Simple squamous epithelium

Desciption: Single layer of flattened cells

 disc-shaped nuclei

 sparse cytoplasm

Function: Diffusion and filtration (in sites where protection is not important)

Location: Kidney glomeruli, air sacs of lungs

Simple cuboidal epithelium

Definition: single layer of cubelike cells with large, spherical nuclei

Function: Secretion and absorption

Location: kidney tubules, ducts and secretory portions of small glands, ovary surface

Simple columnar epithelium

Description: single layer of tall cells with round to oval nuclei

Function: absorption, secretion of mucus and other enzymes (ciliated type propel mucus0

Location: non-ciliated line digestive tract, ciliated line small bronchi

Pseudostratified columnar epithelium

Description: single layer of cells of differing heights, nuclei seen at different levels

Function: secretion, particilularly mucus, ciliated versions propel mucus

Location: ciliated variety line trachea, non-ciliated type in male sperm-caryying ducts

Stratified squamous epithelium

Description: thick membrane composed of several cell layers.  Basal cells are cuboidal or columnar.  Surface cells a flattened (squamous).

Function: protects underlying tissue in areas subject to abrasion.

Location: keratinized type form epidermis. non-keratinized form moist linings of esophagus, mouth, and vagina.

Stratified cuboidal epithelium

Description: generally two layers of cubelike cells.

Function: Protection

Location:  largest ducts of sweat glands, mammary glands, and salivary glands

Stratified columnar epithelium 

Description: several cell layers.  basal cells are cuboidal, superficial cells are elongated and columnar.

Function: Protection and secretion

Location: Rare in the body, small amounts in male urethre and in large ducts of some glands

Transitional epithelium

Description:  resembles stratified squamous and stratified cuboidal.  Basal cells are cuboidal or columnar, surface cell are dome or squamous shaped, depending on stretch.

Function: stretches readily and permits distension of urinary organ by contained urine.

Location: lines ureters, urinary bladder, and part of the urethra. 

Areolar (Connective tissue proper, loose)

Description: gel-like matrix with all three fiber types; cells: fibroblasts, macrophages, mast cells, and some white blood cells. 

Function: wraps and cushions organs

Location: widely distributed under epithelia of body, packages organs, surrounds capillaries

Adipose (Connective tissue proper, loose)

Description: Matrix as in areolar, but very sparse.  closely packed adipocytes.  Nucleus is pushed aside by large fat droplets. 

Function: provides reserved fuel, insulates against heat loss, supports and protects organs. 

Location: under skin, around kidneys and eye-balls, within abdomen and breasts. 

Reticular (Connective tissue proper, loose)

Description: network of reticular fibers in a typical loose ground network

Function: fibers form a soft internal skeleton that supports other cell types, including white blood cells

Location: lymphoid organs

Dense regular (Connective tissue proper, dense)

Description: primarily parallel collagen fibers, a few elastic fibers, major cell type is fibroblast

Function: attaches muscles to bones or to muscles, attaches bones to bones

Location: tendons, most ligaments

Elastic (Connective tissue proper, dense)

Description: dense regular connective tissue containing a high proportion of elastic fibers

Function: allows recoil of tissue following stretching

Location: walls of large arteries

Dense irregular (Connective tissue proper, dense)

Description: primarily irregularly arranged collagen fibers, some elastic fibers, major cell is fibroblast

Function: able to withstand tension exerted in many directions

Location: fibrous capsules of organs and of joints; dermis of skin, submuscosa of digestive tract

Hyaline cartilage

Description: amorphous but firm matrix, collagen fibers form an imperceptilbe network; chondoblasts produce the matrix and when mature lie in lacunae

Function: supports and reinforces, resilient cushioning properties

Location: cartilages of the nose, trachea, and larynx

Elastic cartilage

Description: similar to hyaline cartilage, but more elastic fibers in matrix

Function: maintains shape of structure while allowing great flexibility

Location: supports the external ear; epiglotis

Fibrocartilage cartilage

Description: matrix similar to but less firm than that in hyaline cartilage; thick colllagen fibers predominate

Function: tensile strength with the ability to absorb compressive shock

Location: intevertebral discs

Bone (Osseous tissue)

Description: hard, calcified matrix containing many collagen fibers

Function: bone supports and protects, provides levers for muscles to act on

Location: bones

Blood

Description: red and white blood cells in fluid matrix

Function: transport of respiratory gases, nutrients, waste, and other substances

Location: contained within blood vessels

Nervous 

Description: neurons are branching cells; cell processes may be long and extended from nucleus containing cell body, also contains non-irritable supporting cells

Function: transmit electrical signals from sensory receptors and to effectors which control their activity

Location: brain, spinal cord, and nerves

Skeletal muscle

Description: long, cylindrical, multinucleate cells, obvious striations

Function: voluntary movement, locomotion manipulation, facial expression

Location: in skeletal muscles attached to bones or occasionally to skin

Cardiac muscle

Description: branching, striated, generally uninucleate cells that interdigitate at specialized junctions

Functions: as it contracts it propels blood into the circulation, involuntary

Location: walls of the heart

Smooth muscle

Description: spindle-shaped cells with central nuclei, no striations, cells arranged closely to form sheets

Function: propels substances or objects along internal passageways, involuntary control

Location: mostly in the walls of hollow organs