Chapter 6 - Skin and membranes Flashcards
epithelial membrane
membranes composed of epithelial tissue and an underlying layer of fibrous connective tissue
connective tissue membrane
membranes composed exclusively of various types of connective tissue. No epithelial cells are present in this type of membrane
cutaneous membrane
another name for the body’s skin, made up of the dermis and epidermis
serous membrane
membranes lining closed internal body cavities, made up of two layers called the parietal and visceral layers
parietal layer
the serous membrane that lines the walls of a body cavity much like wallpaper covers the walls of a room
visceral layer
the portion of the serous membrane that folds inward to cover the surface of organs within a body cavity
pleura
the serous membrane around each lung
peritoneum
in the abdominal cavity, the serous membrane covering most of theorgans
pericardium
the serous membrane around the heart
pericardial fluid
a lubricating fluid between the parietal and visceral layers of the pericardium
pleurisy
a very painful pathological condition characterized by inflammation of the serous membranes (pleura) that line the chest cavity and cover the lungs. Pain is caused by irritation and friction in the inflamed pleura as the lung rubs against the wall of the chest cavity. In severe cases, the inflamed surfaces of the pleura fuse together and permanent damage may develop.
peritonitis
inflammation of the serous membranes in the abdominal cavity. Peritonitis can be a serious complication of an infected appendix.
mucous membranes
epithelial membranes that contain both an epithelial layer and a fibrous connective tissue layer. These membranes line body surfaces opening directly to the exterior of the body. Examples of mucous membranes include those lining the respiratory, digestive, urinary, and reproductive tracts. The epithelial component of a mucous membrane varies, depending on its location and function. In most cases, the cell composition is either stratified squamous or simple columnar epithelia
mucus
a thick, slimy material produced by the epithelial cells of most mucous membranes; it keeps the mucous membranes moist and soft
lamina propria
the fibrous connective tissue underlying the epithelium in mucous membranes
mucocutaneous junction
the transitional area that serves as a point of “fusion” where skin and mucous membranes meet. Such junctions lack accessory organs such as hair or sweat glands that characterize skin. These transitional areas are generally moistened by mucous glands within the body orifices or openings where these junctions are located. The eyelids, lips, nasal openings, vulva, and anus have mucocutaneous junctions that may become sites of infection or irritation.
bursae
fluid-filled sacs between tendons and bones that function as cushions
synovial membrane
a connective tissue membrane lining the spaces between bones and joints that secretes synovial fluid
epidermis
the outermost layer of the skin. It is a relatively thin sheet of stratified squamous epithelium.
dermis
the deeper of the two layers. It is thicker than the epidermis and is made up largely of connective tissue.
hypodermis
also called subcutaneous tissue or superficial fascia; it is a thick layer of loose connective tissue and fat that lies below the dermis and connects it to the muscles and bones. Fat in the subcutaneous layer insulates the body from extremes of heat and cold. It also serves as a stored source of energy for the body and can be used as a food source if required. In addition, the subcutaneous tissue acts as a shock-absorbing pad and helps protect underlying tissues from injury caused by bumps and blows to the body surface.
stratum germinativum
the basal layer of the epidermis consisting of a single row of columnar or cuboidal epithelial cells that continually divide and replace the rest of the epidermis as it wears away
basal layer (epidermis)
the innermost layer of the epidermis; it contains small round cells called basal cells
keratin
a tough, waterproof material that provides cells in the outer layer of the skin with a horny, abrasion-resistant, and protective quality; it is a fibrous protein forming the main structural constituent of hair, feathers, hoofs, claws, horns, etc.
basal cell
a type of cell in the innermost layer of the epidermis or other epithelial tissue
stratum corneum
the outermost layer of the epidermis
melanin
a brown pigment produced by cells in the basal layer called melanocytes; the more melanin in the skin, the darker the skin color; melanin protects against UV radiation
melanocytes
a mature melanin-forming cell, especially in the skin
cyanosis
a bluish discoloration of the skin resulting from poor circulation or inadequate oxygenation of the blood
basement membrane
also called a basal lamina; a sheet of proteins and other substances to which epithelial cells adhere and that forms a barrier between tissues
dermal-epidermal junction (DEJ)
the area of tissue that joins the epidermal and the dermal layers of the skin
dermal papillae
small, nipple-like extensions of the dermis into the epidermis; they play an important role in stabilizing the dermal-epidermal junction
blister
a baglike fluid-filled elevation of the skin caused by an irritant such as heat, friction, or a chemical
papillary layer
the upper region of the dermis where the dermal papillae reside