Histologic Classification of IgA Nephropathy: Past, Present, and Future

The stomach comprises several layers that work together to facilitate digestion and protect the organ. The outermost layer is called the serosa, which provides support and protection to the stomach. The muscularis externa layer is responsible for the mechanical breakdown of food by contracting and moving the stomach. The submucosa layer, located beneath the muscularis externa, contains connective tissue, blood vessels, nerves, and glands that secrete mucus and other substances essential for...

The microscopic anatomy of the liver is a complex and intricate system that comprises numerous structural units known as liver lobules, each of which is comparable in size to a sesame seed. These hexagonal structures consist of plates of liver cells or hepatocytes, which are characterized by their versatility and abundance of cellular apparatus like rough and smooth ER, Golgi apparatus, peroxisomes, and mitochondria.
Hepatocytes perform a variety of essential functions. They secrete...

The large intestine, a vital component of the gastrointestinal tract, is structured with four main layers: the mucosa, submucosa, muscularis, and serosa. Each layer performs a distinct role in facilitating the smooth functioning of the large intestine.
The innermost mucosa layer comprises simple columnar epithelium, lamina propria, and muscularis mucosae. This layer is primarily populated with absorptive cells, tasked with water absorption, and goblet cells, responsible for secreting mucus to...

The small intestine exhibits a unique histological structure that significantly enhances its function in digestion and nutrient absorption. These structures include circular folds, villi, and various specialized cells that collectively facilitate the digestion of food.
The intestinal lining features transverse folds called circular folds, each housing fingerlike projections known as intestinal villi. These villi are covered by a layer of simple columnar epithelium, also referred to as...

A tough, fibrous membrane, the tunica albuginea, covers the testes, extending inward to form fibrous partitions or septa, dividing them into internal compartments called lobules. Each lobule has 1 to 3 tightly coiled seminiferous tubules where sperm production occurs. These tubules merge into a tubular network at the back of the testis, known as the rete testis. It connects to 15 to 20 efferent ductules, leading to the epididymis.
The spermatogenic cells, responsible for producing sperm, are...

The uterine wall consists of three histological layers: the perimetrium, myometrium, and endometrium. The outermost perimetrium is a thin, serous membrane connected with the broad ligament on the sides, which helps anchor the uterus in the pelvic cavity. The thickest layer, myometrium, is mainly made up of smooth muscle tissue bundles. Its contractions are vital in facilitating the expulsion of the uterine lining, fetus, and placenta during menstruation and childbirth.
The endometrium is the...