What are the different types of specialized connective tissue?

Elastic

Recticular

Adipose

Cartilage

Bone

Blood

Loose

Dense regular

Dense irregular

Mesoderm, from mesenchymal cells.

Connective tissue of the face and head come from the neural crest (ectoderm)

Most abundant protein of the body

Produced by many cell types

At least 20 different types identified

Types distinguished by chemical composition, morphologic characteristics and function

One-third of amino acids are glycine

 Rich in proline and hydroxyproline

Hydroxyproline & Hydroxylysine are unique to collagen

composed of three polypeptide alpha chains; each chain is coded by a different gene; each chain coils into triple helix

procollagen peptidase

Newly formed molecule is called tropocollagen

Composed of microfibrils (which are made of fibrillin)

Elastin: contains desmosine and isodesmosine (each formed from 4 lysine residues & rich in proline and glysine)

Contains fibroblasts, smooth muscles cells, and chondrocytes

stretches easily and returns to shape

Resistant to boiling, acid, and protease digestion

Fibers branch (unlike collagen)

Forms cloth-like structures in walls of some blood vessels

Need Weigert's Stain to see fibers

Loose connective tissue

Elastic connective tissue

Elastic Cartilage

Elastic arteries

ligaments

dermis

Type III collagen that is heavily glycosylated

contains glycoproteins, other collagens, and proteoglycans

Cells: fibroblasts, recticular cells (hemopoietic), and Schwann Cells

Thin fibers

fibers branch

Form flexible network

Argyrophilic (silver loving)

PAS-positive - high content of glycoproteins

Spleen

lymph nodes

liver

endocrine glands

Fill spaces

Lubricant

very viscous barrier

bind cells to fibers

Characteristics: colorless, transparent (difficult to stain), hydrated, Gel-like consistency

Composition: glycoproteins, glycosaminoglycans, proteoglycans

protein component is dominant

more globular than proteoglycans

carbs are arranged in branched structure (but not repeating disaccharide fashion)

Play role in adhesion

Binds to integrins anchored in cell membranes

Fixed cells 

Most common cell type in connective tissue

Synthesizes fibers and ground substances

Least specialized CT cell type

Young fibroblasts: oval-nucleus, prominent nucleolus, many cell processes, well-developed Golgi, lots of RER

Mature fibroblasts: smaller, spindle-shaped, flattened, fewer processes, darker elongated nucleus, sometimes called fibrocyte

Wandering cell

Widely distributed

Ingest dead cells, cellular debris, and bacteria

Contain lysosomes

Immune response: present antigens to lymphocytes

Hard to identify at light microscope level unless ingesting something

Develop from B lymphcytes

Synthesize and release antibodies

Common in CT where bacteria enters (ie intestinal mucosa, mammary gland

Oval cells with eccentrically placed nucleus

Heterochromatin arranged in clockface pattern

Wandering cell

Widely distributed esp skin and mucous membranes of digestive and respiratory tracts

Contains granules

Central nucleus

Participates in inflammatory response: degranulation

Histamine - allergic response and inflammatory reactions

Heparin: anticoagulant

Most abundant

Fills spaces supports epithelial tissue

Cells: fibroblasts, macrophages

Few cells, much ground substances, some fibers (elastic and collagen)

Delicate and flexible but not resistant to stress

Locations: Dermis, hypodermis, lines cavities, glands, supports epithelial cells

Type of CT proper

Mostly fibers (collagen), few cells, some ground substance

Resistant to stress

Less flexible than Loose CT

Irregular: collagen bundles w/o orientation (found in dermis, submucosa of digestive tract, capsules around organs)

Regular: Collagen bundles arranged in patterns, resistant to traction forces, found in tendons

contains elastic fibers

appears yellow (fresh)

Rare

Locations: Yellow ligaments of vertebral column and suspensory ligaments of penis, external ear, walls of external auditory, eustatian tubes, epiglottis, laryngeal cartilage (corniculate and cuneiform)

Composition is same as hyaline cartilage, but has elastic fibers too

more flexible than hyaline cartilage

specialized loose CT

Provides architectural framework

Sponge-like structure

Recticular Cells (bone marrow)

Lots of fibers!

Cells: recticular cells, fibroblasts

Found in bone marrow, lymph node spleen

specialized CT

Abundant Ground substance - esp Hyaluronic acid

Jelly-like consistency

Few fibers

Mainly fibroblasts

Locations: Nucleus pulposus of intervertebral disks, prinicipal component of umbilical cord (Wharton's Jelly), Pulp of young teeth

Specialized CT

recticular fibers

Cells: adipocytes

Very little ground substances

CHaracteristics: highly vascularized, unilocular or multilocular

Functions: store energy (tricglycerides), shock absorber, thermal insulation, fills spaces

Brown fat

limited distribution - little in adults

Helps regulate temperature in newborns

No new cells formed after birth

Cells: smaller than unilocular, numerous mitochondria, highly vascularized, transfers stored energy into heat,numerous lipid droplets, central spherical nucleus

White fat

Distribution determined by age and sex

highly vascularized

Cells: lipid removed during processing, signet ring cell, eccentric flattened nuclei, most cytoplasm around nucleus, droplets not surrounded by membrane, basal lamina, incomplete lobules, number of cells increases only short time after birth, lipid droplet in cells increases in size

deficiency in iduronate sulfatase

GAGs affected = dermatan and heparan sulfate

Symptoms: mild & severe forms, only X-linked MPS, dystosis multiplex, organomegaly, facial & physical deformities, no corneal clouding, mental retardation, death before 15 except mild form (age 20-60)

deficiency in L-iduronase

GAGs affected= dermatan and heparan sulfate

Symptoms: dystosis multiplex, corneal clouding, organomegaly, heart disease, dwarfism, mental retardation, early mortality

deficiency in heparan sulfatase

GAG affected = heparan sulfate

Symptoms: profound mental deterioration, hyperactivity, skin, brain, lungs, heart and skeletal muscle are affected in all four types of MPS