II. Connective Tissue  Supports and

protects body parts

 Manufactures blood cells Composed of widely scattered cells. Lie within nonliving material

    2 types of cells1. Produces and

maintains intercellular material which are composed of 3 types of protein fibers

A. collagenous   B. elastic  C. reticular 2. protects tissue from

infection

3 Types of Protein Fibers

Collagenous fibers (collagen) Elastic fibers (elastin) Reticular fibers (reticulum)

1. Collagenous Fibers (Collagen)

 Most abundant (10% total body weight)

 Thick wave like strands Flexible but tensile (resists

stretching) Found in tendons (connect muscle to

bones) Also used by body for tissue repair *scar tissue, binds skin tightly together

2. Elastic Fibers (Elastin)

  Not as strong as collagen  Elasticity and extensibility * Pinch skin and it returns to its normal shape

3. Reticular Fibers (Reticulum)

 Resists physical stress Not abundant in connective tissue

4 Types of Connective Tissue

Based on density of proteins) 1. Connective tissue proper 2. Cartilage 3. Bone 4. Blood-forming tissue and blood

1. Connective Tissue Proper  Each type has a cell called

fibroblast which produces the intercellular

material  3 types based on the fibroblast a. Loose connective tissue b. Adipose tissue c. Dense connective tissue

a. Loose Connective Tissue  Most widespread Structural anchor

to body parts Between skin

and muscles Surfaces of

organsKnown as areolar tissue (referring to little area)

b. Adipose Tissue Fat cells

called adipocytes

 Fat stored as triglyceridesProvides insulation and padding between organs

c. Dense Connective Tissue  Tightly packed

protein fibers Regular or irregular Regular are fibers

parallel to each other like tendons and ligaments (connect bones to bones)irregular are fibers not parallel like deep layers of skin (dermis) and external wrap around bones and cartilage.

2. Cartilage Harder than connective tissue properProtein fibers in thickened gel-like ground

substance called matrixMatrix maintained by “gristle” cells called

chondrocytes that lie in small chambers called lacunae which get nourishment from the perichondrium (dense connective tissue)

types of cartilage a.Hyaline b.Elastic c.Fibrocartilage

a. Hyaline  Bluish white Respiratory

tract Ends of

bones at movable joints Ends of ribs

b. Elastic  Yellowish Framework

of ears End of nose

Epiglottis (small opening to larynx)

c. Fibrocartilage  Thick

collagenous fibers

 Joints like kneesBetween intervertebral discs (padded joints)

QUESTIONS

Packet pp.59-60

3. Bone  Intercellular material is mineral salts and

collagenous fibers Hardest and most durable of all tissue.

Dense matrix Composed of matrix of osteocytes embedded in lacunae (chambers). Nourished by periosteum which is a membrane surrounding the bone. Canaliculi are channels through which nutrients reach bone cells

2 Types of Bonea. Compact boneb. Spongy bone

b. Spongy Bone  Not dense,

have spaces called red marrow (blood forming tissue)

 Form thin plates called spicules Interior of bones Packet p.61

4. a.) Blood-Forming Tissue and b.) Blood

a. Blood-forming tissueanufactures cellular

components of bloodContains 3

components i. Stem cells (produce blood cells) ii. Young blood cells (newly formed) iii. Protein (lacks

collagen, so is softest connective tissue)

       2 types i. Red marrow Hematopoietic tissue

(initiates production of all cells)

ii. Lymphoid tissue In lymph nodes In tonsils Spleen, thymus Iit is maturation

site of 2 types of W.B.C. 1. Lymphocytes 2. Monocytes

b. Blood  The WBC, RBC and

platelets are called formed elements and are surrounded by a fluid matrix called plasma

 Formed elements means the fibers of the matrix are dissolved proteinsCarries respiratory gases, nutrients and wastes

Packet p. 62Packet pages 57-62 should now be doneQuiz on all notes through blood