Tissue Organization

simple squamous epithelium

• single layer of flat cells, very thin

• rapid diffusion of gases and molecules

• lining of air sacs of lungs, endothelium (lining blood vessels), kidney glomerulus

simple cuboidal epithelium

• single layer cube-shaped cells, round nucleus

• secretion and absorption; form small ducts and tubules

• kidney tubukes, small duct of glands, ovary surface

simple columnar epithelium (non-ciliated)

• tall columns like cells; oval nuclei near basal surface

• absorption, secretion of mucus and enzymes, protection

• lining of stomach, intestines, and gallbladder (digestive system)

simple columnar epithelium (ciliated)

• column-like cells with cilia on apical surface; nuclei basal

• movement of mucus or ocyte

• lining of uterine tubes, parts of uterus, small bronchi

pseudostratified ciliated columnar epithelium

• single layer but appears stratified; almost all cells contact basement membrane; cilia & goblet cells present

• secretion of movement of mucus protection of airways

• lining of trachea & upper respiratory tract

pseudostratified non-ciliated epithelium

• pseudostratified columnar epithelium without cilia

• absorption and protection

• male reproductive tract & large ducts of some glands

stratified squamous non-keratinized epithelium

• multiple cell layers; basal cells cuboidal/columnar; surface cells flat, moist; no surface keratin

• protection from abrasion in moist areas

• lining of mouth, esophagus, vagina, anal canal

stratified keratinized squamous epithelium

• multiple cell layers; surface cells flat and dry filled with keratin

• protection from abrasion, water loss, and microbial invasion

• epidermis of skin

transitional epithelium

• multiple layers; surface cells are dome-shaped when relaxed; flatter when stretched

• stretch and recoil; protection from urine

• lining of urinary bladder, ureters, proximal urethra

loose areolar connective tissue

• loose arrangement of collagen and elastic fibers; abundant ground substance; many cell types

• protection; strengthens walls of ducts; limited secretion & absorption

• large duct of sweat glands, mammary glands, salivary glands

adipose tissue

• large adipocytes with peripheral nucleus; very little matrix; cells closely packed (fat tissue)

• energy storage, insulation, cushioning, hormone production

• subcutaneous layer, aliens kidneys and eyeballs, within abdomen, breast

reticular connective tissue

• network of fine reticular fibers with numerous reticular cells

• some internal skeleton supporting other cell types

• lymph nodes, spleen, bone marrow

dense regular connective tissue

x parallel, densely packed collagen fibers; little ground substance

strong attachment in one direction; resist tension along fiber orientation

tendons, most ligaments, aponeuroses

dense irregular connective tissue

• irregularly arranged collagen fibers; fibroblasts

• strength and resistance to tension in many directions

• dermis of skin, fibrous capsules of organs

elastic connective tissue

• densely packed elastic fibers, some collagen; fibroblasts in between

• allows stretch and recoil

• walls of large arteries, certain ligaments

hyaline cartilage

• glassy, smooth matrix with fine collagen fibers not easily seen

• support, cushioning, smooth surfaces for joint movement

• articulate cartilages of joints, nose, trachea

elastic cartilage

• like hyaline but with visible elastic fibers

• flexible support, maintain shape

• external ears, epiglottis

fibrocartilage

• rows of chondrocytes between thick bundles of collagen fibers; least flexible

• strong shock absorption, resist compression

• intervertebral discs, pubic symphysis, menisci

skeletal muscle tissue

• long, cylindrical fibers; multinucleated; obvious striations voluntary control

• voluntary movement, posture, heat production

• attached to bones, facial muscles

smooth muscle tissue

• spindle-shaped cells single central nucleus- no visible striations; involuntary

• propel substances, regulated diameter of tubes, adjust pupil size

• wall of hollow organs, blood vessels, respiratory tract, arrector pill muscles