Epithelial Tissue
forms boundaries between different environments, protects, secretes, absorbs, filters
Location: lining of digestive tract organs and other hollow organs, skin surface (epidermis)
Connective Tissue
supports, protects, binds other tissues together
Location: bones, tendons, fat and other soft padding tissue
Nervous Tissue
internal communication
Location: brains, spinal cord, nerves
Muscular Tissue
contracts to cause movement
Location: muscles attached to bones (skeletal), muscles of heart (cardiac), muscles of walls of hollow organs (smooth)
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Characteristics of Epithelial Tissue
connective tissue support and specialized contacts
Specialized Contacts
binds adjacent cells, Tight Junctions, Desmosomes, Gap Junctions, Hemidesomosomes
Connective tissue support
basement membrane, noncellular basal lamina, and
adhesive sheet
Reticular lamina
network of collagen fibers, deep to basal lamina
Six functions of Epithelial tissue
Protection, Absorption, Filtration, Excretion, Secretion, Sensory reception
Stratified epithelia
two or more layers of cells
Simple epithelia
single layer of cells
Squamous
Flattened and scalelike
Cuboidal
Boxlike
Columnar
Tall; column shaped
Simple Squamous Epithelium
Allows materials to pass by diffusion and filtration in sites Location: Lining of ventral body cavity (serosae).
Simple Cuboidal Epithelium
Secretion and absorption
Location: Ovary surface.
Simple Columnar Epithelium
Absorption; secretion of mucus, enzymes, and other substances; Ciliated type propels mucus
Location: gallbladder, and excretory ducts of some glands
Pseudostratified Epithelium
Secrete substances, particularly mucus; Propulsion of mucus by ciliary action
Location: lines the trachea, most of the upper respiratory tract
Stratified Squamous Epithelium
Protects underlying tissues in areas subjected to abrasion
Location: linings of the esophagus, mouth, and vagina
Transitional Epithelium
Stretches readily, permits stored urine to distend urinary organs
Location: Lines the ureters, bladder, and part of the urethra
Gland
One or more cells that makes and secretes an aqueous fluid called a secretion
Exocrine Gland
secrete through ducts onto the surface of the gland
Endocrine Gland
release hormones into the surrounding fluid
Unicellular
The only important glands are mucous cells and goblet cells. Found in epithelial linings of intestinal and respiratory tracts. All produce mucin
Multicellular
Are composed of a duct and a secretory unit. Unbranched or Branched
Three types of secretion of multicellular glands
Merocrine, Apocrine, Holocrine
Merocrine
most common secretes products by exocytosis
Apocrine
accumulates products within but only apex ruptures
Holocrine
accumulates products within, then ruptures, killing the cell
Structural Elements of Connective Tissue
Ground substance, Fibers, Cells
Ground substance
Unstructured material that fills space between cells
Fibers
collagen, elastic, reticular
Collagen fibers
Strongest and most abundant type
Elastic fibers
Networks of long, thin, elastin fibers that allow for stretch and recoil
Reticular fibers
Short, fine, highly branched collagenous fibers. Branch, forming networks that offer more "give"
Cells of Connective tissue
"Blasts" cells, Fat cells, White blood cells, Mast cells, Macrophages
Areolar Loose Connective Tissue
Wraps and cushions organs, Plays important role in inflammation, Holds and conveys tissue fluid
Location: Surrounds capillaries.
Adipose Loose Connective Tissue
Provides reserve food fuel, Insulates against heat loss, Supports and protects organs
Location: Under skin in subcutaneous tissue
Reticular Loose Connective Tissue
supports free blood cells in lymph nodes, the spleen and bone marrow
Location: Lymphoid organs (lymph nodes, bone marrow, and spleen)
Dense Regular Connective Tissue
Attaches muscles to bones or to muscles, Attaches bones to bones
Location: Tendons, most ligaments, aponeuroses.
Dense Irregular Connective Tissue
Withstands tension, Provides structural strength
Location: Dermis of the skin
Elastic Dense Connective Tissue
Allows tissue to recoil after stretching
Location: Walls of large arteries
Blood (Fluid Connective Tissue)
Transport respiratory gasses, nutrients, wastes, and other substances
Location: Contained within blood vessels.
Skeletal muscle tissue
Found in skeletal muscle, Voluntary
Cardiac muscle tissue
Found in walls of heart, Involuntary
Smooth muscle tissue
Mainly in walls of hollow organs other than heart, Involuntary
Main component of the nervous system
Brain, spinal cord, nerves. Regulates and controls body functions
Cutaneous membranes
(the skin) covers the body surface
Mucous membranes
lines body cavities that are open to the exterior
Serous membranes
lines body cavities that are closed to the exterior
Tissue repair involves
regeneration, fibrosis
Regeneration
Same kind of tissue replaces destroyed tissue. Original function restored
Fibrosis
Connective tissue replaces destroyed tissue. Original function lost