Langerhans cells

Examples of Langerhans cells in the following topics:

• Types of Cells in the Pancreas

  • The islets of Langerhans are the regions of the pancreas that contain many endocrine (i.e., hormone-producing) cells.
  • The lightly-staining clusters of cells are called islets of Langerhans, which produce hormones that underlie the endocrine functions of the pancreas.
  • Alpha cells- the alpha cells produce glucagon, and make up 15–20% of total islet cells.
  • The islets of Langerhans can influence each other through paracrine and autocrine communication.
  • A porcine islet of Langerhans.

• Dendritic Cells

  • Dendritic cells are immune cells that function to process antigens and present them to T cells.
  • Langerhans cells of the epidermis) are located in main portals of entry of microbes (skin and gut epithelia).
  • Mature dendritic cells reside in the T cell zones of the lymph nodes, and in this location they display antigens to T cells.
  • Dendritic cells are constantly in communication with other cells in the body.
  • This communication can take the form of direct cell-to-cell contact based on the interaction of cell-surface proteins.

• Histology of the Pancreas

  • The pancreas serves digestive and endocrine functions, and it is composed of two types of tissue: islets of Langerhans and acini.
  • Lightly-staining clusters of cells are called islets of Langerhans.
  • The part of the pancreas with endocrine function is made up of approximately a million cell clusters called islets of Langerhans.
  • Four main cell types exist in the islets.
  • They are relatively difficult to distinguish using standard staining techniques, but they can be classified by their secretion: α cells secrete glucagon (increase glucose in blood), β cells secrete insulin (decrease glucose in blood), delta cells secrete somatostatin (regulates/stops α and β cells), and PP cells or gamma cells, secrete pancreatic polypeptide.

• Overview of Pancreatic Islets

  • Pancreatic islets, or the islets of Langerhans, are regions of the pancreas that contain its endocrine, or, hormone-producing, cells.
  • The endocrine function of the pancreas is involved in maintaining blood glucose levels, and the structures involved are known as the pancreatic islets, or, islets of Langerhans.
  • Alpha cells- the alpha cells produce glucagon, and make up 15–20% of total islet cells.
  • Insulin activates beta cells and inhibits alpha cells, while glucagon activates alpha cells, which activates beta cells and delta cells.
  • The islets of Langerhans are the regions of the pancreas that contain its endocrine ( hormone-producing) cells.

• Protection

  • The skin is composed of tough skin cells as well as a tough protein called keratin that guard tissues, organs, and structures underneath the skin against physical damage from minor cuts, scratches, and abrasions.
  • The skin also contains important cells called Langerhans cells. 
  • These cells help our immune system fight off infectious biological agents, like bacteria that try to get further into our body through skin that may have been compromised by physical damage. 

• Pancreas

  • The part of the pancreas with endocrine function is made up of approximately a million cell clusters called islets of Langerhans.
  • Four main cell types exist in the islets.
  • They are relatively difficult to distinguish using standard staining techniques, but they can be classified by their secretion: α cells secrete glucagon (increase glucose in blood), β cells secrete insulin (decrease glucose in blood), delta cells secrete somatostatin (regulates/stops α and β cells), and PP cells or gamma cells, secrete pancreatic polypeptide.
  • Nourse, the islets are "busily manufacturing their hormone and generally disregarding the pancreatic cells all around them, as though they were located in some completely different part of the body. " The islet of Langerhans plays an imperative role in glucose metabolism and regulation of blood glucose concentration.
  • In humans, the secretory activity of the pancreas is regulated directly via the effect of hormones in the blood on the islets of Langerhans and indirectly through the effect of the autonomic nervous system on the blood flow.

• Pancreas

  • It contains both exocrine cells that excrete digestive enzymes and endocrine cells that release hormones.
  • The endocrine cells of the pancreas form clusters called pancreatic islets or the islets of Langerhans .
  • The pancreatic islets contain two primary cell types: alpha cells, which produce the hormone glucagon, and beta cells, which produce the hormone insulin.
  • The islets of Langerhans are clusters of endocrine cells found in the pancreas; they stain lighter than surrounding cells.
  • The alpha and beta cells produce glucagon and insulin, respectively.

• Structure of the Skin: Epidermis

  • The newly produced cells push older cells into the upper layers of the epidermis with time. 
  • From the stratum basale, the keratinocytes move into the stratum spinosum, a layer so called because its cells are spiny-shaped cells. 
  • They are dead skin cells filled with the tough protein keratin. 
  • The epidermis is made up of 95% keratinocytes but also contains melanocytes, Langerhans cells, Merkel cells, and inflammatory cells.
  • The stratum basale is primarily made up of basal keratinocyte cells, which can be considered the stem cells of the epidermis.

• Cells and Organs of the Immune System

  • The thymus "educates" T cells and provides an inductive environment for the development of T cells from hematopoietic progenitor cells.
  • Langerhans cells in the skin are part of the adaptive immune system.
  • Natural killer cells are leukocytes that attack and destroy tumor cells, or cells that have been infected by viruses.
  • B cells and T cells are the major types of lymphocytes and are derived from hematopoietic stem cells in the bone marrow.
  • These cells have no cytotoxic activity and do not kill infected cells or clear pathogens directly.

• Interactions of Hormones at Target Cells

  • For example, thyroid hormone increases the number of receptors available for epinephrine at the latter's target cell, thereby increasing epinephrine's effect at that cell.
  • Bundles of cells in the pancreas, called the islets of Langerhans, contain two kinds of cells, alpha cells and beta cells.
  • Beta cells secrete insulin.
  • Liver and muscle cells convert glucose to glycogen, for short term storage, and adipose cells convert glucose to fat.
  • Alpha cells secrete glucagon.