CORTICAL REACTION Meaning and
Definition
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The cortical reaction refers to a series of biochemical events that occur in the cortex, or outer layer, of an egg following fertilization. It is a crucial mechanism that plays a key role in preventing polyspermy, the fertilization of an egg by more than one sperm.
Upon fertilization, the sperm enters the egg and triggers a release of intracellular calcium ions (Ca2+) in the egg cytoplasm. This calcium wave propagates towards the periphery of the egg, ultimately reaching the cortical region. The rise in cytoplasmic calcium levels triggers the cortical reaction.
The cortical reaction involves the exocytosis of cortical granules, which are storage vesicles located just beneath the egg's plasma membrane. These granules are released into the extracellular space surrounding the egg. The contents of the cortical granules, including enzymes and other factors, are then dispersed into this space.
The released enzymes modify the zona pellucida, a glycoprotein layer surrounding the egg, making it impenetrable to additional sperm. The enzymes cause the zona pellucida to harden, thereby creating a physical barrier that prevents polyspermy from occurring.
This physiological process is vital for successful embryo development, as the fusion of multiple sperm with an egg would likely lead to abnormal or nonviable embryos. Consequently, the cortical reaction ensures genetic integrity and contributes to the reproductive success of organisms.
Common Misspellings for CORTICAL REACTION
- xortical reaction
- vortical reaction
- fortical reaction
- dortical reaction
- cirtical reaction
- ckrtical reaction
- clrtical reaction
- cprtical reaction
- c0rtical reaction
- c9rtical reaction
- coetical reaction
- codtical reaction
- coftical reaction
- cottical reaction
- co5tical reaction
- co4tical reaction
- corrical reaction
- corfical reaction
- corgical reaction
- coryical reaction
Etymology of CORTICAL REACTION
The word "cortical" in "cortical reaction" can be traced back to the Latin word "cortex", which means "bark" or "rind". It was later adopted into the medical vocabulary to refer to the outer layer of an organ, particularly in the context of the brain.
The term "cortical reaction" was coined in the field of developmental biology and refers to a process that occurs during fertilization in certain organisms. It is called a "reaction" because it involves a series of changes that take place in the outer layer (cortex) of the egg upon fertilization.
In this context, the cortical reaction involves the release of cortical granules from the cortex of the egg. These granules contain enzymes that modify the outer coating of the egg, preventing additional sperm from penetrating and fertilizing the egg.
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