Nerve supply to the skin the kind of sensory inputs which project to a specific region of the primary somatosensory cortex. Groups of nerve terminals located in the different layers of the skin are categorized depending on whether the skin is hairy, nonhairy, or an exposed mucous membrane. The hairy parts of the body such as the forearm or the leg have two groups of nerve endings: those that end along with the hair follicles, and also with the arborizations of unmyelinated axons which are referred to as “free” nerve endings because they are served by both myelinated and unmyelinated axons. Nonhairy skin, such as
Gastric pits Gastric pits Gastric pits are indentations in the stomach which denote entrances to 3-5 tubular shaped gastric glands. They are deeper in the pylorus than they are in the other parts of the stomach. The human stomach has several million of these pits which dot the surface of the lining epithelium. Surface mucous cells line the pits themselves but give way to a series of other types of cells which then line the glands themselves. Gastric juice is secreted from gastric glands, which are located in narrow tube like structures called gastric pits. Gastric juice contains hydrochloric acid, pepsinogen and