ANATOMY

inside "Brain"

Anatomy : Function : Neuron : Imaging : Research :

surface anatomy

image site author

The medial surface of the brain shows the midline surfaces of the cerebral hemispheres and the cingulate gyrus, and cut surfaces of corpus collosum, midbrain, pons, and cerebellum. The lateral view shows the lobes of the cerebral hemispheres.

These voxel movies may be slow to open, but they are short: voxel animation - spin a brain : voxel animation - rotate a skull

frontal lobes

image site author

The cerebral hemispheres comprise paired lobes: frontal, temporal, parietal and occipital.

frontal lobes

image site author, adapted from NEJM Digitally Remastered image

Arguably the most famous neurological accident affected Phineas Gage in 1848 when a 3 ft. 7 inch tamping iron exploded up through Gage's skull. Gage recovered physically, but his personality was permanently altered by damage to his left frontal lobe. As a result of Gage's misfortune, the frontal lobes were identified as the seat of the personality.

temporal lobes

occipital lobes

parietal lobes

limbic system

image site author

Unlike the lobes of the neocortex, the limbic system has an evolutionarily primitive origin. The amygdala processes emotion, the hippocampus is central to emotional memory, and the caudate nucleus operates during execution of habitual movements.

hippocampus

amydala

neuron

The neuron is the basic operating unit of the central nervous system. Inter-neuronal information processing, involving complex neural networks, provides the nervous system with its enormous functional capacity. The human brain contains about 10^(11) neurons*, which connect, via synapses, with an average of 1000 other neurons. In total, the human brain may contain somewhere between 10^(14) and 10^(15) synaptic connections. Neurotransmitter chemicals effect the connection between neurons, when they cross the gap between neurons and interact with a specific receptor molecule. More than one hundred chemicals and a much larger number of receptors have been implicated in synaptic transmission. Some neurotransmitters are the targets of drug therapies. Receptor molecules are the targets of neurotoxic venomous substances.

* 10^(11) is equivalent to a 10 followed by 11 zeros = 1,000,000,000,000

For more information on neurons, neuroglial cells, and neurochemistry:
Main page of Neuron : action potential : axon : dendrite : dendritic spines : excitatory : inhibitory : integration : interneuron : metabotropic
neuron : synapse

Main page of Cell : cell membrane : endoplasmic reticulum : Golgi apparatus : ion channels : pinocytosis

Main page of BioChemistry : hydrophilic : hydrophobic :