In psychoanalytic theory, it is concerned with the emotional investment of the self (self-esteem). It is generally held that individuals whose self-esteem is chronically low have not experienced sufficient love and appreciation in their early development and are therefore unable to experience genuine deep feelings toward others, and constantly struggle with doubts about their own …
Author Archives: Brian Hopkins
N170
A specific component of the event-related potential (ERP), elicited by upright faces, and observed in adults but not infants, and thus considered to be a neural marker of specialized mechanisms for face processing. In most individuals it is lateralized in the right hemisphere. Meanwhile the component is maximal over occipito-temporal electrode sites, which indicates its source is …
Myotube
The basic multinucleate muscle cell that is tubular in appearance, and which is a developing skeletal muscle. In the past, it was questioned whether myotubes were formed from the fusion of multiple, proliferating myoblasts that exit the cell cycle, or from a single myoblast that undergoes nuclear division without cytokinesis. It is now seems to …
Myosin
A family of contractile proteins, present in striated muscle and most eukaryotic cells that combines with actin to form actomyosin, and which in striated muscle gives the A-bands their dark color. This is myosin II (a two-headed, tailed variety). Myosin I (a single-headed, tailless variety) is involved in cell locomotion. Myosin moves actin filaments …
Myotome
Alsocalled the muscle plate, it is the middle portion of the (mesodermic) somitefrom which skeletal muscle develops. More specifically, it is a group ofmuscles innervated by muscle fibers nerve root. In contrast, a dermatomeis a skin area innervated by sensory fibers of a single nerve root. Knowledge of the location of mytomes and dermatomes is used …
Myoglobin
A single-chain, iron-containing protein of 153 amino acids found in cardiac and striated muscle fibers, structurally similar to a single sub-unit of hemoglobin and having a higher affinity for oxygen than hemoglobin of the blood. It makes oxygen available to the muscles for contraction, and it gives up oxygen only under anoxic conditions. When muscle …
Myofibrils and myofilaments
The structural unit of striated muscle, with several found in each fiber. They are, in fact, long, contractile cells with many nuclei, of which striated muscle is formed. the structural unit of striatedmuscle, a basic rod-like unit, several being found in each fiber, themyofibrils are made up of thick (composed mainly of the protein myosin) andthin …
Myoblast
A cell that develops into a muscle fiber. Myoblasts respond to the fibroblast growth factor (FGF) by synthesising DNA and undergoing mitosis. They fuse to form myotubes. . See DNA (deoxyribonucleic acid), Fibroblast growth factor (FGF), Mitosis, Muscle fiber, Myofilaments, Myotube
Myelination
The process of myelin elaboration that covers, insulates and promotes rapid signal conduction in axons and which is principally a postnatal event in humans. In the human brain, myelination continues at least through the first decade of life, with some phylogenetically recent structures like the frontal cortex only appearing fully myelinated in the second decade. …
Myelin
The sheath of fatty tissue composed of 70-80% lipid and 20-30% protein, derived from glial cells, that wraps around the axons of neurons in the central and peripheral nervous system, whose purpose is to increase transmission speed and reliability. The combined length of myelinated nerve fibers in the adult brain has been estimated to achieve …