Epithelium Flashcards
Arrangement of epithelium wherein cells are found in a single layer attached to the basement membrane
Simple
Arrangement of epithelium wherein cells are found in 2 or more layers stacked atop each other.
Stratified
Arrangement of epithelium wherein a single layer of cells that appears to be multiple layers due to variance in height and location of the nuclei in the cells.
Pseudostratified
Arrangement of epithelium wherein cells are rounded and can slide across one another to allow stretching.
Transitional
Shape of epithelium in which they are flat, thin, scale-like cells
Squamous
Shape of epithelium in which the cells have a basic cube shape. Typically, the cell’s height and width are about equal.
Cuboidal
Shape of epithelium in which there are tall, rectangular or column shaped cells. Typically taller than they are wide.
Columnar
These are hair-like appendages attached to the apical surface of cells that act as sensory structures or to produce movement.
Cilia
These are specialized cells that produce mucus to lubricate and protect the surface of an organ
Goblet cells
These are finger-like projections that arise from the epithelial layer in some organs. They help to increase surface area allowing for faster and more efficient adsorption.
Villi
These smaller projections that arise from the cell’s surface that also increase surface area. Due to the bushy appearance that they sometimes produce, they are sometimes referred to as the ___________ of an organ.
Microvilli, brush border
It is used to refer to any space or opening inside an organ or structure
Lumen
Description: Single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm; the simplest of the epithelia
Function: Allows passage of materials by diffusion and filtration in sites where protection is not important; secretes lubricating substances in serosae
Location: Kidney glomeruli; air sacs of lungs; lining of heart, blood vessels, and lymphatic vessels; lining of ventral body cavity (serosae).
Simple squamous epithelium
The lungs contain small air sacs called _________ and these structures are composed of a single layer of flattened cells called simple squamous epithelium.
alveoli
Description: Single layer of cubelike cells with large, spherical central nuclei.
Function: Secretion and absorption
Location: Kidney tubules; ducts and secretory portions of small glands; ovary surface
Simple cuboidal epithelium
Description: Single layer of tall cells with round to oval nuclei; some cells bear cilia; layer may contain mucus-secreting unicellular glands (goblet cells).
Function: Absorption; secretion of mucus, enzymes, and other substances; ciliated type propels mucus (or reproductive cells) by ciliary action.
Location: Nonciliated type lines most of the digestive tract (stomach to anal canal), gallbladder, and excretory ducts of some glands; ciliated variety lines small bronchi, uterine tubes, and some regions of the uterus.
Simple columnar epithelium
Description: Single layer of cells of differing heights, some not reaching the free surface; nuclei seen at different levels; may contain goblet cells and bear cilia.
Function: Secretion, particularly of mucus; propulsion of mucus by ciliary action.
Location: Nonciliated type in male’s sperm-carrying ducts and ducts of large glands; ciliated variety lines the trachea, most of the upper respiratory tract.
Pseudostratified columnar epithelium
Description: Thick membrane composed of several cell layers; basal cells are cuboidal or columnar and metabolically active; surface cells are flattened; in the keratinized type, the surface cells are full of keratin and dead; basal cells are active in mitosis and produce the cells of the more superficial layers.
Function: protects underlying tissues in areas subjected to abrasion.
Location: Nonkeratinized type forms the moist linings of the esophagus, mouth, and vagina; keratenized variety forms the epidermis of the skin, a dry membrane.
Stratified squamous epithelium
Description Resembles both stratified squamous and stratified cuboidal or columnar; surface cells dome shaped or squamouslike, depending on the degree of organ stretch.
Function: Stretches readily and permits distension of urinary organ by contained urine.
Location: Lines the ureters, bladder, and part of the urethra
Transitional epithelium
___________ and __________ are rare occurrences in epithelial tissue.
Stratified cuboidal and stratified columnar
It occurs in the excretory ducts of sweat glands and salivary glands. They are also found in mammary glands and in the developing ovarian follicles.
Stratified cuboidal epithelium
