The brain is located in the cranial cavity and can be divided into brainstem, cerebellum, diencephalon, and teleencephal. The telencephalon is a part of the brain.
It is made up of the left and right cerebral hemispheres, and the corpus callosum connects the two hemispheres.
a) The shape of the cerebral hemispheres
1 Three sides
Each cerebral hemisphere can be divided into three faces: the upper lateral surface, the inner surface, and the lower surface.
2 Three interlophyl sulcus
* sulcus, lateral sulcus, parieto-occipital sulcus.
3 Five leaves
Frontal, parietal, occipital, temporal, insula.
4 Major sulcus.
1) Frontal lobe: anterior sulcus, superior frontal sulcus, inferior frontal sulcus, **anterior gyrus, superior frontal gyrus, middle frontal gyrus, inferior frontal gyrus.
2) Parietal lobe: posterior sulcus, posterior gyrus, angular gyrus, superior marginal gyrus, etc.
3) Temporal lobe: superior temporal sulcus, inferior temporal sulcus, superior temporal gyrus, middle temporal gyrus, inferior temporal gyrus, transverse temporal gyrus, etc.
4) Medial surface: cingulate sulcus, talar sulcus, lateral collateral sulcus, cingulate gyrus, paralobule, parahippocampal gyrus, etc.
5) Below: olfactory bulbs, olfactory tracts, etc.
b) Internal structures of the cerebral hemispheres.
1 Cerebral cortex functional area.
1) Somatic sensory area: posterior gyrus and posterior paralobule.
2) Somatic motor area: anterior gyor gyrus and anterior paralobule.
3) Visual area: cortex on both sides of the talar sulcus.
4) Auditory area: transverse temporal gyrus.
5) Language center.
1) Auditory language center: superior marginal gyrus.
2) Visual language center: angular gyrus.
3) Writing center: posterior part of the middle frontal gyrus.
4) Motor language center: posterior inferior frontal gyrus.
2 Basal nucleus.
It is a mass of gray matter embedded in the medulla of the brain, located at the base of the brain. It mainly includes the screen-like nucleus, caudate nucleus, lenticular nucleus, amygdala, etc.
Striatum: The caudate nucleus and lenticular nucleus are collectively called the striatum. The main function is to maintain the tone of skeletal muscles and coordinate the movement of muscle groups.
3 Cerebral medulla.
1) Liaison fibers: connect the ipsilateral cerebral hemispheres.
2) Commissural fibers: i.e., corpus callosum.
3) Projection fibers: mainly internal capsules.
Internal capsule: located between the dorsal thalamus, caudate nucleus, and lenticular nucleus, and consists of ascending sensory fibers and descending motor fibers. It is in the shape of " in the horizontal section of the brain, and is divided into three parts: the forelimb of the internal capsule, the knee of the internal capsule, and the hindlimb of the internal capsule.
1) Internal capsule forelimb: located between the dorsal thalamus and the head of the caudate nucleus.
2) Internal capsular hind limb: located between the dorsal thalamus and the lenticular nucleus. There are mainly corticospinal tracts, spinothalamic tracts, optic radiation and other fiber bundles through.
3) Inner capsule knee: located at the intersection of the forelimb of the internal capsule and the hind limb of the internal capsule, through which the cortical nuclear tract passes.
Damage to one internal capsule can cause loss of depth and superficiality in the contralateral limb and paralysis of skeletal muscles.