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| Subcutaneous Fat |
Subcutaneous Fat
Subcutaneous fat is the layer of fat located just under the skin. It acts as a cushion to protect muscles and bones, helps regulate body temperature, and serves as an energy reserve. While some subcutaneous fat is essential for health, excessive amounts can contribute to obesity and related health issues.
Patients frequently have subcutaneous fat as a presenting problem, and its thickness varies depending on the patient's weight and body habits. The distribution of fat can vary laterally throughout the platysma's surface, with patients often exhibiting the highest amount anteromedially. With its base at the mandibular line and its peak at the hyoid, fat often has a triangle shape and is most prevalent in the submental region. The deep extension that occurs when the platysma muscles spontaneously split on their medial sides is often continuous with the subplatysmal fat.
Because it lacks septations and fibrous linkages, this fat can be more readily molded using open or closed techniques like liposuction and direct excision.
Prominent jowls or melolabial folds that drop from the face might form in the same subcutaneous plane. Their existence significantly affects the perception of a young, attractive neck, even though they are not neck structures.
The preoperative examination and the patient's conversation should take these structures into account, since they might be concurrently treated during neck rejuvenation. In order to get a more acute CMA and create the desired shape, the majority of surgical changes aim to decrease the bulk of fat in this region. Among the most popular methods are submental liposuction and direct excision.
Structure and Function of the Skin
Subcutaneous Body Fat
It acts as a buffer against cold, protects deep tissues from blunt damage, and provides the body with a store of energy. Obese children and adolescents with peripheral insulin resistance exhibit metabolic abnormalities, indicating that biologically active fat cells are involved in hormone transmission.
Subcutaneous fat:
- Insulates
- Takes in injuries
- Serves as a backup energy source
- Has biological activity
SUBCUTANEOUS FAT
The subcutaneous fat is mostly made up of lipocytes and is located directly under the dermis. It is a crucial source of energy and hormone metabolism, a heat insulator, and a shock cushion. Due to their underdeveloped subcutaneous tissues, premature babies are more susceptible to metabolic problems and thermal instability.
Roux-en-Y gastric bypass.
Fat beneath the skin
Additionally, people with obesity have much larger subcutaneous fat mass. Subcutaneous adipose tissue is hormonally active and contributes to the pathophysiologic alterations that occur in fat, even though it is not as harmful to end-organ function as visceral fat.
Several studies that have attempted to assess the involvement of subcutaneous fat in cardiometabolic illness have found that subcutaneous fat has lower amounts of bioactive inflammatory markers than visceral fat. As a result, subcutaneous fat is not believed to be as harmful to obese people.
To find out if removing a significant amount of subcutaneous fat was linked to cardiometabolic benefits, several trials examined the effects of panniculectomy performed either during or after RYGB. There is no data demonstrating a metabolic advantage directly linked to panniculectomy, despite the fact that patients who had contemporaneous or subsequent panniculectomy had improvements in cosmetic and quality of life outcomes. The idea that visceral fat is more hormonally active and significant in the emergence of metabolic syndrome and its subsequent resolution with reduced visceral fat following RYGB is supported by this.
Further research has shown that removing subcutaneous fat alone raises adiponectin levels. Subcutaneous fat removal surgeries that show statistically significant short-term improvements in HDL cholesterol, adiponectin, and fasting glucose levels include mammoplasty and abdominoplasty. Although these trials did not examine variations in parameters depending on body mass index, subcutaneous fat removal techniques have not been demonstrated to alleviate obesity-related comorbidities. Nevertheless, our findings show that subcutaneous fat is still hormonally active and contributes to the accumulation of visceral and ectopic fat in obesity.
Emergency Department Wound Management
The subcutaneous tissue
Subcutaneous tissue is mostly composed of mature subcutaneous fat. Thin, fibrous septae divide the lobules that make up the subcutaneous layer, and it is through them that lymphatics and arteries pass. The subcutis is stabilized by the septae, which also compartmentalize it and link the fascial planes under the subcutaneous fat to the reticular layer of the dermis. This layer varies in thickness across individuals and anatomical locations.
Panniculitis
In terms of both structure and function, subcutaneous tissue is widely distributed throughout the body and constitutes a real organ.4 Energy provision, insulation, temperature control, and defense against mechanical harm all depend on this tissue.
In a healthy person, subcutaneous fat makes up around 10% of body weight. According to Ackerman5, the main microlobule, which is made up of a tiny collection of adipocytes or lipocytes and has a diameter of around 1 mm, is the fundamental unit of subcutaneous fat.
When primary microlobules group together, they become secondary lobules, which have a diameter of around 1 cm and are encircled by thin connective tissue septa. By creating compartments, the septa provide the subcutaneous tissue stability.
Every part of the body has a distinct thickness of subcutaneous fat; the hypodermis is greater in the hips and buttocks, while the subcutis is smaller in the scrotum and eyelids. In addition, the distribution of subcutaneous fat varies by gender, and the female torso, hips, pubis, and thighs have rounder shapes due to higher subcutis thickness. Adipocytes from various locations inside the same person exhibit varying levels of metabolic activity, which is the evidence underlying the morphologic heterogeneity of subcutaneous fat.
Originating from mesenchymal stem cells, adipocytes are a specific type of connective tissue that can synthesize and store fat. They show as empty cells with a signet-ring shape when stained with hematoxylin-eosin. This is because, in regularly treated specimens, the lipid content dissolves, and a single, sizable intracytoplasmic vacuole that contains fat displaces the flat spindle nucleus at the cell's periphery. The adipocytes must be shown in their entirety using frozen sections or other methods.
Autologous Fat Augmentation for Addressing Facial Volume Loss
In contrast to the recipient site's comparatively avascular subcutaneous fat, the muscle and fascia layers have a more abundant vascular supply, which may improve the survival of fat transplants. Using a rat model, Guerrerosantos et al. showed that transplanted fat, either in the form of thin rolls or strips, fared best when injected into or near muscle. No long-term retention of the grafts was observed in the research groups where the fat was administered subcutaneously.
Débridement
The components of subcutaneous tissue include nerves, veins, and fat. In other cases, bleeding near the border of the tissue is not a good signal because of the lower concentration of blood vessels in the subcutaneous fat. Healthy fat is supple, robust, and has a beautiful yellow appearance. In addition to being rigid and nonpliable, dead fat displays a gray pallor.
Debridement is necessary until the fat is mushy, yellow, and normal-looking. Because undermining jeopardizes the viability of the skin that lies on top, it should be avoided. Maintaining the fat in a wet environment following débridement is crucial to preventing desiccation.
Facial Aging and Anatomy of the Facial Nerve
The subcutaneous tissue contains distinct compartments of fat and fibrous material that are not homogenous. They have names like "malar fat pad" and "nasolabial fat" because of the predominance of the subcutaneous fat in certain areas. The retention ligaments, which integrate into the dermis after passing superficially, are located at the boundary of these subcutaneous compartments.
In young people, compartment transitions are seamless and imperceptible. A sequence of concavities and convexities that form these compartments forms with age. Many explanations have been proposed for these alterations, such as selective atrophy and hypertrophy, fat descent,
The malpositioning of fat compartments is caused by the weakening of the ligaments. It is now clear, however, that fat decreases very little with age. The holding ligaments keep the fat in its proper location by compartmentalizing it.
Reference:
https://www.sciencedirect.com/topics/medicine-and-dentistry/subcutaneous-fat
