Self And The Phenomenon Of Life: A Biologist Examines Life From Molecules To Humanity

354 Self and the Phenomenon of Life

b2726 Self and the Phenomenon of Life: A Biologist Examines Life from Molecules to Humanity “9x6”

Dendritic cells: Immune cells that present antigenic peptides from pathogens

to the T lymphocytes, thereby activating the latter into a killer cell. (Unre-

lated to dendrites of neurons)

Dendritic spine: Small protrusions on the neuronal dendrites that serve as

the post-synaptic component of a synapse. The number of dendritic spines

increases with learning.

DNA (Deoxyribonucleic acid): A macromolecule made up of deoxy-ribose

sugar, phosphate, and the nucleobases, containing information for inheri-

tance and for the making of proteins.

EEG: see Electro-encephalogram.

Electro-encephalogram: Recording of brain electrical activity through the

scalp.

Electron transport chain: A series of steps taking place along the mitochon-

drial membrane, creating a proton gradient across the membrane. The

inward flow of protons at the end of the process provides energy for the

synthesis of ATP from ADP.

Entorhinal cortex: The part of the temporal lobe of the brain that provides

input and output information to the hippocampus.

Entropy: A measure of disorder derived from the second law of thermo-

dynamics. See “Second law.”

Epigenetics: Heritable characteristics of an organism that is not specified in

the nucleotide sequence of DNA.

Eusocialism: The instinctive formation of a large social group in insects.

Evolution: Changes in a species across generations. Darwin’s theory posits that

the underlying mechanism of evolution is the interaction of the heritable

variable traits of an organism and the restriction imposed by the environ-

ment (natural selection).

Exteroception: Sensation of the stimuli from the outside world, as opposed to

those from one’s own body.

Functional MRI (fMRI): A method of MRI that detects increase in activ-

ity in brain regions through observation of increase in blood flow; useful

for correlating brain structures with cognitive function. (See also “magnetic

resonance imaging” and “MRI”)

Ganglion: In neuro-anatomy, an aggregate of neuronal cell bodies. If located

deep inside the brain, it is also called a “nucleus.”

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