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The purpose of this part of the brain is to sustain fundamental homeostatic functions, which are self regulating processes organisms use to help their bodies adapt. The pons and medulla are major structures found there. A new region of the brain developed in mammals about 250 million years after the appearance of the hindbrain.
The cerebrum (pl.: cerebra), telencephalon or endbrain [1] is the largest part of the brain, containing the cerebral cortex (of the two cerebral hemispheres) as well as several subcortical structures, including the hippocampus, basal ganglia, and olfactory bulb. In the human brain, the cerebrum is the uppermost region of the central nervous system.
Typically, each body segment has one ganglion on each side, though some ganglia are fused to form the brain and other large ganglia. The head segment contains the brain, also known as the supraesophageal ganglion. In the insect nervous system, the brain is anatomically divided into the protocerebrum, deutocerebrum, and tritocerebrum.
The human brain undergoes gyrification during fetal and neonatal development. In embryonic development, all mammalian brains begin as smooth structures derived from the neural tube. A cerebral cortex without surface convolutions is lissencephalic, meaning 'smooth-brained'. [4]
Paleoneurobiology is the study of brain evolution by analysis of brain endocasts to determine endocranial traits and volumes. Considered a subdivision of neuroscience, paleoneurobiology combines techniques from other fields of study including paleontology and archaeology. It reveals specific insight concerning human evolution.
A gyrification index (GI) is a measure of the magnitude of cortical convolutions on the surface of the mammalian brain. [ 6 ] [ 35 ] Reptile's and bird's brains do not show gyrification. Mammals with a high GI are generally larger than those with a low GI; for example the pilot whale and bottlenose dolphin show the highest GI values.
In humans, cerebral convolutions appear at about five months and take at least into the first year after birth to fully develop. [12] [13] [14] There is a hierarchy of morphological development with the fissures and main sulci developing ahead of others. The first sulci to develop are the primary sulci, followed by secondary sulci.
The transverse temporal gyrus, also called Heschl's gyrus (/ ˈ h ɛ ʃ əl z ˈ dʒ aɪ r aɪ /) or Heschl's convolutions, is a gyrus found in the area of each primary auditory cortex buried within the lateral sulcus of the human brain, occupying Brodmann areas 41 and 42.