortex, the dentate gyrus and fimbria of the hippocampus,

and the uncus (olfactory cortex) also are visible.

In the hypothalamus, the caudal mammillary bodies and the

interconnecting pathway to the thalamus, the mammillothalamic

tract, are revealed. 

A, Lobes and functional areas. The cingulate cortex is labeled

the limbic lobe, reflecting its association with other limbic

forebrain structures and with hypothalamic control of the

autonomic nervous system. Functional areas of the cortex,

particularly those involved with vision, are best seen on a

midsagittal view. The sensory and motor cortices associated

with the lower extremities are located medially and are supplied

with blood by the anterior cerebral artery. This region

is selectively vulnerable to specific vascular (anterior cerebral

artery infarct) and mass (parasagittal meningioma) lesions

that result in contralateral motor and sensory deficits of the

lower extremity. B, Brodmann’s areas of the cerebral cortex

are labeled on this midsagittal view of the brain. The major

regions are the primary (17) and associative (18, 19) visual

cortices, and the continuation of areas 4 (motor) and areas

3, 1, and 2 (primary sensory) onto the paracentral lobule in

the midline.

brain diagrams describing the basal surface : 

Removal of the brain stem and cerebellum by a cut through the

midbrain exposes the underlying cerebral cortex, the base of

the diencephalon, and the basal forebrain. Basal hypothalamic

landmarks, from caudal to rostral, include the  mammillary

bodies, tuber cinereum, pituitary gland, and optic chiasm.

The proximity of the pituitary to the optic chiasm is important

because bitemporal hemianopsia can result from optic

chiasm fiber damage, often an early sign of a pituitary tumor.

The genu and splenium of the corpus callosum are revealed

in this view. In the cross-section of the midbrain, the superior

colliculus, cerebral aqueduct, periaqueductal gray, red nucleus,

substantia nigra, and cerebral peduncles are shown.

This view provides information about the medial temporal

lobe on the left side of the brain, especially cortical regions

associated with the hippocampal formation, the amygdaloid

nuclei, and the olfactory system. On the right side of the brain,

Brodmann’s areas are noted.

brain diagrams using computed tomography scans : 

A and B, Computed tomography (CT) is an x-ray–based imaging

approach that is used to view the brain, particularly

when looking for differences in tissue density such as the presence

of blood. The use of spiral (helical) scanners can quickly

provide access to views of slices through the brain at the desired

thickness. CT delineates soft tissue, fluid, and bone and

can be used with contrast to image blood vessels or to reveal

the presence of a tumor caused by a disrupted blood-brain

barrier that allows leakage of the contrast agent into the surrounding

extracellular space of the brain.

brain diagrams using magnetic resonance image axial and cronal t1 weighted  images : 

A, axial view. B, sagittal view. Magnetic resonance imaging

(MRI) uses short bursts (radiofrequency pulses) of electromagnetic

waves that are sent into the magnet and are absorbed by

protons in the tissues of the patient in the scanner. The pulses

cause alignment of the protons as the result of raised energy

levels; that is followed by a relaxation phase in which the protons

return to a lower energy level. During the relaxation procÂ

ess, a detector records the emitted energy, and a computer

provides a uniform image of the scanned tissue. The intervals

(milliseconds) between the pulses (repetition time, TR) and

the intervals between the collection times of the emitted energy

(echo time, TE) provide various contrast information, which

are indicated by contrast weighting. Short TR and TE intervals

result in T1-weighted images, whereas longer TR and TE intervals

result in T2-weighted images. The T1-weighted images

are particularly useful for viewing normal brain structures and

are particularly useful for viewing the brain stem and the cervical

and thoracic spinal cord. The T2-weighted images are

particularly useful for revealing pathology, such as infarcts,

tumors, edema, and demyelination. A contrast agent such as

gadolinium can be used to delineate a tumor because of its

ability to leak across the blood-brain barrier

brain diagrams using magnetic resonance imaging axial and sagittal t2 - weighted images : 

A, axial view. B, sagittal view. T2-weighted images are particularly

useful for imaging the ventricular system and the cisterns

of cerebrospinal fluid.

positron emission tomography scaning : 

Positron emission tomography (PET) scanning is designed to

assess the distribution of tracers labeled with positron-emitting

nuclides, such as carbon-11 (11C), nitrogen-13 (13N), oxygen-

15 (15O), and fluorine-18 (18F). Fluorodeoxyglucose (FDG), a

glucose analogue labeled with 18F, can cross the blood-brain

barrier. The metabolic products of FDG become  immobile

and trapped where the molecule is first used, thereby permitting

FDG to be used to map glucose uptake in the brain.

This is a valuable tool for investigating subtle physiological

processes related to neurological diseases. The distribution of

FDG can be localized and reconstructed using standard tomographic

techniques that show the tracer distribution throughout

the body or brain. In this example of axial, sagittal, and

coronal views, the transmission measurement and correction

was performed immediately following PET acquisition using a

16-slice CT unit. The PET and CT images were automatically

fused by anatomical coregistration software (shown as colored

images).

 

In the conclusion I have to notice that we explained good information about the cerebral cortex 

and used alot of brain diagrams and images so 

i hop it can help 

best regards