Chapter 4 Skin and Body Membranes

Hair Follicle

A a small secretory cavity, sac, or gland, from which a hair grows and into which the sebaceous (oil) glands, that secrete the oily and waxy substance called sebum, opens. (Sebum waterproofs and lubricates the skin and hair of mammals). The follicle is lined by cells derived from the epidermal (outside) layer of the skin.

Papillary

Most common form of well-differentiated thyroid cancer, papillary carcinoma appears as an irregular solid or cystic mass or nodule in a normal thyroid parenchyma.

Ruffini Corpuscle

Nerve Endings. In addition to touch, pressure, and vibration, there are mechanoreceptors responsible for the sensation of the stretch of your skin, sustained pressure on the skin, and the perception of heat.

sweat gland

The eccrine sweat gland, which is controlled by the sympathetic nervous system, regulates body temperature. When internal temperature rises, the eccrine glands secrete water to the skin surface, where heat is removed by evaporation.

Shaft

The midsection of a long bone; the dialysis.

Vernix Caseosa

a greasy deposit covering the skin of a baby at birth. it is waxy and sometimes compared to cheese and is white. It is produced by cells and has a protective role during the development of the baby.

Cuticle

a protective and waxy or hard layer covering the epidermis of a plant, invertebrate, or shell. Which could also be the outer cellular layer of hair, it locks the hair into its follicle.

Meissner's Corpuscle

a sensory nerve ending that is sensitive to mechanical stimuli, found in the dermis in various parts of the body.

Arrector Pili muscle

a small muscle attached to hair follicles in mammals. Contraction of these muscles causes the hairs to stand on end, known as goose bumps. Pressure exerted by the muscle may cause sebum to be forced along the hair follicle towards the surface, protecting the hair

Root

a tubular outgrowth of a trichoblast, a hair-forming cell on the epidermis what holds the hair in place under the skin.

Merkel cells

also known as Merkel-Ranvier cells or tactile epithelial cells, are oval-shaped mechanoreceptors essential for light touch sensation and found in the skin of vertebrates.

Adipose Tissue

also known as fat. It is an anatomical term for loose connective tissue composed of adipocytes, which are cells that primarily make up adipose tissue. Its main function is to store energy in the form of fat, but it also cushions and insulates the body.

Pancinian Corpuscle

an encapsulated ending of a sensory nerve that acts as a receptor for pressure and vibration.

Second

an intracellular substance that mediates cell activity by releasing a signal from an extracellular molecule bound o the cell's surface.

Oil (sebum)

are microscopic exocrine glands in the skin that secrete an oily or waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals.

Epithelial membrane, Connective membrane

consists of a continuous sheet of cells, one or more layers thick, which is attached to the underlying connective tissue by a basement membrane.

Synovial membrane

is a specialized connective tissue that lines the inner surface of capsules of synovial joints and tendon sheath. It makes direct contact with the synovial fluid lubricant, which it is primarily responsible for maintaining.

Lamina Propria

is a thin layer of loose areolar connective tissue, which lies beneath the epithelium and together with the epithelium and basement membrane constitutes the mucosa.

Lucidum

is a thin, clear layer of dead skin cells in the epidermis named for its translucent appearance under a microscope. It is readily visible by light microscopy only in areas of thick skin, which are found on the palms of the hands and the soles of the feet.

Whorled Ridges

one of the three types of fingertips. It forms a spiral made up of cells on your finger tip. Fun Fact: a person that possesses this on their thumb tends to be a leader and does not make a good follower.

Lunula

or lunulae is the crescent-shaped whitish area of the bed of a fingernail or toenail. The lunula is the visible part of the root of the nail.

Epithelial, Connective

relating to the thin tissue forming the outer layer of a body's surface and lining hollow structures. It is a tissue that connects, supports, binds, or separates other tissues or organs, typically having a few cells in an amorphous matrix, often with collagen or other fibers, and including cartilaginous, fatty, and elastic tissues.

Visceral

relating to the viscera.the internal organs in the main cavities of the body, especially those in the abdomen, e.g., the intestines.

Arrector pili

small muscles attached to hair follicles in mammals, contraction of these muscles causes the hairs to stand on end, also known as goose bumps.

Reticular Layer

the lower layer of the dermis, found under the papillary dermis, composed of dense irregular connective tissue featuring densely packed collagen fibers