The spelling of the word "extracellular signal" can be explained using IPA (International Phonetic Alphabet) phonetic transcription. The word is pronounced as /ˌɛkstrəˈsɛljələr ˈsɪɡnəl/, where the stress is on the second syllable of "extracellular" and on the first syllable of "signal." The "x" in "extracellular" is pronounced as /ks/, while the "c" in "cellular" is pronounced as /s/. Furthermore, the "g" in "signal" is pronounced as /ɡ/, not as /dʒ/. Overall, the correct spelling and pronunciation of this word are important in the scientific community.
Extracellular signal refers to a molecular or chemical cue that is released by a cell and acts upon neighboring or distant cells to transmit information or activate specific cellular responses. These signals play a crucial role in intercellular communication, coordinating various biological processes, and maintaining tissue homeostasis.
These signals can be diverse in nature and include hormones, growth factors, cytokines, neurotransmitters, and other molecules secreted by cells. They are usually produced by specialized cells and are released into the extracellular space, where they diffuse through the extracellular matrix or circulate within body fluids (such as blood or lymph).
Extracellular signals are essential for cellular processes such as cell differentiation, proliferation, migration, and apoptosis. Upon reaching their target cells, these signals bind to specific receptors on the cell surface or may be taken up by the cell through endocytosis. This binding triggers a cascade of intracellular events, activating various signaling pathways that lead to specific cellular responses.
These signals are involved in numerous physiological and pathological processes, including immune responses, tissue repair, embryonic development, and the progression of diseases such as cancer or neurodegenerative disorders. Understanding the mechanisms of extracellular signaling has significant implications for biomedical research, as its dysregulation can lead to various diseases or provide targets for therapeutic intervention.
The term "extracellular" derives from the Latin words "extra" meaning "outside" or "beyond", and "cellula" meaning "small room" or "cell". So "extracellular" literally refers to something outside the cell.
The word "signal" originates from the Old French term "signale" or "segnal" which means "a sign or flag", and further drawn from the Latin word "signum" meaning "mark, token, or signal". It originally referred to visual signs or flags used to communicate information.
When combined, the term "extracellular signal" refers to a signal or communication that occurs outside of a cell, often used in the context of cellular signaling pathways and intercellular communication.