Panniculus carnosus is a term used in anatomy to refer to the layer of muscle tissue found under the subcutaneous fat layer in certain animals. The pronunciation of this term can be confusing, as the spelling does not make it clear which syllable should be stressed. However, using the International Phonetic Alphabet (IPA), it can be transcribed as /pænɪkjuːləs kɑːrˈnoʊsəs/. This indicates that the stress should be on the second syllable of 'panniculus' and the first syllable of 'carnosus.'
Panniculus carnosus refers to a specialized layer of muscle found in certain animals, primarily mammals, that is located beneath the skin. Also known as the "subcutaneous muscle layer," the panniculus carnosus is composed of thin, flat muscle fibers that are attached to the underside of the skin and run parallel to its surface. This muscular structure can be voluntarily or involuntarily contracted and relaxed, allowing for various functions depending on the species.
In some animals, such as certain small mammals like rats or rabbits, the panniculus carnosus is well-developed and serves multiple purposes. It plays a crucial role in regulating body temperature by involuntarily contracting to generate heat or dilating to eliminate excess heat through the skin's surface. Additionally, the panniculus carnosus allows for quicker and precise control of body movements by contracting and adjusting the skin accordingly, facilitating actions like burrowing, climbing, or escaping predators.
However, in many larger mammals, including humans, the panniculus carnosus is rudimentary and largely non-functional. It has evolved over time to become reduced and less developed, losing its primary functions and becoming vestigial. In humans, remnants of the panniculus carnosus can be observed in the presence of certain reflexes, such as the goosebumps or piloerection response triggered by cold or emotional arousal. Despite its diminished role, the panniculus carnosus remains an intriguing anatomical feature that provides insights into the evolutionary history of mammals.
A thin layer of muscular tissue, beneath or in the substance of the superficial fascia, such as the musculus platysma myoides.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
The word "panniculus carnosus" comes from Latin.
- "Panniculus" is derived from "pannus", which means "cloth" or "rag". In this context, it refers to a small piece of cloth or a covering.
- "Carnosus" is derived from "carnis", which means "flesh" or "meat". It indicates something related to or resembling flesh.
When combined, "panniculus carnosus" refers to a thin layer of striated (voluntary) muscle found in some mammals, particularly rodents and marsupials. This term is used to describe a slice of muscle that is attached to the skin and can make the skin move or twitch independently.