Search results
Results from the WOW.Com Content Network
Presbycusis is the second most common illness next to arthritis in aged people. Many vertebrates such as fish, birds and amphibians do not experience presbycusis in old age as they are able to regenerate their cochlear sensory cells, whereas mammals including humans have genetically lost this regenerative ability.
Cellular atrophy is a decrease in cell size. If enough cells in an organ undergo atrophy the entire organ will decrease in size. Thymus atrophy during early human development (childhood) is an example of physiologic atrophy. Skeletal muscle atrophy is a common pathologic adaptation to skeletal muscle disuse (commonly called "disuse atrophy").
Cell growth refers to an increase in the total mass of a cell, including both cytoplasmic, nuclear and organelle volume. [1] Cell growth occurs when the overall rate of cellular biosynthesis (production of biomolecules or anabolism) is greater than the overall rate of cellular degradation (the destruction of biomolecules via the proteasome, lysosome or autophagy, or catabolism).
Microscopically, cells resemble normal cells but are increased in numbers. Sometimes cells may also be increased in size (hypertrophy). [7] Hyperplasia is different from hypertrophy in that the adaptive cell change in hypertrophy is an increase in the size of cells, whereas hyperplasia involves an increase in the number of cells. [8]
Based on stochastic gene expression, cellular differentiation is the result of a Darwinian selective process occurring among cells. In this frame, protein and gene networks are the result of cellular processes and not their cause. [citation needed] An overview of major signal transduction pathways.
Cell proliferation requires both cell growth and cell division to occur at the same time, such that the average size of cells remains constant in the population. Cell division can occur without cell growth, producing many progressively smaller cells (as in cleavage of the zygote ), while cell growth can occur without cell division to produce a ...
LH calls on the Leydig cells (also in the testes) to make testosterone. Testosterone production can be compromised if something happens to one of the main players in this process — the ...
Cell division is the process by which a parent cell divides into two daughter cells. [1] Cell division usually occurs as part of a larger cell cycle in which the cell grows and replicates its chromosome(s) before dividing.