Module 4 Tissues Flashcards
Define the term tissue.
A tissue is a group of similar cells that usually have a similar embryological origin and are specialized for a particular function.
Name the 4 primary adult tissue types.
Epithelial tissue, connective tissue, muscle tissue, and nervous tissue.
Describe epithelial tissue.
Covers the body surfaces; lines hollow organs, body cavities, and ducts; and forms glands. Epithelial tissue provides external protection for underlying tissue.
Describe connective tissue.
Protects and supports the body and it’s organs, binds organs together, stored energy reserves as fat, and provides immunity.
Describe muscle tissue.
Is responsible for most movement and generation of force.
Describe nervous tissue.
Initiates and transmits action potentials (nerve impulses) that help coordinate body activities, monitors the external environment, and contributes to homeostasis.
Describe the cell shapes and arrangement of layers for surface epithelium.
Shape: squamous, cuboidal, columnar.
Arrangement of layers: simple, pseudostratified, stratified.
Describe the general features of epithelial tissues.
Arranged in sheets (single or multiple), packed cells with many cell junctions, apical surface and basal surface attached to a base membrane, has nerve supply and high capacity for renewal, avascular.
Describe the basement membrane.
Made of a cellular layer of collagen and glycoproteins called the basal lamina; often underlain w/a layer of reticular fibers and glycoproteins called the reticular lamina.
What functions do the epithelia include?
Protection, filtration, lubrication, secretion, digestion, absorption, transportation, excretion, sensory reception, and reproduction.
Describe the cell shapes.
Squamous (flat), cuboidal (cube-like), columnar (tall rectangular), and transitional (variable).
Describe the cell layers and their arrangements.
Simple (1 layer), stratified (several layers), pseudostratified (1 layer that appears as several).
Describe the simple squamous epithelium.
Consists of a single layer of flat, scale-like cells. It is adapted for diffusion and filtration and is found in the lungs and kidneys.
It is found in parts of the body that are subject to little wear and tear. The _____ lines the heart and blood vessels.
Endothelium
The ___ lines the thoracic and abdominopelvic cavities and covers the organs with them.
Mesothelium
Describe the simple cuboidal epithelium.
Consists of a simple layer of cube-shaped cells, and performs the functions of secretion and absorption. Found in the kidneys.
The simple columnar epithelium consists of a single layer of rectangular cells, which can have 2 forms: _____ and _____.
Nonciliated simple columnar epithelium and ciliated simple columnar epithelium
Describe nonciliated simple columnar epithelium.
Contains microvilli to increase surface area. Lines most of the gastrointestinal tract.
What do goblet cells do?
Secrete mucous
Describe ciliated simple columnar epithelium.
Contains cells with cilia-motile, hair like processes that help to move fluids or particles along a surface. Lines the uterine tubes.
Describe stratified epithelium.
Has at least 2 layers of cells, more durable and protective.
Describe pseudostratified epithelium.
Has only 1 layer but gives the appearance of many. All cells are attached to the basement membrane, but some do not reach the apical surface
Describe pseudostratified ciliated columnar epithelium.
The cells that reach the surface either secrete mucus (goblet cells) or bear cilia that sweep away mucus and trapped foreign particles. Lines the airways of most upper respiratory tract.
Describe pseudostratified nonciliated columnar epithelium.
Contains no cilia or goblet cells. lines ducts if many glands; parotid glands.
Describe stratified squamous epithelium.
Consists of several layers of cells in which the top layer of cells is flat and the deeper layers vary in shape from cuboidal to columnar. Located in the skin and vagina.
The ___ ___ replicate by mitosis and ultimately work their way to the surface.
Basal cells
Describe keratinized stratified squamous epithelium.
A tough layer of keratin (a protein resistant to friction w/a capacity to repel bacteria) is deposited in the surface cells.
Describe non keratinized stratified squamous epithelium.
Does not contain keratin and remains moist.
Describe stratified cuboidal epithelium.
A rare tissue that consists of 2 or more layers of cube-shaped cells w/mainly a protective function. Found in the esophagus.
Describe stratified columnar epithelium.
Consists of several layers of cells of which only the top layer is columnar. It is somewhat rare and functions in protection and secretion.found in the pharynx, excretory ducts of some glands such as esophageal glands.
Describe transitional epithelium.
Consists of several layers of cells; their appearance is variable. Capable of stretching and thus permits the distention of an organ. It lines the urinary bladder and portions of the ureters and urethra.
What is a gland and name the 2 types.
A single cell or mass of epithelial cells adapted for secretion. Endocrine and exocrine.
____ glands are ductless; their secretory products (hormones) enter the extracellular fluid and diffuse into the blood.
Endocrine
____ glands (sweat, oil, digestive glands) secrete their products into ducts that empty at the surface of the covering and lining of the epithelium or directly onto a free surface.
Exocrine
What is the function of the endocrine glands?
Produce hormones that regulate various body activities.
What is the function of the exocrine glands?
Produce substances such as sweat, oil, earwax, saliva, or digestive enzymes.
Describe the general characteristics of connective tissues and discuss their differences from epithelial tissue.
CT is the most abundant and widely distributed tissue in the body. Unlike epithelial tissue, CT do not occur on free substances and is highly vascular (except for cartilage and tendons). CT like epithelium had a nerve supply.
What are the 3 basic elements of connective tissues?
Cells, ground substance and protein fibres (the latter 2 combine to form the matrix).
What are the representative cells and fibres present in the connective tissues?
Fibroblasts (most numerous in CTs), collagen fibres, mast cells, plasma cells, ground substance, neutrophils, eosinophils, adipocytes, elastic fibres, macrophages, and reticular fibres.