Accessory structures of the skin – Flashcards

Develop from the epidermis of an embryo - hair, glands, and nails - perform vital functions.

Protect the body

Left gland

Right gland

Help regulate body temperature

Pili

Present on most skin surfaces except the palms, palmar surfaces of the fingers, soles, and plantar surfaces of the toes. Usually most heavily distributed across the scalp, over the brows of the eyes, and around the external genitalia.

Guards the scalp from injury and the sun's rays.

Protect the eyes from foreign particles.

Protect against inhaling insects and foreign particles.

A thread of fused, dead, keratinized epidermal cells that consists of a shaft and a root.

The superficial portion of hair that projects above the surface of the skin.

The portion of hair below the surface that penetrates into the dermis and sometimes into the subcutaneous layer.

Surrounding the hair roots.

Composed of two layers of epidermal cells, external and internal root sheaths, surrounded by a connective tissue sheath.

Surrounding each hair follicle are these nerve endings that are sensitive to touch. If a hair shaft is moved, this responds.

The base of each hair follicle is enlarged into this onion shaped structure. Includes papilla of the hair and the hair matrix.

A nipple shape indentation in the hair bulb. It contains many blood vessels and provides nourishment for the growing hair.

A region in the bulb of the hair which produces new hairs by cell division when older hair is shed.

The treatment of disease, usually cancer, by means of chemical substances or drugs. Interrupts the life-cycle of rapidly dividing cancer cells and also affects other rapidly dividing cells in the body, such as the hair matrix cells in the process.

Smooth muscle associated with hair. Extends from the epidermis to the side of the hair follicle. Under stress, nerve endings stimulate the muscle to contract which pulls the hair shaft perpendicular to the skin surface [goosebumps].

Due to melanin. Synthesized by melanocytes in the matrix of the bulb and passes into cells of the root and shaft.

Contains mostly brown to black melanin.

Contains variance of yellow to red melanin in which there is iron and more sulfur.

Occurs with a decline in the synthesis of melanin.

Results from accumulation of air bubbles in the hair shaft.

Masculinizing sex hormones. At puberty cause males to develop a typical male pattern of hair growth including a beard and a hairy chest. In females a smaller quantity promotes hair growth in the axillae and pubic region.

Occasionally, a tumor of the adrenal glands, testes or ovaries produces an excessive amount of androgens. The result in females or prepubertal males is this, a condition of excessive body hair.

Androgens must be present for this, the most common form of baldness. In genetically predisposed adults, androgens inhibit hair growth.

Single or groups of epithelial cells that secrete a substance.

Glands associated with the skin

With few exceptions these glands are connected to hair follicles. Their secretion portions lie in the dermis and open into the hair follicles or directly onto skin surface. There are none in the palms and soles. Activity of this gland increases during adolescence.

Sebaceous glands secrete this oily substance.

1st role of sebum

When sebaceous glands of the face become enlarged because of accumulated sebum. The color is due to melanin and oxidized oil, not dirt.

Because sebum is nutritive to certain bacteria, blackheads can turn into these.

An inflammation of sebaceous glands that usually begins at puberty, when the sebaceous glands are stimulated by androgens.

There are 3 to 4 million of these glands. The cells realease sweat into hair follicles or onto the skin surface through pores.

Two main types of sweat glands based on their structure, location, and type of secretion.

Secrete outwardly. Much more common than apocrine sweat glands. Distributed through the skin of most regions of the body, especially in the skin of the forehead, palms, and soles.

Located mostly in the deep dermis [sometimes in the upper subcutaneous layer]. Excretory duct projects through the dermis and epidermis and ends as a pore at the surface of the epidermis.

About 600 mL per day. Consists of water, ions [mostly sodium and chlorine], urea, uric acid, ammonia, amino acids, glucose, and lactic acid.

Help regulate body temperature through evaporation. As sweat evaporates, large quantities of heat energy leave the body surface. Also release sweat in response to emotional stress such as fear or embarrassment.

Sweating in response to an emotional stress such as fear or embarrassment. First occurs on the palms, soles, and axillae and then spreads to other areas of the body.

Simple, coiled tubular glands. Found mainly the skin of the axilla, groin, areolae of the breasts, and bearded regions of the face in adult males.

Located mostly in the subcutaneous layer, and the excretory duct opens into hair follicles.

Slightly viscous, appears milky or yellowish in color. Contains the same components as eccrine sweat plus lipids and proteins. It is odourless, however when it interacts with bacteria on the surface of the skin it has a musky odor often referred to as body odor.

Start to function soon after birth.

Do not begin to function until puberty.

Apocrine sweat glands, along with eccrine sweat glands are active.

Secrete sweat during sexual activities.

Do not play a role in the regulation of body temperature.

Glands that are present in the external auditory canal.

Combine secretion of the ceruminous and sebaceous glands is a yellowish secretion known as this.

1st role of Cerumen

Plates of tightly packed, hard, dead, keratinized cells of the epidermis.

Components of a nail

Portion of the nail that is visible

The part of the body that extends past the end of the finger or toe

Part of the nail that is not visible

The thick, white part of the nail.

The stratum corneum of the epidermis in relation to the nail.

The proximal portion of the nail root. It contains dividing cells, which produce new nail cells.

Functions of the nails.

2nd role of sebum

3rd role of sebum

4th role of sebum

Are not present in the margins of the lips, nailbeds of the fingers and toes, glans penis, glans clitoris, labia minora, and eardrums.

2nd role of cerumen

3rd role of cerumen