Types of C.T.Fibers  There are three(3) types of C.T.  1-white collagennous fibers  2-yellow elastic fibers  3-reticular fibers

1-White Collagenous Fibers  Shape:  colourless wavy branching bundles,the fibers run paralled to each other  Charcter:  soft,strong&flexible but not elastic fibers

 Structures:  formed of protein known as (collagen) which can be digested by pepsin&trypsin enzymes  Staining:  collagenous fibers are acidophilic,  stain pink with eosin,red in  van-Gison&blue with Mallory stain

Types of collagen  There are five(5) types of collagen  1-Type I collagen:  Present:  losse C.T.,White fibro-cartilage,bone&teeth this type is formed by fibroblast,osteoblast,odontoblast  2-Type II collagen:  hyaline&elastic cartilage&formed by chondroblast

 3-Type III collagen:  skin,smooth muscle&reticular fibers formed by fibroblast&by smooth muscle cells  4-Type IV collagen: present in the basement  membrane of epithelial tissue&lenes of eye,It formed by fibroblast&by endothelial cells  5-Type V collagen:  in placenta,it is formed by fibroblast

2-Elastic fibers  Shape:  fine,straight branching fibers  Carachter:  the fibers branched&anastomose with each other  They run singly&not in bundles  Appear yellow in fresh state

 Structures:  formed of protein known as elastin which is resistant to chemical and to boiling  Can digested by the pancreatic elastase enzyme  Staining:  brown with orcein,black with verhoeff and yellow with van-Gison

Orecin Stain for Elastin – purple “ribbon candy”

3-Reticular Fibers  Shape:  they are thin,branched anastomose to form anetwork or reticulum  Strucures:  -formed of protein known as collagen type III  -Staining: Black with silver

Sliver Stain for Reticular Fibers

PAS stain of epithelial basement membranes (BM)

Masson’s Trichrome Stain – blue = collagen

Areolar Tissue Pink = collagen Purple = elastin

following 6 types of C.T. proper  1-Areolar C.T.  2-Adipose tissue  3-Yellow elastic C.T.  4-White Collagenous C.T.  5-Reticular C.T.  6-Micoid C.T.

1-Areolar C.T.  Commone type in the human body contain all types of C.T.fibers&C.T. cells  Function:  packaging material for other tissue

 Structures:  formed of aloose matrix formed of mucopolysacchids contain areolar(spaces)filled with air or fluid  C.T. cells&C.T. fibers are embedded in the loose matrix  C.T. cells are mainly fibroblasts,macrophages,fat &mast cells  C.T. fibers are mainly collagenous which are found in dermis of skin

 Sites:  1-submucosa of digestive tract  2-Present in all over the body except brain tissue&under dermis of skin  3-pleura,peritoneum&pericardium  4-under epithelial lining of organs  5-around the organs&blood vessels

2-Adipose C.T .  The fat cells develop from(UMC) transformed in lipoblast then into fat cells

There are 2 types of adipose C.T.  A.White Adipose Tissue  B.Brown Adipose tissue

A-White adipose tissue  Composed of large fat cells  These fat cells have eccentric flat nuclei  -the rim of cytoplasm around the nuclei contain few cell organelles  These fat cells can form fatty acids from glucprotien processes is regulate by hormones as insulin  This type affect by hormones&by the restriction of diet(regime)

Function of White Adipose C.T.  -Heat insulator&fat storge areas  Gives the body normal shape  Sites:  1-under the skin(in female)present in mammary glands&gluteal region  2-Around the kidney&blood vessels  3-in mesentry,omentum,abdominal wall

B-Brown adipose C.T .  Formed of small fat cells filled with many droplets of pigmented lipid  Develops mainly in the emrbyo from UMC.persist for few months after birth,supplies new born infant with heat to protect them from cold

 Function:  Heat generator,gives,heat to the different body organs  Site:  Interscapular region,axillary region,mediastinal around the thoracic aort  Present:  Eyelid,lung

3-Elastic C.T.  Appears yellow when present in afresh condition  -stained brown with orecin stain  -elastic fibers separated with areolar C.T.  -elastic tissue stretchable  -elastic tissue is present in the form of elastic membranes as in aorta

 Site:  -aorta&large arteries  -bronchi,bronchioles&around alveoli of lung  -ligment nuchae(in the back of the neck)to facilitate movments of trunk&neck

4-White Collagenous  Very dense type of C.T.form collagenous fibers  -seperated from each other by areolar C.T.  Arrangement of the collagenous bundles  White fibrous C.T.may be regular or irregular  Fibroblast===tendon cells  The fibroblast are triangular in shape with basophilic cytoplasm cell&their nuclei are oval in shape

Type of white collagenous C.T .  1-regular white collagenous C.T. regular collagenous bundles present cornea,eye,tendons of muscle  2-Irregular white collagenous:irregular collagenous bundles

Present:  1-sclera  2-capsule  3-dura mater  4-perichondrium,periosteum  5-Reticular C.T.  From the stroma or background of glands

5-Reticular C.T.is formed of  a-reticular fibers which are thin fibers  b-reticular cells which are stellate shape cells  c-mononuclear phagocitic cells  the reticular cells&fibers form anetwork  Staining:  Brown with silver stain

 Site:  1-present in the stroma of bone marrow  2-stroma or framework of the spleen,lymph nodese,liver,testis,ovary&endocrine glands  3-kidney,lung&gastro-intestinal tract

6-Mucoid C.T.  Fromed of  1-mucoid cells which are young fibroblast  2-matrix formed of hyaloronic acid&collagenous fibers

Site of mucoid C.T .  1-umbilical cord(between the blood vessels of umbilical cord where it is calles wartons jelly)  2-in adult it is present in vitreous of the eye ball&pulp of growing teeth

The pigmented type of C.T.  Is an adult type of C.T. proper similar to areolar C.T.  It is very rich in pigment cells  Present in the iris,ciliary body&choroids of the eye

Function of C.T. proper  Support&connects organs&tissue together  C.T.plasma cells secret antbodies,mast cells secrete histamine&heprine  C.T.is important in regeneration&healing of wounds  Defency&immune response

Cartilage  Definition:  it is firm rigid flexible dense C.T poor in blood supply  Structures:  1-cartilage cell:young&mature chondrocytes  2-C.T. Fibers:collagenous&elastic C.T.Fibers  3-Matrix:formed of collagen glycoproteins

Cartilage Cells  1-Young Chondrocytes== Condroblast==Chondrogenic cells  -flat cells with flat nuclei they can divide  -cytoplasm is basophilic contains all organoid&inclusions  -present mainly under the perichondrium

2-Mature Chondrocytes  Rounded cells with round nuclei  -cytoplasm is basophilic contain all organoids&inclusion,rich in glucogen fat&phosphatase enzymes  Condrocytes can divid present in group called cell nests  -the groups of cartilage cells are surrounded with aspaces called lacuna

Function of mature chondrocytes:  synthesis type II collagen proteoglycans,hyaluronic acid&chondroprotein of the matrix

Matrix of cartilage  -rubbery in consistency  -formed of proteins called proteoglcans,hyaluronic acid  -glycoprotein&type II collagen  Basophilic in staining,blue with hematoxline

Type of Cartilage  Carilage cells&the C.T. fibers are embeded in rubbery matrix in order,following 3 types of cartilage  1-Hyaline cartilage(appears glassy)  2-Elastic fibro-cartilage(contain elastic fibers)  3-white fibro-cartilage(white collagenous bundles)

Hyaline Cartilage  Commonest type of cartilage,translucent&pale blue in color  The matrix is poor in blood supply  -covered by avascular membrane or perichondrium  -perichondrium is formed of  a-outer fibrous layer of collagenous bundles:rich in B.V.&fibroblast  b-Inner chondrogenic layer formed of chondroblast which can be change into chondrocytes can divid&can secrete new matrix

Function of perichondrium  1-supplies cartilage with blood  2-chondroblast form matrix of cartilage  3-provides an attachment for muscles

 Embeded in matrix are 2 types of cartilage cells  1-Young chondrocytes: flat cells surround by lacunne they have flat nuclei&basophilic cytoplasm present single cells under the perichondrium

2-Mature Chondrocytes  Spherical cells with round nuclei&basophilic cytoplasm rich in phosphatase enzymes  Each cells is present in aspace called Lacune

Site of hyline cartilage  1-costal cartilages present in thoraciccage  2-cartilage of respiratory passages,nose,trachea,bronchi,larnx  3-articular surface of joints(cartlage is not carred with perichondrium)

2-Yellow elastc fibro-cartilage  This type of carilage is similar structures to hyaline cartilage but  a-the matrix is rich in elastic fibers surround by cartilage cell surround by perichondrium  b-this cartilage is flexible&yellow in color due to presence of elastic fibers

site of elastic-fibro cartilage  1-Epiglotitis,artetenoid,corniculate  2-External ear&Eustachian tube

3-White fibro-cartilage  Characteristic of fibro-cartlage  1-simillar to hyaline cartilage very rich in type I collagen fibers  2-matrix is acidophilic due to presence of type I collagen  3-formed of chondrocytes  4-cartilage cells arranged in rows or in columns  5-the white F-C. is not covered by chondrium  6-cartlage cells are separated by acidophilic collagenous bundles

Site of W.F.C. in the body  1-presence in the intervertebral disc  2-semilunar cartilage of knee joints  3-symphysis pubis,acetabulum  4-discs between sterno- clavicular&mandibular joint  5-terminal parts of the muscle tendon

Function  1-maintaining the patency of respiratory passages  2-cartilage&bone form the skeleton of body  3-cartilage forms asmooth firm surface for the articular joints  3-cartilage is essential for growth of bone before birth  4-cartilage&bone protect essential organs as lung,brain&bone marrow

Young cartilage can grow out by the following 2 different methods  1-Interstitial growth:  from groups of young chondrocytes secret the matrix resulting in growth of cartilage  2-Appositional growth:  chondroblast of the perichondrium become transformed into chondrocytes which secret the matrix

(resorcin-fuchsin stain) Elastic Fibers Elastic Fibers- silver stain Elastic Cartilage- pinnae of ear Elastic Cartilage Matrix hyaluronic acid chondroitin sulfate kertatin sulfate Fibers elastic (elastin) Typical Locations external ear walls of external auditory canal and eustachian tubes epiglottis & larynx bridge of nose Properties resiliency and pliability

Fibroblasts Collagen Perichondrium Blood vessels Chondroblasts Hyaline matrix Isogenous groups (nests of chondrocytes)

Hyaline cartilage Chondrocytes nucleus Matrix Lacuna EM : hyaline cartilage