Connective Tissue (CT)

Characteristics

1. CT is most varied tissue in make-up, location, and function

2. Lots of intracellular space= (matrix)

3. Matrix contains fibers and ground substance

4. Usually vascular

5. Made from mesenchyme- embryonic CT

CT Classification

CT

proper fluid supporting

dense loose

Areolar

adipose

reticular

I

rregular

regular

blood

lymph

cartilage bone

fiborous

elastic

hylaine

spongy

compact

elastic

Functions of CT

1. Establishes structural framework

2. Transport substances

3. Protection of organs

4. Supporting, surrounding, and interconnecting other tissue types

5. Storing energy reserves

6. Defending body from invading microbes

Types of CT

1. CT proper- ex. fat, tendons - divided into 2 types based on proportions of cells, fibers, ground substance

a. Loose

b. Dense

2. Fluid CT- ex. blood, lymph

3. Supporting CT- ex. Cartilage, osseous

Cells of CT

ALWAYS ( in CT proper)1. Fibroblasts- make ground substanceMAYBE• Macrophages- large amoeboid, engulf pathogens• Chondrocytes- cartilage cells• Adipocytes- fat cells• Erythrocytes- RBC• Mesenchymal- stem cells, respond to local injury by

making more cells• Mast cells-stimulate local inflammation after injuryMany others

Fibers of CT

1. Collagen- strongest, long, straight, unbranched, like rope, make up ligaments and tendons

2. Reticular- same fibers as collagen, web-like, support

3. 3. Elastic- branched, wavy, stretch and return to original length, connect vertebrae

CT proper1. Loose CT- “packing material”,

a. Areolar –separates skin from deeper tissues

CT proper1. Loose CT- “packing material”,

b. Adipose – store energy, insulate, protect (padding)

CT proper1. Loose CT- “packing material”,

c. Reticular- interlacing fibers create stroma(3-D network), inside organs of liver and spleen

CT proper2. Dense CT-”fibrous tissue”

a. Regular- collagen fibers run parallel

ex. Tendons

CT proper2. Dense CT-”fibrous tissue”

b. Irregular- collagen fibers interwoven in no pattern

ex. Nerve and muscle sheaths

CT proper

2. Dense CT-”fibrous tissue”

c. Elastic- a type of dense, regular, w/ more elastic fibers

ex- walls of bl.v

Fluid CT

1. Blooda. Formed elements- RBC, WBC, plateletsb. Plasma- watery matrix

2. Lymph

Supporting CT

1. Cartilage

a. avascular

b. Surrounded by perochondrium (for attachment)

c. Cells called chondrocytes, located in lacunae or nests

d. Matrix is gel-like

2. Types of Cartilage

A. Hyaline

-most common in body

-few, closely packed collagen fibers

-tough, and flexible

-makes up fetal skeleton

- adult –trachea rings, nose, costal area of ribs

2. Types of Cartilage

B. Elastic

-elastic fibers

-outer ear

2. Types of Cartilage

C. Fibrocartilage

-many collagen fibers, little matrix

-between vertebrae, cushions, absorbs shock

3. Osseous Tissue/Bone

A. Matrix is solid, made of

1. collagen fibers

2. calcium salts

B. Cells are osteocytes, located in nests called “lacunae”

C. Covered with periosteum- has fibrous layer for attachment, and cellular layer for repair

Spongy Bone

• Made of trabeculae• Contain lacunae and osteocytes

CT Classification

CT

properfluid supporting

dense loose

Areolar

adipose

reticular

I

rregular

regular

blood

lymph

cartilage bone

fiborous

elastic

hylaine

spongy

compact

elastic