The preputial mucosa of the

penis A penis (; : penises or penes) is a sex organ through which male and hermaphrodite animals expel semen during copulation (zoology), copulation, and through which male placental mammals and marsupials also Urination, urinate. The term ''pen ...

is the

epithelium Epithelium or epithelial tissue is a thin, continuous, protective layer of cells with little extracellular matrix. An example is the epidermis, the outermost layer of the skin. Epithelial ( mesothelial) tissues line the outer surfaces of man ...

of the inside of the prepuce, or

foreskin In male Human body, human anatomy, the foreskin, also known as the prepuce (), is the double-layered fold of Human skin, skin, Mucous membrane, mucosal and Muscle tissue, muscular tissue at the distal end of the human penis that covers the glans ...

. To differentiate it from the cutaneous

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different ...

of the outside of the prepuce, it is sometimes referred to as the inner mucosa. It starts at the ridged band of the prepuce and continues to the coronal sulcus (groove behind the

glans penis In male human anatomy, the glans penis or penile glans, commonly referred to as the glans, (; from Latin ''glans'' meaning "acorn") is the bulbous structure at the Anatomical terms of location#Proximal and distal, distal end of the human penis ...

), where it meets the epithelium of the glans and penile shaft. The preputial mucosa is devoid of hair, as is the cutaneous surface. Weiss ''et al''. (1993) report the preputial mucosa contains fewer

Langerhans cell A Langerhans cell (LC) is a tissue-resident macrophage of the skin once thought to be a resident dendritic cell. These cells contain organelles called Birbeck granules. They are present in all layers of the epidermis and are most prominent in t ...

s than most mucosal epithelia. These cells secrete

cytokine Cytokines () are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are produced by a broad range of cells, including immune cells like macrophages, B cell, B lymphocytes, T cell, T lymphocytes ...

s (a non-

antibody An antibody (Ab) or immunoglobulin (Ig) is a large, Y-shaped protein belonging to the immunoglobulin superfamily which is used by the immune system to identify and neutralize antigens such as pathogenic bacteria, bacteria and viruses, includin ...

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

that generates an

immune response An immune response is a physiological reaction which occurs within an organism in the context of inflammation for the purpose of defending against exogenous factors. These include a wide variety of different toxins, viruses, intra- and extracellula ...

on contact with specific

antigens In immunology, an antigen (Ag) is a molecule, moiety, foreign particulate matter, or an allergen, such as pollen, that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. An ...

), and are an essential part of the

immune system The immune system is a network of biological systems that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to bacteria, as well as Tumor immunology, cancer cells, Parasitic worm, parasitic ...

. Fleiss ''et al''. (1998) point out that Weiss ''et al''. (1993) studied foreskins of neonates and their findings may not be applicable to adults. De Witte ''et al''. (2007) report that Langerhans cells produce Langerin. Langerin inhibits the infection of T-cells with

HIV-1 The subtypes of HIV include two main subtypes, known as HIV type 1 (HIV-1) and HIV type 2 (HIV-2). These subtypes have distinct genetic differences and are associated with different epidemiological patterns and clinical characteristics. HIV-1 e ...

. Dinh ''et al''. (2012) compared the depth of the

keratin Keratin () is one of a family of structural fibrous proteins also known as ''scleroproteins''. It is the key structural material making up Scale (anatomy), scales, hair, Nail (anatomy), nails, feathers, horn (anatomy), horns, claws, Hoof, hoove ...

layer of the inner foreskin with the depth of the keratin layer outer foreskin in foreskins of healthy Ugandan males who had been circumcised. The researchers concluded that, "despite inter- and intra-individual variability, keratin thickness was similar in the inner and outer foreskin of healthy Ugandan men, and that reduced keratin thickness is not likely to make the inner foreskin more susceptible to HIV acquisition." Fleiss ''et al''. (1998) report the inner mucosa contains apocrine glands, which secrete cathepsin B,

lysozyme Lysozyme (, muramidase, ''N''-acetylmuramide glycanhydrolase; systematic name peptidoglycan ''N''-acetylmuramoylhydrolase) is an antimicrobial enzyme produced by animals that forms part of the innate immune system. It is a glycoside hydrolase ...

, chymotrypsin, neutrophil elastase, and

hormones A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs or tissues by complex biological processes to regulate physiology and behavior. Hormones a ...

such as androsterone. The first four substances have protective immunological functions. This view is currently controversial and a

histological Histology, also known as microscopic anatomy or microanatomy, is the branch of biology that studies the microscopic anatomy of biological tissue (biology), tissues. Histology is the microscopic counterpart to gross anatomy, which looks at large ...

study reported that the mucosal surface of the prepuce is completely free of lanugo hair follicles, apocrine (

sweat Perspiration, also known as sweat, is the fluid secreted by sweat glands in the skin of mammals. Two types of sweat glands can be found in humans: eccrine glands and Apocrine sweat gland, apocrine glands. The eccrine sweat glands are distribu ...

) and sebaceous glands.

References

Further reading