Superolateral Surface of Brain

Superolateral Surface of Brain.

The  cerebral hemispheres have complicated fold called gyri . The groves between the gyri are called are called sulki .

The apperence of sulki and gyri increases the surface area for the neurons many times, without increasing the size of brain.

On the superolateral surface, two sulci, the lateral and the central, can be easily identified. 

Lateral Sulcus : It is begins on the inferior surface . On reaching the the lateral surface, it divides into three rami. i.e Posterior ramus ,anterior horizontal & anterior ascending rami. The largest of these is posterior ramus. The posterior end of this ramus turns upwards into the temporal lobe. The oter rami of the lateral sulcus are the  

anterior horizontal & anterior ascending rami. They extend into the lower part of the frontal lobe

Central sulcus : The upper end of the sulcus extends for a shortdistance on to the medial surface. 

Lobes

Frontal lobe :  The superolateral surface of the frontal lobe is traversed by three main sulci and thus divided into four gyri. The precentral sulcus runs parallel to the central sulcus, separated from it by the precentral gyrus, the great cortical somatomotor area. The superior and inferior frontal sulci curve across the remaining part of the surface, dividing it into superior, middle, and inferior frontal gyri.

Frontal lobe ;            Sulki                          Gyri                

1.        Percentral                                            Percentral         
2.       Superior frontal                                  Superior frontal  
3.       Inferior frontal                                   Middle frontal   
4.                                                       Inferior Frontal   

Parietal Lobe : . The parietal lobe has two main sulci, which divide it into three gyri.

The postcentral sulcus lies parallel to the central sulcus, separated from it by the postcentral gyrus, the great somatic sensory cortical area. The remaining, larger part of the superolateral parietal surface is subdivided into superior and inferior parietal lobules (gyri) by the intraparietal sulcus, which runs backward from near the midpoint of the postcentral sulcus and usually extends into the occipital lobe, where it ends by joining the transverse occipital sulcus.

Parietal Lobe : 

  Sulki                          Gyri  

1.     Postcentral                                            Postcentral
2.    Intrapariental                                        Superior parital lobule 
3.                                                                  Inferior parital lobules                 

Tempopral lobe  :

The superior and inferior temporal sulci divide the temporal lobe into superior, middle and inferior temporal gyri.  

  Sulki                          Gyri  

1.            Superior temporal                         Superior temporal 
2.            Inferior tmporal                              Middle temporal 
3.                                                           Inferior tmporal    

Occipital lobe  :                                                                     Sulki                          Gyri  

1. Transvers occipital                      Arcus Parieto-occipitalis
2. Lateral occipital                           Superior occipital 
3. Lunate                                         inferior occipital  
4. Calcarine                                     Gyrus descendens